FSU Fox's Lab Wiki - User contributions [en]

Tandem Beamline Isolation (Fast Valve) System

2026-02-26T15:34:51Z

Pbarber: /* PLC Programming */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC, the offending sensor is recorded, and the system will enter fault mode. All of the beamline isolation valves will immediately shut, with the exception of the SNICS Source exit valve. This valve remains open to sustain pumping on the source inflector magnet section, unless the SNICS Source sensor originates the fault. In this case, the SNICS Source exit valve will shut also.

The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valves may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips, even if the failure has not been addressed yet.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to support useful troubleshooting, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As of this writing (05 Dec 2025), the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible. A PDF version of the program can be accessed at the following link:

[[Media:FV INTLK TANDEM Ver 3r0 26feb26.pdf]]

The wiki does not permit my uploading the click data file. I'll consult for other possibilities and note them here.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. An Automation Direct QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond [https://www.newark.com/hammond/513-0900/enclosure-instrument-steel-gray/dp/73J4427 513-0900] aluminum box.

Note to self: Include the VCP bill of materials here somewhere.

Tandem Beamline Isolation (Fast Valve) System

2026-02-26T15:31:34Z

Pbarber: /* PLC Programming */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC, the offending sensor is recorded, and the system will enter fault mode. All of the beamline isolation valves will immediately shut, with the exception of the SNICS Source exit valve. This valve remains open to sustain pumping on the source inflector magnet section, unless the SNICS Source sensor originates the fault. In this case, the SNICS Source exit valve will shut also.

The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valves may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips, even if the failure has not been addressed yet.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to support useful troubleshooting, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As of this writing (05 Dec 2025), the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

[[Media:FV INTLK TANDEM Ver 3r0 26feb26.pdf]]

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. An Automation Direct QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond [https://www.newark.com/hammond/513-0900/enclosure-instrument-steel-gray/dp/73J4427 513-0900] aluminum box.

Note to self: Include the VCP bill of materials here somewhere.

Tandem Beamline Isolation (Fast Valve) System

2026-02-26T15:30:46Z

Pbarber: /* PLC Programming */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC, the offending sensor is recorded, and the system will enter fault mode. All of the beamline isolation valves will immediately shut, with the exception of the SNICS Source exit valve. This valve remains open to sustain pumping on the source inflector magnet section, unless the SNICS Source sensor originates the fault. In this case, the SNICS Source exit valve will shut also.

The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valves may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips, even if the failure has not been addressed yet.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to support useful troubleshooting, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As of this writing (05 Dec 2025), the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

[[Media:FV INTLK TANDEM Ver 3r0 26feb26.ogg]]

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. An Automation Direct QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond [https://www.newark.com/hammond/513-0900/enclosure-instrument-steel-gray/dp/73J4427 513-0900] aluminum box.

Note to self: Include the VCP bill of materials here somewhere.

Tandem Beamline Isolation (Fast Valve) System

2026-02-26T15:30:16Z

Pbarber: /* PLC Programming */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC, the offending sensor is recorded, and the system will enter fault mode. All of the beamline isolation valves will immediately shut, with the exception of the SNICS Source exit valve. This valve remains open to sustain pumping on the source inflector magnet section, unless the SNICS Source sensor originates the fault. In this case, the SNICS Source exit valve will shut also.

The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valves may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips, even if the failure has not been addressed yet.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to support useful troubleshooting, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As of this writing (05 Dec 2025), the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

[[Media:FV INTLK TANDEM Ver 3r0 26feb26.pdf.ogg]]

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. An Automation Direct QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond [https://www.newark.com/hammond/513-0900/enclosure-instrument-steel-gray/dp/73J4427 513-0900] aluminum box.

Note to self: Include the VCP bill of materials here somewhere.

File:FV INTLK TANDEM Ver 3r0 26feb26.pdf

2026-02-26T15:27:05Z

Pbarber:

Standard Laboratory Vacuum System Stations

2026-02-11T16:04:17Z

Pbarber: /* Maintenance */

== Standard Laboratory Vacuum System Stations ==
=== Introduction ===
In order to achieve high vacuum (nominally ~ 1 x 10E-6 Torr) it is necessary to combine various vacuum technology components into a system, sometimes colloquially referred to as a "stack." Throughout our lab, there are vacuum stations that are used to achieve high vacuum in different sections of the accelerator. Typically, anywhere the beamlines or accelerator can be separated by isolation valves, a station exists between those valves. It is undesirable to have a "dead section" of beamline - a section that is isolated by valves but without a vacuum station. This page explains the basic stacks or systems in use at each station throughout our lab.

=== Turbo-Pump Based Stations ===
The Turbo-Pump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Turbo (short for Turbomolecular) pump systems are ''throughput'' pumping systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Turbo pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the turbo's discharge port and atmosphere. In our lab, this roughing pump is typically an oil-sealed, rotary-vane vacuum pump but may sometimes be an oil-free, dry scroll pump.

The standard turbo pump station consists of the following components:
* A single turbomolecular vacuum pump.
* A single roughing pump.
* An electro-pneumatically operated, high-throughput, gate valve.
* A hand operated (usually) or an electro-pneumatically operated (rarely) foreline valve.
* A molecular-sieve foreline trap.
* A foreline vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the turbo and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the turbo inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the turbo pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the turbo is in NORMAL OPERATION (running at full speed)''' and that the foreline pressure is good ( < 50 mTorr ). Some of our turbos have a LOW SPEED setting that can be employed when not in use to prolong bearing life. The turbo should be brought to full speed before placing online.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below a few hundred millitor and quickly recover. Danger to the turbo can occur if the foreline remains well above 50 mTorr for a prolonged period (10's of minutes). Prolonged exposures to high foreline pressures will cause bearing overheating and pump shut-down. Never walk off and leave a turbo running w/ high foreline pressures. If the foreline pressure fails to start dropping within a few minutes, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a turbo pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Be mindful of turbo pump temperature and foreline pressure until both are back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the turbo's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the turbo is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.
*'''MagLev Crash''': A rapid gas inrush in a magnetically levitated turbo can overwhelm the magnetic field bearings and cause the turbo to "sit down" on it's emergency bearings. When this occurs the turbo will "scream" loudly and can easily startle nearby personnel. MagLev crashes should be avoided if at all possible. Most maglev turbos have a limited number of times that this may occur before the emergency bearings must be replaced at significant cost.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

All of the turbo pumps in operation in our lab use one of two bearing types: (1) static or dynamic magnetic bearings, or (2) permanently lubricated ceramic ball bearings. In both of these cases, the pumps are run until failure. Some of our turbos have a hybrid bearing technology where one bearing is magnetic, but the other is ceramic ball. The Re-Buncher turbo does have a battery that must be replaced periodically. Cooling fan operation must be maintained when in operation unless approved by staff. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

=== Cryopump Based Stations ===
The Cryopump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Cryopumps are ''capture'' pumps, which means that the gases that are removed from the evacuated space are stored within the pump until the pump's capacity is reached. These gases must then be expelled through a process known as regeneration. Modern cryopumps can do this automatically. Sadly, our cryopumps are not modern cryopumps and regeneration must be done manually.

The standard cryopump station consists of the following components:
* A single cryopump.
* A single cryopump compressor.
* An electro-pneumatically operated, high-throughput, gate valve.
* A pump-mounted vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
A cryopump is a capture pump and will run continuously until one of the following occurs:
#Operation is interrupted long enough to allow the pump to warm and break its vacuum insulation
#Pump capacity is reached.
#Pump Failure occurs.

In a cryopump based vacuum station, the cryopump runs 24/7 and captures gas from the chamber by cryo-condensation and cryo-adsorption. If lab operations dictate that the beamline or chamber be vented, then the cryopump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 30 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the cryopump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 30 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the cryopump is cold''' (< ~ 25K) and that the pump pressure is low (< ~ 10 mTorr).
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the chamber/beamline pressure''' and ensure that it begins to fall. This should occur rapidly, as our standard cryopump provides a very high pumping speed for water vapor and nitrogen - the predominant gases in atmosphere. Check periodically to ensure that the system achieves a nominal pressure and the pump temperature remains nominal.

'''CAUTIONS'''
*Opening the cryopump when the chamber pressure is too high can cause the cryopump to "crash" or warm up beyond recovery.
*When warming, cryopumps can overpressure. All cryopumps have a pressure relief device of some kind, typically a spring-loaded, elastomer-sealed valve.
{{ Warning | The LE Tandem, HE Tandem, and TR1 Analyzing Magnet cryopump pressure relief valves have been modified with a relief valve capture device. This device encases the relief valve and directs any gas from it through a red polyethylene tube to the Tritium Source fume hood. DO NOT alter, modify, or otherwise disturb this system without speaking to the Tritium Source team. }}
Cryopumps designed for ultra-high vacuum systems may also have a single-use burst disk which ruptures violently when actuated. (none of our cryopumps have burst disks)
*When warming, the external cryopanel housing can become so cold that it condenses water vapor and can create a drip hazard for equipment located below it.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

Maintenance actions involving cryopumps almost always require thermal cycling and therefore can involve prolonged periods of time. It is not uncommon to lose the better part of a day of data collection due to a cryopump issue.

{{ Warning | Since the addition of the Tritium Source, Tandem Accelerator Cryopump maintenance procedures have been altered to allow for the possibility of tritium accumulation in the pump. Maintenance should only be performed by qualified personnel in consultation with the Tritium Source team. As of this writing, the procedures are in flux and thus can not be delineated here. The following information applies in general to a cryopump w/o the possibility of contamination and remain here now for educational purposes only. }}
Common cryopump maintenance actions include:
#'''Regeneration'''. This is the process of ridding the pump of the captured gas. Regeneration is needed when the pump reaches capacity or develops a cold short--an ice bridge between the interior cryopanels and exterior housing which prevents the pump from achieving it's operating temperature. Regeneration requires thermal cycling. Typically regeneration is performed by staff during normal business hours. All other maintenance actions will require regeneration as part of the maintenance action. The following procedure for regeneration is provided in case those unfamiliar with the process are required to perform it to restore operations.
##'''Isolate the cryopump''' from the vacuum chamber or beamline by shutting the gate valve. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve.
##'''Turn off the cryopump compressor'''.
##'''Vent the cryopump'''. Locate a source of dry nitrogen, if possible, and use this to vent the cryopump. Allow the cryopump to come to atmospheric pressure. Use caution when connecting the dry nitrogen source and ensure that the pump is never over-pressured.
##'''Open the relief valve'''. Carefully pull the relief valve open and place something relatively soft in the elastomer seal to prevent closure. A wooden cotton swab handle or a nylon tie-wrap works well.
##'''Start Dry Nitrogen Bleed'''. Establish a slow-flow from the dry nitrogen line and connect it to the pump-out valve so that a small amount of dry nitrogen flows through the pump and out of the relief valve.
##'''Start the Heater'''. If one exist, initiate heating on the housing. This is typically done w/ a silicone heat-tape wrapped around the pump housing. '''CAUTION''': Be sure to follow any instructions on the heater control. Over heating the pump can melt the indium components!
##'''Monitor the pump temperature'''. Allow the pump to come to room temperature, or slightly above. Some of our pumps have silicon diode thermometry and will read the temperature fairly well throughout the range to ambient. Other pumps have hydrogen vapor pressure thermometry and do not accurately read the temperature above the low Kelvin range. Allow these pumps to warm/flow for '''at least''' two hours, and up to four if possible.
##'''Stop Dry Nitrogen Flow'''. Once the pump has reached ambient temperature or slightly above, stop the flow of nitrogen. Remove the nitrogen source connection. Remove the device that was used to hold the relief valve open and visually confirm that it closes properly.
##'''Turn Off Heating'''. If a heater was used to warm the pump during flow, turn it off now.
##'''Pump out the Cryopanels'''. Connect an oil-free pumping cart to the cryopump and initate pumping. It can take a while to pump out a cryopump, but if the pump was fully warmed and flowed, it should be done in less than two hours.
##'''Test the Pump Out'''. Verify that the pump is fully evacuated by ensuring the following criteria: (1) pump pressure is 30 mTorr or less, and (2) the pressure in the pump has a rate of rise < 15 mTorr/min when the roughing cart is isolated from the pump. If these criteria are met, re-open the valve to the scroll cart and proceed to the next step.
##'''Restart the Cryopump'''. Using the switch on the compressor, restart the cryopump and allow it to run.
##'''Stop the Pump Out'''. Within about 10 mins of starting the compressor, shut the valve to isolate the scroll cart.
##'''Monitor the Pump'''. On pumps with silicon diode thermometry, one need only monitor the temperature display and verify that the pump is cooling down. On pumps with hydrogen vapor bulb thermometry, there will be no visible sign of temperature change until the pump is in the tens of Kelvin range. On these pumps, the pump pressure should be monitored for indications that the pump pressure is dropping and that this pressure drop occurs within a few tens of minutes. Once temperature and/or pressure drop are confirmed, one need simply wait for the pump to achieve nominal operating temperature. This should usually occur in 2-3 hours.
##'''Place Pump in Service'''. Once the pump has achieved nominal operating temperature, verify that the chamber pressure is below 30 mTorr (the lower the better) and then open the gate valve. Verify that the chamber pressure drops rapidly. Monitor the pump pressure for the next few tens of minutes to ensure the cryopump doesn't crash (become overwhelmed and warm up).
##'''Paperwork'''. If there exists a tag on the cryopump, mark the date and the fact that regeneration was performed for future reference.
#'''Cold Head Purge'''. This involves removing contaminant gases from the cold head. During normal operation, gases other than helium will tend to freeze withing the cold head's (pump's) helium circuit and impair operations. If allowed to build too much, this ice can mechanically damage components in the cold head. Similar to regeneration, the pump is stopped and the cold head is disconnected quickly from the compressor. Once warm, the thawed contaminant gases are purged from the cold head's helium circuit. Cold head purge require implicit regeneration of the cryopanels.
#'''Compressor Purge'''. When contaminant gases are significant, it can be necessary to purge the compressor as well. Compressor Purges require implicit Cold Head Purge and Cryopanel Regeneration.
#'''Adsorber Change'''. This is a scheduled, preventive maintenance action, typically performed annually. The adorber is basically an oil filter that prevents compressor oil from entering the cold head. Failure to perform this maintenance on schedule will result in contamination and failure of the cold head and necessitate a costly rebuild. Adsorber changes require implicit Cryopanel Regeneration, and usually include Cold Head Purges as well.

=== Diffusion Pump Based Stations (rare) ===

The Diffusion Pump Based Vacuum Station is a system used to produce high vacuum (10-6 < X < 10-9 Torr ) in some specialized systems within the laboratory, notably the SNICS source and one of the target lab evaporators. Diffusion pumps, in general, are being replaced by more modern alternatives and are typically no longer included in new designs. Feel free to skip this section if you're short on time. Diffusion pump systems are ''throughput'' systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Diffusion pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the diffusion pump's discharge port and atmosphere. In our lab, this roughing pump is an oil-sealed, rotary-vane vacuum pump.

The standard diffusion pump station consists of the following components:
* A single diffusion pump.
* A single roughing pump.
* An electro-pneumatically or manually operated, high-throughput, gate valve.
* An electro-pneumatically or manually operated foreline valve.
* A foreline vacuum pump gauge
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit. (on some systems)
* A panel-mounted indicator & control panel. (on some systems)
* A source of water cooling.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the diffusion pump and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the diffusion pump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the diffusion pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the diffusion pump is at its operating temperature and has water cooling''' and that the foreline pressure is good ( < 50 mTorr ). If a refrigerated baffle or cryotrap is installed, verify that it is functional and/or filled and thus cold.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below 300 millitor and quickly recover. If the foreline pressure fails to start dropping within a minute, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a diffusion pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Monitor foreline pressure until back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the diffusion pump's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the diffusion pump is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.
Diffusion pumps are surprisingly maintenance free. Occasional oil changes are needed when the oil becomes contaminated, or fractionates beyond tolerance. Sufficient cooling water flow and temperatures must be maintained at all times when the pump is running. The cal-rod or plate heater can fail, as can the high-temperature wiring components. The Klixon thermal safety switch can fail. Loss of cooling water in combination with a Klixon safety switch failure can result in severe to catastrophic damage. Trust me. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Standard Laboratory Vacuum System Stations

2026-02-11T15:55:00Z

Pbarber: /* Turbo-Pump Based Stations */

== Standard Laboratory Vacuum System Stations ==
=== Introduction ===
In order to achieve high vacuum (nominally ~ 1 x 10E-6 Torr) it is necessary to combine various vacuum technology components into a system, sometimes colloquially referred to as a "stack." Throughout our lab, there are vacuum stations that are used to achieve high vacuum in different sections of the accelerator. Typically, anywhere the beamlines or accelerator can be separated by isolation valves, a station exists between those valves. It is undesirable to have a "dead section" of beamline - a section that is isolated by valves but without a vacuum station. This page explains the basic stacks or systems in use at each station throughout our lab.

=== Turbo-Pump Based Stations ===
The Turbo-Pump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Turbo (short for Turbomolecular) pump systems are ''throughput'' pumping systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Turbo pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the turbo's discharge port and atmosphere. In our lab, this roughing pump is typically an oil-sealed, rotary-vane vacuum pump but may sometimes be an oil-free, dry scroll pump.

The standard turbo pump station consists of the following components:
* A single turbomolecular vacuum pump.
* A single roughing pump.
* An electro-pneumatically operated, high-throughput, gate valve.
* A hand operated (usually) or an electro-pneumatically operated (rarely) foreline valve.
* A molecular-sieve foreline trap.
* A foreline vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the turbo and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the turbo inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the turbo pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the turbo is in NORMAL OPERATION (running at full speed)''' and that the foreline pressure is good ( < 50 mTorr ). Some of our turbos have a LOW SPEED setting that can be employed when not in use to prolong bearing life. The turbo should be brought to full speed before placing online.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below a few hundred millitor and quickly recover. Danger to the turbo can occur if the foreline remains well above 50 mTorr for a prolonged period (10's of minutes). Prolonged exposures to high foreline pressures will cause bearing overheating and pump shut-down. Never walk off and leave a turbo running w/ high foreline pressures. If the foreline pressure fails to start dropping within a few minutes, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a turbo pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Be mindful of turbo pump temperature and foreline pressure until both are back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the turbo's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the turbo is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.
*'''MagLev Crash''': A rapid gas inrush in a magnetically levitated turbo can overwhelm the magnetic field bearings and cause the turbo to "sit down" on it's emergency bearings. When this occurs the turbo will "scream" loudly and can easily startle nearby personnel. MagLev crashes should be avoided if at all possible. Most maglev turbos have a limited number of times that this may occur before the emergency bearings must be replaced at significant cost.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

All of the turbo pumps in operation in our lab use one of two bearing types: (1) static or dynamic magnetic bearings, or (2) permanently lubricated ceramic ball bearings. In both of these cases, the pumps are run until failure. Some of our turbos have a hybrid bearing technology where one bearing is magnetic, but the other is ceramic ball. The Re-Buncher turbo does have a battery that must be replaced periodically. Cooling fan operation must be maintained when in operation unless approved by staff. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

=== Cryopump Based Stations ===
The Cryopump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Cryopumps are ''capture'' pumps, which means that the gases that are removed from the evacuated space are stored within the pump until the pump's capacity is reached. These gases must then be expelled through a process known as regeneration. Modern cryopumps can do this automatically. Sadly, our cryopumps are not modern cryopumps and regeneration must be done manually.

The standard cryopump station consists of the following components:
* A single cryopump.
* A single cryopump compressor.
* An electro-pneumatically operated, high-throughput, gate valve.
* A pump-mounted vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
A cryopump is a capture pump and will run continuously until one of the following occurs:
#Operation is interrupted long enough to allow the pump to warm and break its vacuum insulation
#Pump capacity is reached.
#Pump Failure occurs.

In a cryopump based vacuum station, the cryopump runs 24/7 and captures gas from the chamber by cryo-condensation and cryo-adsorption. If lab operations dictate that the beamline or chamber be vented, then the cryopump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 30 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the cryopump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 30 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the cryopump is cold''' (< ~ 25K) and that the pump pressure is low (< ~ 10 mTorr).
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the chamber/beamline pressure''' and ensure that it begins to fall. This should occur rapidly, as our standard cryopump provides a very high pumping speed for water vapor and nitrogen - the predominant gases in atmosphere. Check periodically to ensure that the system achieves a nominal pressure and the pump temperature remains nominal.

'''CAUTIONS'''
*Opening the cryopump when the chamber pressure is too high can cause the cryopump to "crash" or warm up beyond recovery.
*When warming, cryopumps can overpressure. All cryopumps have a pressure relief device of some kind, typically a spring-loaded, elastomer-sealed valve.
{{ Warning | The LE Tandem, HE Tandem, and TR1 Analyzing Magnet cryopump pressure relief valves have been modified with a relief valve capture device. This device encases the relief valve and directs any gas from it through a red polyethylene tube to the Tritium Source fume hood. DO NOT alter, modify, or otherwise disturb this system without speaking to the Tritium Source team. }}
Cryopumps designed for ultra-high vacuum systems may also have a single-use burst disk which ruptures violently when actuated. (none of our cryopumps have burst disks)
*When warming, the external cryopanel housing can become so cold that it condenses water vapor and can create a drip hazard for equipment located below it.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

Maintenance actions involving cryopumps almost always involve thermal cycling and therefore can involve prolonged periods of time. It is not uncommon to lose the better part of a day of data collection due to a cryopump issue.

{{ Warning | Since the addition of the Tritium Source, Tandem Accelerator Cryopump maintenance procedures have been altered to allow for the possibility of tritium accumulation in the pump. Maintenance should only be performed by qualified personnel in consultation with the Tritium Source team. As of this writing, the procedures are in flux and thus can not be delineated here. The following information applies in general to a cryopump w/o the possibility of contamination and remain here now for educational purposes only. }}
Common cryopump maintenance actions include:
#'''Regeneration'''. This is the process of ridding the pump of the captured gas. Regeneration is needed when the pump reaches capacity or develops a cold short--an ice bridge between the interior cryopanels and exterior housing which prevents the pump from achieving it's operating temperature. Regeneration requires thermal cycling. Typically regeneration is performed by staff during normal business hours. All other maintenance actions will require regeneration as part of the maintenance action. The following procedure for regeneration is provided in case those unfamiliar with the process are required to perform it to restore operations.
##'''Isolate the cryopump''' from the vacuum chamber or beamline by shutting the gate valve. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve.
##'''Turn off the cryopump compressor'''.
##'''Vent the cryopump'''. Locate a source of dry nitrogen, if possible, and use this to vent the cryopump. Allow the cryopump to come to atmospheric pressure. Use caution when connecting the dry nitrogen source and ensure that the pump is never over-pressured.
##'''Open the relief valve'''. Carefully pull the relief valve open and place something relatively soft in the elastomer seal to prevent closure. A wooden cotton swab handle or a nylon tie-wrap works well.
##'''Start Dry Nitrogen Bleed'''. Establish a slow-flow from the dry nitrogen line and connect it to the pump-out valve so that a small amount of dry nitrogen flows through the pump and out of the relief valve.
##'''Start the Heater'''. If one exist, initiate heating on the housing. This is typically done w/ a silicone heat-tape wrapped around the pump housing. '''CAUTION''': Be sure to follow any instructions on the heater control. Over heating the pump can melt the indium components!
##'''Monitor the pump temperature'''. Allow the pump to come to room temperature, or slightly above. Some of our pumps have silicon diode thermometry and will read the temperature fairly well throughout the range to ambient. Other pumps have hydrogen vapor pressure thermometry and do not accurately read the temperature above the low Kelvin range. Allow these pumps to warm/flow for '''at least''' two hours, and up to four if possible.
##'''Stop Dry Nitrogen Flow'''. Once the pump has reached ambient temperature or slightly above, stop the flow of nitrogen. Remove the nitrogen source connection. Remove the device that was used to hold the relief valve open and visually confirm that it closes properly.
##'''Turn Off Heating'''. If a heater was used to warm the pump during flow, turn it off now.
##'''Pump out the Cryopanels'''. Connect an oil-free pumping cart to the cryopump and initate pumping. It can take a while to pump out a cryopump, but if the pump was fully warmed and flowed, it should be done in less than two hours.
##'''Test the Pump Out'''. Verify that the pump is fully evacuated by ensuring the following criteria: (1) pump pressure is 30 mTorr or less, and (2) the pressure in the pump has a rate of rise < 15 mTorr/min when the roughing cart is isolated from the pump. If these criteria are met, re-open the valve to the scroll cart and proceed to the next step.
##'''Restart the Cryopump'''. Using the switch on the compressor, restart the cryopump and allow it to run.
##'''Stop the Pump Out'''. Within about 10 mins of starting the compressor, shut the valve to isolate the scroll cart.
##'''Monitor the Pump'''. On pumps with silicon diode thermometry, one need only monitor the temperature display and verify that the pump is cooling down. On pumps with hydrogen vapor bulb thermometry, there will be no visible sign of temperature change until the pump is in the tens of Kelvin range. On these pumps, the pump pressure should be monitored for indications that the pump pressure is dropping and that this pressure drop occurs within a few tens of minutes. Once temperature and/or pressure drop are confirmed, one need simply wait for the pump to achieve nominal operating temperature. This should usually occur in 2-3 hours.
##'''Place Pump in Service'''. Once the pump has achieved nominal operating temperature, verify that the chamber pressure is below 30 mTorr (the lower the better) and then open the gate valve. Verify that the chamber pressure drops rapidly. Monitor the pump pressure for the next few tens of minutes to ensure the cryopump doesn't crash (become overwhelmed and warm up).
##'''Paperwork'''. If there exists a tag on the cryopump, mark the date and the fact that regeneration was performed for future reference.
#'''Cold Head Purge'''. This involves removing contaminant gases from the cold head. During normal operation, gases other than helium will tend to freeze withing the cold head's (pump's) helium circuit and impair operations. If allowed to build too much, this ice can mechanically damage components in the cold head. Similar to regeneration, the pump is stopped and the cold head is disconnected quickly from the compressor. Once warm, the thawed contaminant gases are purged from the cold head's helium circuit. Cold head purge require implicit regeneration of the cryopanels.
#'''Compressor Purge'''. When contaminant gases are significant, it can be necessary to purge the compressor as well. Compressor Purges require implicit Cold Head Purge and Cryopanel Regeneration.
#'''Adsorber Change'''. This is a scheduled, preventive maintenance action, typically performed annually. The adorber is basically an oil filter that prevents compressor oil from entering the cold head. Failure to perform this maintenance on schedule will result in contamination and failure of the cold head and necessitate a costly rebuild. Adsorber changes require implicit Cryopanel Regeneration, and usually include Cold Head Purges as well.

=== Diffusion Pump Based Stations (rare) ===

The Diffusion Pump Based Vacuum Station is a system used to produce high vacuum (10-6 < X < 10-9 Torr ) in some specialized systems within the laboratory, notably the SNICS source and one of the target lab evaporators. Diffusion pumps, in general, are being replaced by more modern alternatives and are typically no longer included in new designs. Feel free to skip this section if you're short on time. Diffusion pump systems are ''throughput'' systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Diffusion pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the diffusion pump's discharge port and atmosphere. In our lab, this roughing pump is an oil-sealed, rotary-vane vacuum pump.

The standard diffusion pump station consists of the following components:
* A single diffusion pump.
* A single roughing pump.
* An electro-pneumatically or manually operated, high-throughput, gate valve.
* An electro-pneumatically or manually operated foreline valve.
* A foreline vacuum pump gauge
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit. (on some systems)
* A panel-mounted indicator & control panel. (on some systems)
* A source of water cooling.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the diffusion pump and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the diffusion pump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the diffusion pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the diffusion pump is at its operating temperature and has water cooling''' and that the foreline pressure is good ( < 50 mTorr ). If a refrigerated baffle or cryotrap is installed, verify that it is functional and/or filled and thus cold.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below 300 millitor and quickly recover. If the foreline pressure fails to start dropping within a minute, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a diffusion pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Monitor foreline pressure until back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the diffusion pump's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the diffusion pump is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.
Diffusion pumps are surprisingly maintenance free. Occasional oil changes are needed when the oil becomes contaminated, or fractionates beyond tolerance. Sufficient cooling water flow and temperatures must be maintained at all times when the pump is running. The cal-rod or plate heater can fail, as can the high-temperature wiring components. The Klixon thermal safety switch can fail. Loss of cooling water in combination with a Klixon safety switch failure can result in severe to catastrophic damage. Trust me. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Standard Laboratory Vacuum System Stations

2026-02-11T15:53:22Z

Pbarber: /* Introduction */

== Standard Laboratory Vacuum System Stations ==
=== Introduction ===
In order to achieve high vacuum (nominally ~ 1 x 10E-6 Torr) it is necessary to combine various vacuum technology components into a system, sometimes colloquially referred to as a "stack." Throughout our lab, there are vacuum stations that are used to achieve high vacuum in different sections of the accelerator. Typically, anywhere the beamlines or accelerator can be separated by isolation valves, a station exists between those valves. It is undesirable to have a "dead section" of beamline - a section that is isolated by valves but without a vacuum station. This page explains the basic stacks or systems in use at each station throughout our lab.

=== Turbo-Pump Based Stations ===
The Turbo-Pump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Turbo pump, or more exactingly turbomolecular pump, systems are ''throughput'' pumping systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Turbo pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the turbo's discharge port and atmosphere. In our lab, this roughing pump is typically an oil-sealed, rotary-vane vacuum pump but may sometimes be an oil-free, dry scroll pump.

The standard turbo pump station consists of the following components:
* A single turbomolecular vacuum pump.
* A single roughing pump.
* An electro-pneumatically operated, high-throughput, gate valve.
* A hand operated (usually) or an electro-pneumatically operated (rarely) foreline valve.
* A molecular-sieve foreline trap.
* A foreline vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the turbo and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the turbo inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the turbo pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the turbo is in NORMAL OPERATION (running at full speed)''' and that the foreline pressure is good ( < 50 mTorr ). Some of our turbos have a LOW SPEED setting that can be employed when not in use to prolong bearing life. The turbo should be brought to full speed before placing online.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below a few hundred millitor and quickly recover. Danger to the turbo can occur if the foreline remains well above 50 mTorr for a prolonged period (10's of minutes). Prolonged exposures to high foreline pressures will cause bearing overheating and pump shut-down. Never walk off and leave a turbo running w/ high foreline pressures. If the foreline pressure fails to start dropping within a few minutes, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a turbo pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Be mindful of turbo pump temperature and foreline pressure until both are back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the turbo's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the turbo is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.
*'''MagLev Crash''': A rapid gas inrush in a magnetically levitated turbo can overwhelm the magnetic field bearings and cause the turbo to "sit down" on it's emergency bearings. When this occurs the turbo will "scream" loudly and can easily startle nearby personnel. MagLev crashes should be avoided if at all possible. Most maglev turbos have a limited number of times that this may occur before the emergency bearings must be replaced at significant cost.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

All of the turbo pumps in operation in our lab use one of two bearing types: (1) static or dynamic magnetic bearings, or (2) permanently lubricated ceramic ball bearings. In both of these cases, the pumps are run until failure. Some of our turbos have a hybrid bearing technology where one bearing is magnetic, but the other is ceramic ball. The Re-Buncher turbo does have a battery that must be replaced periodically. Cooling fan operation must be maintained when in operation unless approved by staff. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

=== Cryopump Based Stations ===
The Cryopump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Cryopumps are ''capture'' pumps, which means that the gases that are removed from the evacuated space are stored within the pump until the pump's capacity is reached. These gases must then be expelled through a process known as regeneration. Modern cryopumps can do this automatically. Sadly, our cryopumps are not modern cryopumps and regeneration must be done manually.

The standard cryopump station consists of the following components:
* A single cryopump.
* A single cryopump compressor.
* An electro-pneumatically operated, high-throughput, gate valve.
* A pump-mounted vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
A cryopump is a capture pump and will run continuously until one of the following occurs:
#Operation is interrupted long enough to allow the pump to warm and break its vacuum insulation
#Pump capacity is reached.
#Pump Failure occurs.

In a cryopump based vacuum station, the cryopump runs 24/7 and captures gas from the chamber by cryo-condensation and cryo-adsorption. If lab operations dictate that the beamline or chamber be vented, then the cryopump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 30 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the cryopump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 30 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the cryopump is cold''' (< ~ 25K) and that the pump pressure is low (< ~ 10 mTorr).
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the chamber/beamline pressure''' and ensure that it begins to fall. This should occur rapidly, as our standard cryopump provides a very high pumping speed for water vapor and nitrogen - the predominant gases in atmosphere. Check periodically to ensure that the system achieves a nominal pressure and the pump temperature remains nominal.

'''CAUTIONS'''
*Opening the cryopump when the chamber pressure is too high can cause the cryopump to "crash" or warm up beyond recovery.
*When warming, cryopumps can overpressure. All cryopumps have a pressure relief device of some kind, typically a spring-loaded, elastomer-sealed valve.
{{ Warning | The LE Tandem, HE Tandem, and TR1 Analyzing Magnet cryopump pressure relief valves have been modified with a relief valve capture device. This device encases the relief valve and directs any gas from it through a red polyethylene tube to the Tritium Source fume hood. DO NOT alter, modify, or otherwise disturb this system without speaking to the Tritium Source team. }}
Cryopumps designed for ultra-high vacuum systems may also have a single-use burst disk which ruptures violently when actuated. (none of our cryopumps have burst disks)
*When warming, the external cryopanel housing can become so cold that it condenses water vapor and can create a drip hazard for equipment located below it.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

Maintenance actions involving cryopumps almost always involve thermal cycling and therefore can involve prolonged periods of time. It is not uncommon to lose the better part of a day of data collection due to a cryopump issue.

{{ Warning | Since the addition of the Tritium Source, Tandem Accelerator Cryopump maintenance procedures have been altered to allow for the possibility of tritium accumulation in the pump. Maintenance should only be performed by qualified personnel in consultation with the Tritium Source team. As of this writing, the procedures are in flux and thus can not be delineated here. The following information applies in general to a cryopump w/o the possibility of contamination and remain here now for educational purposes only. }}
Common cryopump maintenance actions include:
#'''Regeneration'''. This is the process of ridding the pump of the captured gas. Regeneration is needed when the pump reaches capacity or develops a cold short--an ice bridge between the interior cryopanels and exterior housing which prevents the pump from achieving it's operating temperature. Regeneration requires thermal cycling. Typically regeneration is performed by staff during normal business hours. All other maintenance actions will require regeneration as part of the maintenance action. The following procedure for regeneration is provided in case those unfamiliar with the process are required to perform it to restore operations.
##'''Isolate the cryopump''' from the vacuum chamber or beamline by shutting the gate valve. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve.
##'''Turn off the cryopump compressor'''.
##'''Vent the cryopump'''. Locate a source of dry nitrogen, if possible, and use this to vent the cryopump. Allow the cryopump to come to atmospheric pressure. Use caution when connecting the dry nitrogen source and ensure that the pump is never over-pressured.
##'''Open the relief valve'''. Carefully pull the relief valve open and place something relatively soft in the elastomer seal to prevent closure. A wooden cotton swab handle or a nylon tie-wrap works well.
##'''Start Dry Nitrogen Bleed'''. Establish a slow-flow from the dry nitrogen line and connect it to the pump-out valve so that a small amount of dry nitrogen flows through the pump and out of the relief valve.
##'''Start the Heater'''. If one exist, initiate heating on the housing. This is typically done w/ a silicone heat-tape wrapped around the pump housing. '''CAUTION''': Be sure to follow any instructions on the heater control. Over heating the pump can melt the indium components!
##'''Monitor the pump temperature'''. Allow the pump to come to room temperature, or slightly above. Some of our pumps have silicon diode thermometry and will read the temperature fairly well throughout the range to ambient. Other pumps have hydrogen vapor pressure thermometry and do not accurately read the temperature above the low Kelvin range. Allow these pumps to warm/flow for '''at least''' two hours, and up to four if possible.
##'''Stop Dry Nitrogen Flow'''. Once the pump has reached ambient temperature or slightly above, stop the flow of nitrogen. Remove the nitrogen source connection. Remove the device that was used to hold the relief valve open and visually confirm that it closes properly.
##'''Turn Off Heating'''. If a heater was used to warm the pump during flow, turn it off now.
##'''Pump out the Cryopanels'''. Connect an oil-free pumping cart to the cryopump and initate pumping. It can take a while to pump out a cryopump, but if the pump was fully warmed and flowed, it should be done in less than two hours.
##'''Test the Pump Out'''. Verify that the pump is fully evacuated by ensuring the following criteria: (1) pump pressure is 30 mTorr or less, and (2) the pressure in the pump has a rate of rise < 15 mTorr/min when the roughing cart is isolated from the pump. If these criteria are met, re-open the valve to the scroll cart and proceed to the next step.
##'''Restart the Cryopump'''. Using the switch on the compressor, restart the cryopump and allow it to run.
##'''Stop the Pump Out'''. Within about 10 mins of starting the compressor, shut the valve to isolate the scroll cart.
##'''Monitor the Pump'''. On pumps with silicon diode thermometry, one need only monitor the temperature display and verify that the pump is cooling down. On pumps with hydrogen vapor bulb thermometry, there will be no visible sign of temperature change until the pump is in the tens of Kelvin range. On these pumps, the pump pressure should be monitored for indications that the pump pressure is dropping and that this pressure drop occurs within a few tens of minutes. Once temperature and/or pressure drop are confirmed, one need simply wait for the pump to achieve nominal operating temperature. This should usually occur in 2-3 hours.
##'''Place Pump in Service'''. Once the pump has achieved nominal operating temperature, verify that the chamber pressure is below 30 mTorr (the lower the better) and then open the gate valve. Verify that the chamber pressure drops rapidly. Monitor the pump pressure for the next few tens of minutes to ensure the cryopump doesn't crash (become overwhelmed and warm up).
##'''Paperwork'''. If there exists a tag on the cryopump, mark the date and the fact that regeneration was performed for future reference.
#'''Cold Head Purge'''. This involves removing contaminant gases from the cold head. During normal operation, gases other than helium will tend to freeze withing the cold head's (pump's) helium circuit and impair operations. If allowed to build too much, this ice can mechanically damage components in the cold head. Similar to regeneration, the pump is stopped and the cold head is disconnected quickly from the compressor. Once warm, the thawed contaminant gases are purged from the cold head's helium circuit. Cold head purge require implicit regeneration of the cryopanels.
#'''Compressor Purge'''. When contaminant gases are significant, it can be necessary to purge the compressor as well. Compressor Purges require implicit Cold Head Purge and Cryopanel Regeneration.
#'''Adsorber Change'''. This is a scheduled, preventive maintenance action, typically performed annually. The adorber is basically an oil filter that prevents compressor oil from entering the cold head. Failure to perform this maintenance on schedule will result in contamination and failure of the cold head and necessitate a costly rebuild. Adsorber changes require implicit Cryopanel Regeneration, and usually include Cold Head Purges as well.

=== Diffusion Pump Based Stations (rare) ===

The Diffusion Pump Based Vacuum Station is a system used to produce high vacuum (10-6 < X < 10-9 Torr ) in some specialized systems within the laboratory, notably the SNICS source and one of the target lab evaporators. Diffusion pumps, in general, are being replaced by more modern alternatives and are typically no longer included in new designs. Feel free to skip this section if you're short on time. Diffusion pump systems are ''throughput'' systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Diffusion pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the diffusion pump's discharge port and atmosphere. In our lab, this roughing pump is an oil-sealed, rotary-vane vacuum pump.

The standard diffusion pump station consists of the following components:
* A single diffusion pump.
* A single roughing pump.
* An electro-pneumatically or manually operated, high-throughput, gate valve.
* An electro-pneumatically or manually operated foreline valve.
* A foreline vacuum pump gauge
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit. (on some systems)
* A panel-mounted indicator & control panel. (on some systems)
* A source of water cooling.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the diffusion pump and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the diffusion pump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the diffusion pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the diffusion pump is at its operating temperature and has water cooling''' and that the foreline pressure is good ( < 50 mTorr ). If a refrigerated baffle or cryotrap is installed, verify that it is functional and/or filled and thus cold.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below 300 millitor and quickly recover. If the foreline pressure fails to start dropping within a minute, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a diffusion pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Monitor foreline pressure until back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the diffusion pump's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the diffusion pump is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.
Diffusion pumps are surprisingly maintenance free. Occasional oil changes are needed when the oil becomes contaminated, or fractionates beyond tolerance. Sufficient cooling water flow and temperatures must be maintained at all times when the pump is running. The cal-rod or plate heater can fail, as can the high-temperature wiring components. The Klixon thermal safety switch can fail. Loss of cooling water in combination with a Klixon safety switch failure can result in severe to catastrophic damage. Trust me. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Standard Laboratory Vacuum System Stations

2026-02-09T14:07:25Z

Pbarber: /* Maintenance */

== Standard Laboratory Vacuum System Stations ==
=== Introduction ===
In order to achieve high vacuum (nominally ~ 1 x 10E-6 Torr) it is necessary to combine various vacuum technology components into a system, sometimes colloquially referred to as a "stack." Throughout our lab, there are vacuum stations that are used to achieve high vacuum in different sections of the accelerator. Typically, anywhere the beamlines or accelerator can be separated by isolation valves, a station exists between those valves. It is undesirable to have a "dead section" of beamline - a section that is isolated by valves but without a vacuum station. This page explains the basic stacks or systems in used at each station throughout our lab.
=== Turbo-Pump Based Stations ===
The Turbo-Pump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Turbo pump, or more exactingly turbomolecular pump, systems are ''throughput'' pumping systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Turbo pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the turbo's discharge port and atmosphere. In our lab, this roughing pump is typically an oil-sealed, rotary-vane vacuum pump but may sometimes be an oil-free, dry scroll pump.

The standard turbo pump station consists of the following components:
* A single turbomolecular vacuum pump.
* A single roughing pump.
* An electro-pneumatically operated, high-throughput, gate valve.
* A hand operated (usually) or an electro-pneumatically operated (rarely) foreline valve.
* A molecular-sieve foreline trap.
* A foreline vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the turbo and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the turbo inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the turbo pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the turbo is in NORMAL OPERATION (running at full speed)''' and that the foreline pressure is good ( < 50 mTorr ). Some of our turbos have a LOW SPEED setting that can be employed when not in use to prolong bearing life. The turbo should be brought to full speed before placing online.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below a few hundred millitor and quickly recover. Danger to the turbo can occur if the foreline remains well above 50 mTorr for a prolonged period (10's of minutes). Prolonged exposures to high foreline pressures will cause bearing overheating and pump shut-down. Never walk off and leave a turbo running w/ high foreline pressures. If the foreline pressure fails to start dropping within a few minutes, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a turbo pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Be mindful of turbo pump temperature and foreline pressure until both are back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the turbo's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the turbo is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.
*'''MagLev Crash''': A rapid gas inrush in a magnetically levitated turbo can overwhelm the magnetic field bearings and cause the turbo to "sit down" on it's emergency bearings. When this occurs the turbo will "scream" loudly and can easily startle nearby personnel. MagLev crashes should be avoided if at all possible. Most maglev turbos have a limited number of times that this may occur before the emergency bearings must be replaced at significant cost.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

All of the turbo pumps in operation in our lab use one of two bearing types: (1) static or dynamic magnetic bearings, or (2) permanently lubricated ceramic ball bearings. In both of these cases, the pumps are run until failure. Some of our turbos have a hybrid bearing technology where one bearing is magnetic, but the other is ceramic ball. The Re-Buncher turbo does have a battery that must be replaced periodically. Cooling fan operation must be maintained when in operation unless approved by staff. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

=== Cryopump Based Stations ===
The Cryopump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Cryopumps are ''capture'' pumps, which means that the gases that are removed from the evacuated space are stored within the pump until the pump's capacity is reached. These gases must then be expelled through a process known as regeneration. Modern cryopumps can do this automatically. Sadly, our cryopumps are not modern cryopumps and regeneration must be done manually.

The standard cryopump station consists of the following components:
* A single cryopump.
* A single cryopump compressor.
* An electro-pneumatically operated, high-throughput, gate valve.
* A pump-mounted vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
A cryopump is a capture pump and will run continuously until one of the following occurs:
#Operation is interrupted long enough to allow the pump to warm and break its vacuum insulation
#Pump capacity is reached.
#Pump Failure occurs.

In a cryopump based vacuum station, the cryopump runs 24/7 and captures gas from the chamber by cryo-condensation and cryo-adsorption. If lab operations dictate that the beamline or chamber be vented, then the cryopump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 30 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the cryopump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 30 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the cryopump is cold''' (< ~ 25K) and that the pump pressure is low (< ~ 10 mTorr).
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the chamber/beamline pressure''' and ensure that it begins to fall. This should occur rapidly, as our standard cryopump provides a very high pumping speed for water vapor and nitrogen - the predominant gases in atmosphere. Check periodically to ensure that the system achieves a nominal pressure and the pump temperature remains nominal.

'''CAUTIONS'''
*Opening the cryopump when the chamber pressure is too high can cause the cryopump to "crash" or warm up beyond recovery.
*When warming, cryopumps can overpressure. All cryopumps have a pressure relief device of some kind, typically a spring-loaded, elastomer-sealed valve.
{{ Warning | The LE Tandem, HE Tandem, and TR1 Analyzing Magnet cryopump pressure relief valves have been modified with a relief valve capture device. This device encases the relief valve and directs any gas from it through a red polyethylene tube to the Tritium Source fume hood. DO NOT alter, modify, or otherwise disturb this system without speaking to the Tritium Source team. }}
Cryopumps designed for ultra-high vacuum systems may also have a single-use burst disk which ruptures violently when actuated. (none of our cryopumps have burst disks)
*When warming, the external cryopanel housing can become so cold that it condenses water vapor and can create a drip hazard for equipment located below it.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

Maintenance actions involving cryopumps almost always involve thermal cycling and therefore can involve prolonged periods of time. It is not uncommon to lose the better part of a day of data collection due to a cryopump issue.

{{ Warning | Since the addition of the Tritium Source, Tandem Accelerator Cryopump maintenance procedures have been altered to allow for the possibility of tritium accumulation in the pump. Maintenance should only be performed by qualified personnel in consultation with the Tritium Source team. As of this writing, the procedures are in flux and thus can not be delineated here. The following information applies in general to a cryopump w/o the possibility of contamination and remain here now for educational purposes only. }}
Common cryopump maintenance actions include:
#'''Regeneration'''. This is the process of ridding the pump of the captured gas. Regeneration is needed when the pump reaches capacity or develops a cold short--an ice bridge between the interior cryopanels and exterior housing which prevents the pump from achieving it's operating temperature. Regeneration requires thermal cycling. Typically regeneration is performed by staff during normal business hours. All other maintenance actions will require regeneration as part of the maintenance action. The following procedure for regeneration is provided in case those unfamiliar with the process are required to perform it to restore operations.
##'''Isolate the cryopump''' from the vacuum chamber or beamline by shutting the gate valve. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve.
##'''Turn off the cryopump compressor'''.
##'''Vent the cryopump'''. Locate a source of dry nitrogen, if possible, and use this to vent the cryopump. Allow the cryopump to come to atmospheric pressure. Use caution when connecting the dry nitrogen source and ensure that the pump is never over-pressured.
##'''Open the relief valve'''. Carefully pull the relief valve open and place something relatively soft in the elastomer seal to prevent closure. A wooden cotton swab handle or a nylon tie-wrap works well.
##'''Start Dry Nitrogen Bleed'''. Establish a slow-flow from the dry nitrogen line and connect it to the pump-out valve so that a small amount of dry nitrogen flows through the pump and out of the relief valve.
##'''Start the Heater'''. If one exist, initiate heating on the housing. This is typically done w/ a silicone heat-tape wrapped around the pump housing. '''CAUTION''': Be sure to follow any instructions on the heater control. Over heating the pump can melt the indium components!
##'''Monitor the pump temperature'''. Allow the pump to come to room temperature, or slightly above. Some of our pumps have silicon diode thermometry and will read the temperature fairly well throughout the range to ambient. Other pumps have hydrogen vapor pressure thermometry and do not accurately read the temperature above the low Kelvin range. Allow these pumps to warm/flow for '''at least''' two hours, and up to four if possible.
##'''Stop Dry Nitrogen Flow'''. Once the pump has reached ambient temperature or slightly above, stop the flow of nitrogen. Remove the nitrogen source connection. Remove the device that was used to hold the relief valve open and visually confirm that it closes properly.
##'''Turn Off Heating'''. If a heater was used to warm the pump during flow, turn it off now.
##'''Pump out the Cryopanels'''. Connect an oil-free pumping cart to the cryopump and initate pumping. It can take a while to pump out a cryopump, but if the pump was fully warmed and flowed, it should be done in less than two hours.
##'''Test the Pump Out'''. Verify that the pump is fully evacuated by ensuring the following criteria: (1) pump pressure is 30 mTorr or less, and (2) the pressure in the pump has a rate of rise < 15 mTorr/min when the roughing cart is isolated from the pump. If these criteria are met, re-open the valve to the scroll cart and proceed to the next step.
##'''Restart the Cryopump'''. Using the switch on the compressor, restart the cryopump and allow it to run.
##'''Stop the Pump Out'''. Within about 10 mins of starting the compressor, shut the valve to isolate the scroll cart.
##'''Monitor the Pump'''. On pumps with silicon diode thermometry, one need only monitor the temperature display and verify that the pump is cooling down. On pumps with hydrogen vapor bulb thermometry, there will be no visible sign of temperature change until the pump is in the tens of Kelvin range. On these pumps, the pump pressure should be monitored for indications that the pump pressure is dropping and that this pressure drop occurs within a few tens of minutes. Once temperature and/or pressure drop are confirmed, one need simply wait for the pump to achieve nominal operating temperature. This should usually occur in 2-3 hours.
##'''Place Pump in Service'''. Once the pump has achieved nominal operating temperature, verify that the chamber pressure is below 30 mTorr (the lower the better) and then open the gate valve. Verify that the chamber pressure drops rapidly. Monitor the pump pressure for the next few tens of minutes to ensure the cryopump doesn't crash (become overwhelmed and warm up).
##'''Paperwork'''. If there exists a tag on the cryopump, mark the date and the fact that regeneration was performed for future reference.
#'''Cold Head Purge'''. This involves removing contaminant gases from the cold head. During normal operation, gases other than helium will tend to freeze withing the cold head's (pump's) helium circuit and impair operations. If allowed to build too much, this ice can mechanically damage components in the cold head. Similar to regeneration, the pump is stopped and the cold head is disconnected quickly from the compressor. Once warm, the thawed contaminant gases are purged from the cold head's helium circuit. Cold head purge require implicit regeneration of the cryopanels.
#'''Compressor Purge'''. When contaminant gases are significant, it can be necessary to purge the compressor as well. Compressor Purges require implicit Cold Head Purge and Cryopanel Regeneration.
#'''Adsorber Change'''. This is a scheduled, preventive maintenance action, typically performed annually. The adorber is basically an oil filter that prevents compressor oil from entering the cold head. Failure to perform this maintenance on schedule will result in contamination and failure of the cold head and necessitate a costly rebuild. Adsorber changes require implicit Cryopanel Regeneration, and usually include Cold Head Purges as well.

=== Diffusion Pump Based Stations (rare) ===

The Diffusion Pump Based Vacuum Station is a system used to produce high vacuum (10-6 < X < 10-9 Torr ) in some specialized systems within the laboratory, notably the SNICS source and one of the target lab evaporators. Diffusion pumps, in general, are being replaced by more modern alternatives and are typically no longer included in new designs. Feel free to skip this section if you're short on time. Diffusion pump systems are ''throughput'' systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Diffusion pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the diffusion pump's discharge port and atmosphere. In our lab, this roughing pump is an oil-sealed, rotary-vane vacuum pump.

The standard diffusion pump station consists of the following components:
* A single diffusion pump.
* A single roughing pump.
* An electro-pneumatically or manually operated, high-throughput, gate valve.
* An electro-pneumatically or manually operated foreline valve.
* A foreline vacuum pump gauge
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit. (on some systems)
* A panel-mounted indicator & control panel. (on some systems)
* A source of water cooling.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the diffusion pump and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the diffusion pump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the diffusion pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the diffusion pump is at its operating temperature and has water cooling''' and that the foreline pressure is good ( < 50 mTorr ). If a refrigerated baffle or cryotrap is installed, verify that it is functional and/or filled and thus cold.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below 300 millitor and quickly recover. If the foreline pressure fails to start dropping within a minute, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a diffusion pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Monitor foreline pressure until back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the diffusion pump's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the diffusion pump is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.
Diffusion pumps are surprisingly maintenance free. Occasional oil changes are needed when the oil becomes contaminated, or fractionates beyond tolerance. Sufficient cooling water flow and temperatures must be maintained at all times when the pump is running. The cal-rod or plate heater can fail, as can the high-temperature wiring components. The Klixon thermal safety switch can fail. Loss of cooling water in combination with a Klixon safety switch failure can result in severe to catastrophic damage. Trust me. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Standard Laboratory Vacuum System Stations

2026-02-09T14:03:07Z

Pbarber: /* Operation */

== Standard Laboratory Vacuum System Stations ==
=== Introduction ===
In order to achieve high vacuum (nominally ~ 1 x 10E-6 Torr) it is necessary to combine various vacuum technology components into a system, sometimes colloquially referred to as a "stack." Throughout our lab, there are vacuum stations that are used to achieve high vacuum in different sections of the accelerator. Typically, anywhere the beamlines or accelerator can be separated by isolation valves, a station exists between those valves. It is undesirable to have a "dead section" of beamline - a section that is isolated by valves but without a vacuum station. This page explains the basic stacks or systems in used at each station throughout our lab.
=== Turbo-Pump Based Stations ===
The Turbo-Pump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Turbo pump, or more exactingly turbomolecular pump, systems are ''throughput'' pumping systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Turbo pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the turbo's discharge port and atmosphere. In our lab, this roughing pump is typically an oil-sealed, rotary-vane vacuum pump but may sometimes be an oil-free, dry scroll pump.

The standard turbo pump station consists of the following components:
* A single turbomolecular vacuum pump.
* A single roughing pump.
* An electro-pneumatically operated, high-throughput, gate valve.
* A hand operated (usually) or an electro-pneumatically operated (rarely) foreline valve.
* A molecular-sieve foreline trap.
* A foreline vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the turbo and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the turbo inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the turbo pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the turbo is in NORMAL OPERATION (running at full speed)''' and that the foreline pressure is good ( < 50 mTorr ). Some of our turbos have a LOW SPEED setting that can be employed when not in use to prolong bearing life. The turbo should be brought to full speed before placing online.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below a few hundred millitor and quickly recover. Danger to the turbo can occur if the foreline remains well above 50 mTorr for a prolonged period (10's of minutes). Prolonged exposures to high foreline pressures will cause bearing overheating and pump shut-down. Never walk off and leave a turbo running w/ high foreline pressures. If the foreline pressure fails to start dropping within a few minutes, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a turbo pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Be mindful of turbo pump temperature and foreline pressure until both are back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the turbo's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the turbo is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.
*'''MagLev Crash''': A rapid gas inrush in a magnetically levitated turbo can overwhelm the magnetic field bearings and cause the turbo to "sit down" on it's emergency bearings. When this occurs the turbo will "scream" loudly and can easily startle nearby personnel. MagLev crashes should be avoided if at all possible. Most maglev turbos have a limited number of times that this may occur before the emergency bearings must be replaced at significant cost.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

All of the turbo pumps in operation in our lab use one of two bearing types: (1) static or dynamic magnetic bearings, or (2) permanently lubricated ceramic ball bearings. In both of these cases, the pumps are run until failure. Some of our turbos have a hybrid bearing technology where one bearing is magnetic, but the other is ceramic ball. The Re-Buncher turbo does have a battery that must be replaced periodically. Cooling fan operation must be maintained when in operation unless approved by staff. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

=== Cryopump Based Stations ===
The Cryopump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Cryopumps are ''capture'' pumps, which means that the gases that are removed from the evacuated space are stored within the pump until the pump's capacity is reached. These gases must then be expelled through a process known as regeneration. Modern cryopumps can do this automatically. Sadly, our cryopumps are not modern cryopumps and regeneration must be done manually.

The standard cryopump station consists of the following components:
* A single cryopump.
* A single cryopump compressor.
* An electro-pneumatically operated, high-throughput, gate valve.
* A pump-mounted vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
A cryopump is a capture pump and will run continuously until one of the following occurs:
#Operation is interrupted long enough to allow the pump to warm and break its vacuum insulation
#Pump capacity is reached.
#Pump Failure occurs.

In a cryopump based vacuum station, the cryopump runs 24/7 and captures gas from the chamber by cryo-condensation and cryo-adsorption. If lab operations dictate that the beamline or chamber be vented, then the cryopump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 30 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the cryopump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 30 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the cryopump is cold''' (< ~ 25K) and that the pump pressure is low (< ~ 10 mTorr).
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the chamber/beamline pressure''' and ensure that it begins to fall. This should occur rapidly, as our standard cryopump provides a very high pumping speed for water vapor and nitrogen - the predominant gases in atmosphere. Check periodically to ensure that the system achieves a nominal pressure and the pump temperature remains nominal.

'''CAUTIONS'''
*Opening the cryopump when the chamber pressure is too high can cause the cryopump to "crash" or warm up beyond recovery.
*When warming, cryopumps can overpressure. All cryopumps have a pressure relief device of some kind, typically a spring-loaded, elastomer-sealed valve.
{{ Warning | The LE Tandem, HE Tandem, and TR1 Analyzing Magnet cryopump pressure relief valves have been modified with a relief valve capture device. This device encases the relief valve and directs any gas from it through a red polyethylene tube to the Tritium Source fume hood. DO NOT alter, modify, or otherwise disturb this system without speaking to the Tritium Source team. }}
Cryopumps designed for ultra-high vacuum systems may also have a single-use burst disk which ruptures violently when actuated. (none of our cryopumps have burst disks)
*When warming, the external cryopanel housing can become so cold that it condenses water vapor and can create a drip hazard for equipment located below it.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

Maintenance actions involving cryopumps almost always involve thermal cycling and therefore can involve prolonged periods of time. It is not uncommon to lose the better part of a day of data collection due to a cryopump issue.

Common cryopump maintenance actions include:
#'''Regeneration'''. This is the process of ridding the pump of the captured gas. Regeneration is needed when the pump reaches capacity or develops a cold short--an ice bridge between the interior cryopanels and exterior housing which prevents the pump from achieving it's operating temperature. Regeneration requires thermal cycling. Typically regeneration is performed by staff during normal business hours. All other maintenance actions will require regeneration as part of the maintenance action. The following procedure for regeneration is provided in case those unfamiliar with the process are required to perform it to restore operations.
##'''Isolate the cryopump''' from the vacuum chamber or beamline by shutting the gate valve. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve.
##'''Turn off the cryopump compressor'''.
##'''Vent the cryopump'''. Locate a source of dry nitrogen, if possible, and use this to vent the cryopump. Allow the cryopump to come to atmospheric pressure. Use caution when connecting the dry nitrogen source and ensure that the pump is never over-pressured.
##'''Open the relief valve'''. Carefully pull the relief valve open and place something relatively soft in the elastomer seal to prevent closure. A wooden cotton swab handle or a nylon tie-wrap works well.
##'''Start Dry Nitrogen Bleed'''. Establish a slow-flow from the dry nitrogen line and connect it to the pump-out valve so that a small amount of dry nitrogen flows through the pump and out of the relief valve.
##'''Start the Heater'''. If one exist, initiate heating on the housing. This is typically done w/ a silicone heat-tape wrapped around the pump housing. '''CAUTION''': Be sure to follow any instructions on the heater control. Over heating the pump can melt the indium components!
##'''Monitor the pump temperature'''. Allow the pump to come to room temperature, or slightly above. Some of our pumps have silicon diode thermometry and will read the temperature fairly well throughout the range to ambient. Other pumps have hydrogen vapor pressure thermometry and do not accurately read the temperature above the low Kelvin range. Allow these pumps to warm/flow for '''at least''' two hours, and up to four if possible.
##'''Stop Dry Nitrogen Flow'''. Once the pump has reached ambient temperature or slightly above, stop the flow of nitrogen. Remove the nitrogen source connection. Remove the device that was used to hold the relief valve open and visually confirm that it closes properly.
##'''Turn Off Heating'''. If a heater was used to warm the pump during flow, turn it off now.
##'''Pump out the Cryopanels'''. Connect an oil-free pumping cart to the cryopump and initate pumping. It can take a while to pump out a cryopump, but if the pump was fully warmed and flowed, it should be done in less than two hours.
##'''Test the Pump Out'''. Verify that the pump is fully evacuated by ensuring the following criteria: (1) pump pressure is 30 mTorr or less, and (2) the pressure in the pump has a rate of rise < 15 mTorr/min when the roughing cart is isolated from the pump. If these criteria are met, re-open the valve to the scroll cart and proceed to the next step.
##'''Restart the Cryopump'''. Using the switch on the compressor, restart the cryopump and allow it to run.
##'''Stop the Pump Out'''. Within about 10 mins of starting the compressor, shut the valve to isolate the scroll cart.
##'''Monitor the Pump'''. On pumps with silicon diode thermometry, one need only monitor the temperature display and verify that the pump is cooling down. On pumps with hydrogen vapor bulb thermometry, there will be no visible sign of temperature change until the pump is in the tens of Kelvin range. On these pumps, the pump pressure should be monitored for indications that the pump pressure is dropping and that this pressure drop occurs within a few tens of minutes. Once temperature and/or pressure drop are confirmed, one need simply wait for the pump to achieve nominal operating temperature. This should usually occur in 2-3 hours.
##'''Place Pump in Service'''. Once the pump has achieved nominal operating temperature, verify that the chamber pressure is below 30 mTorr (the lower the better) and then open the gate valve. Verify that the chamber pressure drops rapidly. Monitor the pump pressure for the next few tens of minutes to ensure the cryopump doesn't crash (become overwhelmed and warm up).
##'''Paperwork'''. If there exists a tag on the cryopump, mark the date and the fact that regeneration was performed for future reference.
#'''Cold Head Purge'''. This involves removing contaminant gases from the cold head. During normal operation, gases other than helium will tend to freeze withing the cold head's (pump's) helium circuit and impair operations. If allowed to build too much, this ice can mechanically damage components in the cold head. Similar to regeneration, the pump is stopped and the cold head is disconnected quickly from the compressor. Once warm, the thawed contaminant gases are purged from the cold head's helium circuit. Cold head purge require implicit regeneration of the cryopanels.
#'''Compressor Purge'''. When contaminant gases are significant, it can be necessary to purge the compressor as well. Compressor Purges require implicit Cold Head Purge and Cryopanel Regeneration.
#'''Adsorber Change'''. This is a scheduled, preventive maintenance action, typically performed annually. The adorber is basically an oil filter that prevents compressor oil from entering the cold head. Failure to perform this maintenance on schedule will result in contamination and failure of the cold head and necessitate a costly rebuild. Adsorber changes require implicit Cryopanel Regeneration, and usually include Cold Head Purges as well.

=== Diffusion Pump Based Stations (rare) ===

The Diffusion Pump Based Vacuum Station is a system used to produce high vacuum (10-6 < X < 10-9 Torr ) in some specialized systems within the laboratory, notably the SNICS source and one of the target lab evaporators. Diffusion pumps, in general, are being replaced by more modern alternatives and are typically no longer included in new designs. Feel free to skip this section if you're short on time. Diffusion pump systems are ''throughput'' systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Diffusion pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the diffusion pump's discharge port and atmosphere. In our lab, this roughing pump is an oil-sealed, rotary-vane vacuum pump.

The standard diffusion pump station consists of the following components:
* A single diffusion pump.
* A single roughing pump.
* An electro-pneumatically or manually operated, high-throughput, gate valve.
* An electro-pneumatically or manually operated foreline valve.
* A foreline vacuum pump gauge
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit. (on some systems)
* A panel-mounted indicator & control panel. (on some systems)
* A source of water cooling.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the diffusion pump and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the diffusion pump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the diffusion pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the diffusion pump is at its operating temperature and has water cooling''' and that the foreline pressure is good ( < 50 mTorr ). If a refrigerated baffle or cryotrap is installed, verify that it is functional and/or filled and thus cold.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below 300 millitor and quickly recover. If the foreline pressure fails to start dropping within a minute, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a diffusion pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Monitor foreline pressure until back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the diffusion pump's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the diffusion pump is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.
Diffusion pumps are surprisingly maintenance free. Occasional oil changes are needed when the oil becomes contaminated, or fractionates beyond tolerance. Sufficient cooling water flow and temperatures must be maintained at all times when the pump is running. The cal-rod or plate heater can fail, as can the high-temperature wiring components. The Klixon thermal safety switch can fail. Loss of cooling water in combination with a Klixon safety switch failure can result in severe to catastrophic damage. Trust me. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Standard Laboratory Vacuum System Stations

2026-02-09T14:02:15Z

Pbarber: /* Operation */

== Standard Laboratory Vacuum System Stations ==
=== Introduction ===
In order to achieve high vacuum (nominally ~ 1 x 10E-6 Torr) it is necessary to combine various vacuum technology components into a system, sometimes colloquially referred to as a "stack." Throughout our lab, there are vacuum stations that are used to achieve high vacuum in different sections of the accelerator. Typically, anywhere the beamlines or accelerator can be separated by isolation valves, a station exists between those valves. It is undesirable to have a "dead section" of beamline - a section that is isolated by valves but without a vacuum station. This page explains the basic stacks or systems in used at each station throughout our lab.
=== Turbo-Pump Based Stations ===
The Turbo-Pump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Turbo pump, or more exactingly turbomolecular pump, systems are ''throughput'' pumping systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Turbo pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the turbo's discharge port and atmosphere. In our lab, this roughing pump is typically an oil-sealed, rotary-vane vacuum pump but may sometimes be an oil-free, dry scroll pump.

The standard turbo pump station consists of the following components:
* A single turbomolecular vacuum pump.
* A single roughing pump.
* An electro-pneumatically operated, high-throughput, gate valve.
* A hand operated (usually) or an electro-pneumatically operated (rarely) foreline valve.
* A molecular-sieve foreline trap.
* A foreline vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the turbo and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the turbo inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the turbo pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the turbo is in NORMAL OPERATION (running at full speed)''' and that the foreline pressure is good ( < 50 mTorr ). Some of our turbos have a LOW SPEED setting that can be employed when not in use to prolong bearing life. The turbo should be brought to full speed before placing online.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below a few hundred millitor and quickly recover. Danger to the turbo can occur if the foreline remains well above 50 mTorr for a prolonged period (10's of minutes). Prolonged exposures to high foreline pressures will cause bearing overheating and pump shut-down. Never walk off and leave a turbo running w/ high foreline pressures. If the foreline pressure fails to start dropping within a few minutes, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a turbo pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Be mindful of turbo pump temperature and foreline pressure until both are back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the turbo's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the turbo is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.
*'''MagLev Crash''': A rapid gas inrush in a magnetically levitated turbo can overwhelm the magnetic field bearings and cause the turbo to "sit down" on it's emergency bearings. When this occurs the turbo will "scream" loudly and can easily startle nearby personnel. MagLev crashes should be avoided if at all possible. Most maglev turbos have a limited number of times that this may occur before the emergency bearings must be replaced at significant cost.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

All of the turbo pumps in operation in our lab use one of two bearing types: (1) static or dynamic magnetic bearings, or (2) permanently lubricated ceramic ball bearings. In both of these cases, the pumps are run until failure. Some of our turbos have a hybrid bearing technology where one bearing is magnetic, but the other is ceramic ball. The Re-Buncher turbo does have a battery that must be replaced periodically. Cooling fan operation must be maintained when in operation unless approved by staff. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

=== Cryopump Based Stations ===
The Cryopump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Cryopumps are ''capture'' pumps, which means that the gases that are removed from the evacuated space are stored within the pump until the pump's capacity is reached. These gases must then be expelled through a process known as regeneration. Modern cryopumps can do this automatically. Sadly, our cryopumps are not modern cryopumps and regeneration must be done manually.

The standard cryopump station consists of the following components:
* A single cryopump.
* A single cryopump compressor.
* An electro-pneumatically operated, high-throughput, gate valve.
* A pump-mounted vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
A cryopump is a capture pump and will run continuously until one of the following occurs:
#Operation is interrupted long enough to allow the pump to warm and break its vacuum insulation
#Pump capacity is reached.
#Pump Failure occurs.

In a cryopump based vacuum station, the cryopump runs 24/7 and captures gas from the chamber by cryo-condensation and cryo-adsorption. If lab operations dictate that the beamline or chamber be vented, then the cryopump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 30 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the cryopump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 30 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the cryopump is cold''' (< ~ 25K) and that the pump pressure is low (< ~ 10 mTorr).
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the chamber/beamline pressure''' and ensure that it begins to fall. This should occur rapidly, as our standard cryopump provides a very high pumping speed for water vapor and nitrogen - the predominant gases in atmosphere. Check periodically to ensure that the system achieves a nominal pressure and the pump temperature remains nominal.

'''CAUTIONS'''
*Opening the cryopump when the chamber pressure is too high can cause the cryopump to "crash" or warm up beyond recovery.
*When warming, cryopumps can overpressure. All cryopumps have a pressure relief device of some kind, typically a spring-loaded, elastomer-sealed valve.
{{ Warning | The LE Tandem, HE Tandem, and TR1 Analyzing Magnet cryopump pressure relief valves have been modified with a relief valve capture device. This device encases the relief valve and directs any gas from it through a red polyethylene tube to the Tritium Source fume hood. DO NOT alter, modify, or otherwise disturb this system without speaking to the Tritium Source team. }}

Cryopumps designed for ultra-high vacuum systems may also have a single-use burst disk which ruptures violently when actuated. (none of our cryopumps have burst disks)
*When warming, the external cryopanel housing can become so cold that it condenses water vapor and can create a drip hazard for equipment located below it.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

Maintenance actions involving cryopumps almost always involve thermal cycling and therefore can involve prolonged periods of time. It is not uncommon to lose the better part of a day of data collection due to a cryopump issue.

Common cryopump maintenance actions include:
#'''Regeneration'''. This is the process of ridding the pump of the captured gas. Regeneration is needed when the pump reaches capacity or develops a cold short--an ice bridge between the interior cryopanels and exterior housing which prevents the pump from achieving it's operating temperature. Regeneration requires thermal cycling. Typically regeneration is performed by staff during normal business hours. All other maintenance actions will require regeneration as part of the maintenance action. The following procedure for regeneration is provided in case those unfamiliar with the process are required to perform it to restore operations.
##'''Isolate the cryopump''' from the vacuum chamber or beamline by shutting the gate valve. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve.
##'''Turn off the cryopump compressor'''.
##'''Vent the cryopump'''. Locate a source of dry nitrogen, if possible, and use this to vent the cryopump. Allow the cryopump to come to atmospheric pressure. Use caution when connecting the dry nitrogen source and ensure that the pump is never over-pressured.
##'''Open the relief valve'''. Carefully pull the relief valve open and place something relatively soft in the elastomer seal to prevent closure. A wooden cotton swab handle or a nylon tie-wrap works well.
##'''Start Dry Nitrogen Bleed'''. Establish a slow-flow from the dry nitrogen line and connect it to the pump-out valve so that a small amount of dry nitrogen flows through the pump and out of the relief valve.
##'''Start the Heater'''. If one exist, initiate heating on the housing. This is typically done w/ a silicone heat-tape wrapped around the pump housing. '''CAUTION''': Be sure to follow any instructions on the heater control. Over heating the pump can melt the indium components!
##'''Monitor the pump temperature'''. Allow the pump to come to room temperature, or slightly above. Some of our pumps have silicon diode thermometry and will read the temperature fairly well throughout the range to ambient. Other pumps have hydrogen vapor pressure thermometry and do not accurately read the temperature above the low Kelvin range. Allow these pumps to warm/flow for '''at least''' two hours, and up to four if possible.
##'''Stop Dry Nitrogen Flow'''. Once the pump has reached ambient temperature or slightly above, stop the flow of nitrogen. Remove the nitrogen source connection. Remove the device that was used to hold the relief valve open and visually confirm that it closes properly.
##'''Turn Off Heating'''. If a heater was used to warm the pump during flow, turn it off now.
##'''Pump out the Cryopanels'''. Connect an oil-free pumping cart to the cryopump and initate pumping. It can take a while to pump out a cryopump, but if the pump was fully warmed and flowed, it should be done in less than two hours.
##'''Test the Pump Out'''. Verify that the pump is fully evacuated by ensuring the following criteria: (1) pump pressure is 30 mTorr or less, and (2) the pressure in the pump has a rate of rise < 15 mTorr/min when the roughing cart is isolated from the pump. If these criteria are met, re-open the valve to the scroll cart and proceed to the next step.
##'''Restart the Cryopump'''. Using the switch on the compressor, restart the cryopump and allow it to run.
##'''Stop the Pump Out'''. Within about 10 mins of starting the compressor, shut the valve to isolate the scroll cart.
##'''Monitor the Pump'''. On pumps with silicon diode thermometry, one need only monitor the temperature display and verify that the pump is cooling down. On pumps with hydrogen vapor bulb thermometry, there will be no visible sign of temperature change until the pump is in the tens of Kelvin range. On these pumps, the pump pressure should be monitored for indications that the pump pressure is dropping and that this pressure drop occurs within a few tens of minutes. Once temperature and/or pressure drop are confirmed, one need simply wait for the pump to achieve nominal operating temperature. This should usually occur in 2-3 hours.
##'''Place Pump in Service'''. Once the pump has achieved nominal operating temperature, verify that the chamber pressure is below 30 mTorr (the lower the better) and then open the gate valve. Verify that the chamber pressure drops rapidly. Monitor the pump pressure for the next few tens of minutes to ensure the cryopump doesn't crash (become overwhelmed and warm up).
##'''Paperwork'''. If there exists a tag on the cryopump, mark the date and the fact that regeneration was performed for future reference.
#'''Cold Head Purge'''. This involves removing contaminant gases from the cold head. During normal operation, gases other than helium will tend to freeze withing the cold head's (pump's) helium circuit and impair operations. If allowed to build too much, this ice can mechanically damage components in the cold head. Similar to regeneration, the pump is stopped and the cold head is disconnected quickly from the compressor. Once warm, the thawed contaminant gases are purged from the cold head's helium circuit. Cold head purge require implicit regeneration of the cryopanels.
#'''Compressor Purge'''. When contaminant gases are significant, it can be necessary to purge the compressor as well. Compressor Purges require implicit Cold Head Purge and Cryopanel Regeneration.
#'''Adsorber Change'''. This is a scheduled, preventive maintenance action, typically performed annually. The adorber is basically an oil filter that prevents compressor oil from entering the cold head. Failure to perform this maintenance on schedule will result in contamination and failure of the cold head and necessitate a costly rebuild. Adsorber changes require implicit Cryopanel Regeneration, and usually include Cold Head Purges as well.

=== Diffusion Pump Based Stations (rare) ===

The Diffusion Pump Based Vacuum Station is a system used to produce high vacuum (10-6 < X < 10-9 Torr ) in some specialized systems within the laboratory, notably the SNICS source and one of the target lab evaporators. Diffusion pumps, in general, are being replaced by more modern alternatives and are typically no longer included in new designs. Feel free to skip this section if you're short on time. Diffusion pump systems are ''throughput'' systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Diffusion pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the diffusion pump's discharge port and atmosphere. In our lab, this roughing pump is an oil-sealed, rotary-vane vacuum pump.

The standard diffusion pump station consists of the following components:
* A single diffusion pump.
* A single roughing pump.
* An electro-pneumatically or manually operated, high-throughput, gate valve.
* An electro-pneumatically or manually operated foreline valve.
* A foreline vacuum pump gauge
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit. (on some systems)
* A panel-mounted indicator & control panel. (on some systems)
* A source of water cooling.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the diffusion pump and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the diffusion pump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the diffusion pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the diffusion pump is at its operating temperature and has water cooling''' and that the foreline pressure is good ( < 50 mTorr ). If a refrigerated baffle or cryotrap is installed, verify that it is functional and/or filled and thus cold.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below 300 millitor and quickly recover. If the foreline pressure fails to start dropping within a minute, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a diffusion pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Monitor foreline pressure until back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the diffusion pump's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the diffusion pump is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.
Diffusion pumps are surprisingly maintenance free. Occasional oil changes are needed when the oil becomes contaminated, or fractionates beyond tolerance. Sufficient cooling water flow and temperatures must be maintained at all times when the pump is running. The cal-rod or plate heater can fail, as can the high-temperature wiring components. The Klixon thermal safety switch can fail. Loss of cooling water in combination with a Klixon safety switch failure can result in severe to catastrophic damage. Trust me. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T20:43:41Z

Pbarber: /* Fault Indication and Assessment */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC, the offending sensor is recorded, and the system will enter fault mode. All of the beamline isolation valves will immediately shut, with the exception of the SNICS Source exit valve. This valve remains open to sustain pumping on the source inflector magnet section, unless the SNICS Source sensor originates the fault. In this case, the SNICS Source exit valve will shut also.

The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valves may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips, even if the failure has not been addressed yet.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to support useful troubleshooting, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As of this writing (05 Dec 2025), the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

TODO: I want to put the CURRENT program file here in both click and PDF formats.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. An Automation Direct QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond [https://www.newark.com/hammond/513-0900/enclosure-instrument-steel-gray/dp/73J4427 513-0900] aluminum box.

Note to self: Include the VCP bill of materials here somewhere.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T20:15:04Z

Pbarber: /* PLC */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As of this writing (05 Dec 2025), the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

TODO: I want to put the CURRENT program file here in both click and PDF formats.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. An Automation Direct QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond [https://www.newark.com/hammond/513-0900/enclosure-instrument-steel-gray/dp/73J4427 513-0900] aluminum box.

Note to self: Include the VCP bill of materials here somewhere.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T20:13:52Z

Pbarber: /* VCP */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As 05 Dec 2025, the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

TODO: I want to put the CURRENT program file here in both click and PDF formats.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. An Automation Direct QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond [https://www.newark.com/hammond/513-0900/enclosure-instrument-steel-gray/dp/73J4427 513-0900] aluminum box.

Note to self: Include the VCP bill of materials here somewhere.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T16:07:04Z

Pbarber: /* VCP */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As 05 Dec 2025, the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

TODO: I want to put the CURRENT program file here in both click and PDF formats.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC. A QM2X1-D24 relay is used for energizing the gate valve solenoid valve. Back panel connectors are Molex, and the entire assembly is housed in a Hammond 513-0900 aluminum box.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T15:56:58Z

Pbarber: /* VCP */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As 05 Dec 2025, the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

TODO: I want to put the CURRENT program file here in both click and PDF formats.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP uses indicators and combination switch/indicators manufactured by IDEC.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T15:55:12Z

Pbarber: /* PLC */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare.

{{ Notice | As 05 Dec 2025, the QM2X1-D24 Relay had been DISCONTINUED, WITHOUT REPLACEMENT. The MCP uses one of these relays for the PELOTRON interface and each VCP uses one of these relays for valve control.}}

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

TODO: I want to put the CURRENT program file here in both click and PDF formats.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP contains switches manufactured by

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T15:49:56Z

Pbarber: /* Basic Hardware */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare. DISCONTINUED, WITHOUT REPLACEMENT

===PLC Programming===
Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

TODO: I want to put the CURRENT program file here in both click and PDF formats.

===VCP===
There is a Valve Control Panel (VCP) associated with each valve. The VCP interfaces directly with the MCP and the valve directly. All VCPs are identical and can be interchanged. The logic associated with the directionality of the sensors is actually accomplished via the wiring between the VCP and the MCP and can not be changed easily. This is why some VCPs will have the upstream sensor on the left, while other VCPs will have the upstream sensor on the right. Re-orientation of the VCP's face direction cannot be done w/o changing the wiring of the system.

The VCP contains switches manufactured by

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T14:47:01Z

Pbarber: /* PLC */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare. DISCONTINUED, WITHOUT REPLACEMENT

Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct]. The PLC is programmed using ladder logic w/ a few advanced features such as timers, clocks, etc. The program is heavily commented in the hope that whoever follows will understand it with as little difficulty as possible.

I want to put the CURRENT program file here in both click and PDF formats.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T14:43:25Z

Pbarber: /* Basic Hardware */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* CLICK Digital Input Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16td1 C0-16TD1], Quantity 3 used, Quantity 1 spare
* CLICK Digital Output Module, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/stackable_i-z-o_modules/c0-16nd3 C0-16ND3], Quantity 3 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare. DISCONTINUED, WITHOUT REPLACEMENT

Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct].

I want to put the CURRENT program file here in both click and PDF formats.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T14:13:42Z

Pbarber: /* PLC */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D], preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC], Quantity 1 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare. DISCONTINUED, WITHOUT REPLACEMENT

Programming of the CLICK PLC is accomplished using [https://www.automationdirect.com/clickplcs/free-software/free-click-software freely available software] from [https://www.automationdirect.com Automation Direct].

I want to put the CURRENT program file here in both click and PDF formats.

Tandem Beamline Isolation (Fast Valve) System

2025-12-05T14:05:38Z

Pbarber: /* Basic Hardware */

= Introduction =

The Tandem Beamline Isolation System, historically referred to as the Fast Valve System, is now a PLC controlled vacuum valve interlock system. It is designed to quickly respond to vacuum failures by isolating the accelerator beamline sections and preventing the failure from propagating further. This system also interlocks with the Pelletron to shut down operation when vacuum faults are detected in the vacuum proximal to the accelerator tubes. Each of the six valves controlled has a corresponding valve control panel (VCP) which allows the valve to be configured for operation and/or maintenance activities. All user operation occurs through these valve control panels.

== Photos ==

<gallery>
FV mcp.jpeg|Master Control Panel
FV vcp.jpeg|High Energy Valve Control Panel
FV ctrl rm display.jpeg|Control Room Valve Status Display Panel
FV func blk diag.jpeg|Functional Block Diagram
FV vcp graphic.jpg|Rendered CAD graphic of VCP Front Panel
</gallery>

= Operation =

All operator actions are performed through the Valve Control Panels (VCPs). Refer to the [[:File:FV vcp graphic.jpg|VCP front panel graphic]] for reference while reading this section. There are no operator actions available at the Master Control Panel (MCP).

The valve control panel is always located near the associated valve. The front panel is divided into three sections; LEFT, MIDDLE, and RIGHT. Note the small vertical lines marking these divisions. You may think of the MIDDLE section as representing the valve itself, and the LEFT and RIGHT sections as representing the vacuum sensors on the corresponding side of the valve.

== Sensor Indication and Control ==

Take a look at the left side of the VCP. At the top, there is a green lamp that reads GOOD. When lit, the pressure in the beamline is below, or better than, the set point threshold. Below that, there is a red lamp that reads BAD. When lit, the pressure in the beamline is above, or worse than, the set point threshold or the sensor is off or otherwise not functioning. The GOOD and BAD lamps should never be lit at the same time, with one exception covered later. The lowest indicator on the LEFT side is colored yellow and reads IGNORE. This is both a lamp AND a momentary contact switch. This switch is used for maintenance activities. Pressing this switch will cause the system to IGNORE the sensor on the corresponding side. While that sensor is being ignored, the yellow lamp will flash at a 1 second rate to remind operators that this sensor is being ignored. The RIGHT side lamps and switches function identically for the sensor on that side of the valve.

{{Notice | On the VCP, LEFT and RIGHT refer to the sensor direction from the valve - as viewed from the front panel - and have NO RELATIONSHIP to the idea of upstream and downstream beam reference.}}

While not immediately obvious, one should understand that the sensor that monitors that status of the vacuum in its section will display that status on 2 or 3 different valve control panels. This is because the sensor monitors the section between 2 or three valves. Correspondingly, toggling the IGNORE function on one VCP will result in the IGNORE function being displayed on 2 or three VCPs, depending on the ignored sensor position. The only exception to this are the sensor stations on either side of the tandem. This is because there are actually two separate sensors (as well as pump stacks) between the low and high energy valves.

== Valve Indication and Control ==

Recall that the MIDDLE section of the VCP can be thought of as representing the valve. There are two combination lamp/switch assemblies. The green one is labeled OPEN/ACK while the RED one is labeled SHUT. When the valve is open, the top lamp will be lit GREEN, and when the valve is shut, the lower lamp will be lit RED.

If the valve is SHUT, and you wish to OPEN the valve, then one of two conditions must be met:
# The vacuum on both the LEFT and RIGHT must be good, with the GREEN lamp lit or,
# Any sensor that does not indicate a good vacuum must be in the IGNORE mode.

If the valve is OPEN, and you wish to SHUT the valve, simply press the switch marked SHUT. Shutting the valve is NEVER impeded for any reason.

{{Warning | Placing a sensor in IGNORE mode will allow valve operation without interlock protection from that sensor. When both sides of the VCP are in ignore mode, the valve operation is not impeded in any way. If you are not confident that it is safe to IGNORE a sensor, or to operate a valve while a sensor is in IGNORE mode, please contact staff.}}

Valve status is also duplicated on the [[:File:FV ctrl rm display.jpeg|Control Room Display Panel]] for operator convenience.

== Fault Indication and Assessment ==

When a Tandem vacuum system fault occurs, one of the sensors will detect it and make a transition from GOOD to BAD. This transition is detected by the PLC and the system will enter fault mode. Most of the beamline isolation valves will immediately shut. The Tandem operator must then survey each vacuum station and determine the cause of the fault. Once the cause of the fault is identified, corrected, and the vacuum status restored, the valve may be reopened. Other valves in the system, with good vacuum on each side may be opened at any time after the system trips.

Occasionally, a transient condition may generate a fault. This occurs when a vacuum sensor makes a GODD to BAD transition, which trips the system, but then transitions from BAD to GOOD before an operator can identify the cause. In order to prevent this situation, the PLC is programmed to "remember" which station caused the fault. Should the offending sensor transition back to GOOD, the PLC will indicate that the vacuum is GOOD by lighting the green lamp, but will flash the red BAD lamp at a 0.5 sec rate to indicate which sensor caused the fault. When this occurs, before the valve can be opened, one must "acknowledge" the transient indicator by pressing the OPEN/ACK switch. This will stop the BAD lamp from flashing and reset the PLC transient tracking system. The valve may now be opened by the OPEN/ACK switch as usual.

== Fault Integration with Tandem Pelletron ==

If the fault occurs in the Tandem's High Energy or Low Energy vacuum station, the Pelletron Interlock will trip. This is automatically re-enabled after 1 minute if the vacuum in both of these stations are restored. Vacuum faults in other stations will not trip the Pelletron. Note that the IGNORE toggle will not permit Pelletron operation. The vacuum sensor MUST indicate GOOD vacuum in order for the Pelletron interlock to be satisfied. Bypassing the sensor with a prepared shorting connector is possible for emergency operation, but provides no protection whatsoever and should only be done with laboratory management approval.

= Technical Description and Troubleshooting =

'''Unfinished...'''

This section is intended for those who need to troubleshoot, modify, or repair the system.

== Basic Hardware ==
The Tandem Beamline Isolation (Fast Valve) System uses a programmable logic controller (PLC) to perform command and control of the entire system. All inputs to and outputs from the PLC are digital I/O (DIO) signals using 24VDC logic levels. The PLC takes inputs from the vacuum sensors and from switches in the Valve Control Panels (VCPs) and provides outputs to the VCPs and the control room Valve Status Panel.

=== PLC ===
The PLC used is the CLICK Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plcs_(stackable_micro_brick)/plc_units/c0-01dd1-d C0-01DD1-D] from [https://www.automationdirect.com Automation Direct]. Power for the PLC and it's associated DIO modules is supplied by a CLICK power supply, Model # [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac CO-01AC] power supply. This power supply only supplies power for the internal logic operation of these modules. Power for all external devices, such as the VCP lights, switches, relays, etc., is supplied by a second 24 VDC power supply, Model # PSB24-060-P, originally available from [https://www.automationdirect.com Automation Direct]. The PLC, DIO moudles, and both power supplies are DIN rail mounted in the Master Control Panel (MCP).

As of this writing (05 Dec 2025) The PLC is still listed for sale at $153.00, the [https://www.automationdirect.com/adc/shopping/catalog/programmable_controllers/click_plus_plcs_(stackable_micro_modular)/power_supplies/c0-01ac Click power supply] at $73, and the auxiliary power supply (PSB24-060-P) has been retired, with the Model # [https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/dc_power_supplies/din_rail_mount/psb24-060s-p PSB24-060S-P] listed as the replacement at $55.00

Currently, the critical spares inventory contains the following items related to the MCP:
* CLICK PLC, Model # C0-10DD1-D, preprogrammed w/ software version 2, release 1, Quantity 1 used, Quantity 1 spare
* CLICK Power Supply, Model # C0-01AC, Quantity 1 used, Quantity 1 spare
* Power Supply, Model # PSB24-060-P, Quantity 1 used, Quantity 2 spare
* Relay, Model # QM2X1-D24, Quantity 1 used, Quantity 2 spare

Programming of the CLICK PLC is accomplished using freely available software from [https://www.automationdirect.com Automation Direct].

I want to put the CURRENT program file here in both click and PDF formats.

Tandem Beamline Isolation (Fast Valve) System

2025-12-04T17:45:14Z

Pbarber: /* Sensor Indication and Control */

Target Lab

2025-07-14T14:27:13Z

Pbarber: /* Pure Lithium Targets */

= NOTICE =

The Target Lab here at FoxLab has suffered significant atrophy since it was disassembled for asbestos removal. It has very limited capabilities at the moment. Planning is underway to restore it to its previous functionality. Information regarding current and future capabilities will be posted here as time permits.

= General Information =

== Target Frames ==
Standard target frames used here at FoxLab. CAD files for most of these frames are available. Use the contact link below to request them.
<gallery>
File:standard_fsu_tgt_frame.pdf|Original "standard" FSU Target Frame
File:Large fsu tgt frame.pdf|Large FSU Target Frame
File:Sps_fsu_tgt_frame_375.pdf|SPS (old Yale) target frame w/ 0.375" aperture
File:Sps_fsu_tgt_frame_500.PDF|SPS (old Yale) target frame w/ 0.500" aperture
File:Sps_x_fsu_tgt_frame.pdf|Adapter for mounting small FSU frame on SPS(old Yale) target ladder
File:Stripper_foil_frame.pdf|Tandem Terminal Stripper Foil Frame
File:External_2nd_stripper_frame.pdf|External 2nd Stripper Foil Frame
File:Clarion_tgt_frame.pdf|CLARION chamber target frame
</gallery>

= Current Capabilities =
== Pure Lithium Targets ==

One of the unique capabilities available here at FoxLab is the ability to produce pure pseudo-free-standing lithium targets. Lithium metal is evaporated onto a polyvinyl formal resin backing which burns away when placed in beam. These targets are transported under static vacuum from the evaporator to the experimental chamber.

Personnel requesting pure lithium targets should be aware of the following:
* Historically, these have only been manufactured on frames with a nominal 0.375" ( ~ 10 mm ) aperture. Requests for larger apertures will require technique development and success is not assured.
* The chamber in which the experiment will be performed must be capable of accepting one of the two vacuum target barrels available, or a new barrel must be designed/manufactured. As of this writing (15 Sep 2023) the original Yale SPS Chamber, the TR1 Scattering Chamber, the CATRiNA chamber and the newly installed SPS "Wild CeBrAs" chamber qualify.
* It is not uncommon for the polyvinyl formal backings to break during evaporation. It is best to have multiple backings on the target ladder to increase the odds of getting a usable target.
* The polyvinyl formal backing can contribute carbon, hydrogen, and oxygen until it burns away.
* 7Li (natural) and 6Li (enriched) can not be made at the same time. If you need both, two production runs have to be made separately.
* Typical lithium thickness ranges 50 to 250 ug/cm2.
* The lithium targets must be at the bottom of the target ladder.
* Multiple thicknesses are possible, but the thicker targets must be at the bottom of the target ladder.
* Production of pure lithium targets requires significant evaporator setup. For this reason, lithium targets are typically available for installation in the target chamber Tuesday - Friday, barring extraordinary circumstances.
* Post lithium target production requires significant evaporator clean up. Consequently, if the provided targets are destroyed due to vacuum accident or other misfortune, it can take a full day to recover and make another attempt.
* As long as high vacuum is maintained in the experimental chamber, experiments of over a week in duration are possible on a set of targets.

== Carbon ==
Carbon foils are made by carbon arc evaporation. Foils of 10, 20, 30, 50, 100, 150, 200, and 250 ug/cm2 are currently available on the small, "standard" FSU target frames. 50 and 100 ug/cm2 foils are available on slides and can be mounted on any frame upon request. If your experiment will tolerate it, these can be folded over the frame to produce double thickness, achieving 200 ug/cm2 as well. Other thickness will be made in future.

Carbon stripper foils for the Tandem are also manufactured by carbon arc evaporation. These are foils of nominal 200 Angstroms thick and are coated with collodion to facilitate handling during installation. A carbon stripper foil frame has two apertures. The Tandem holds nominally 300 frames, thus providing 600 foil positions. Students are sometimes called upon to mount foils on the frames and/or install the frames in the Tandem.

== Limited Low Melting Point Material Targets ==
Source materials with melting points below about 800 degrees C can be evaporated currently using resistive heating. Other materials with higher melting points can also be used if their vapor pressures at these temperatures are high enough. Targets made with these materials on carbon backings are relatively straightforward at the moment. Self-supporting targets made with these materials ''may'' be possible as well. Requests for these types of targets should be made early and discussed with the targetmaker before assuming they are available.

== CD2 Targets ==
Deuterated Polyethylene targets have been made here, but the techniques used have not yet produced high quality targets. While the capability exists here, more development work is required before these can be considered routine.

== Rolled Metal Targets ==
Very limited capabilities exist for rolled targets. Contact the targetmaker for details.

== Oxygen on Ta Backing ==
Manufactured through electrolysis using high-purity water. Isotopically enriched water can be used.

= Possible Future Capabilities =
* PID controlled substrate heating
* Electron beam evaporation
* In situ reduction-distillation evaporation
* Improved Target Storage Facility
* Improved Rolling capabilities
* Improved CD2 Production

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Target Lab

2025-02-12T16:33:05Z

Pbarber: /* Carbon */

= NOTICE =

The Target Lab here at FoxLab has suffered significant atrophy since it was disassembled for asbestos removal. It has very limited capabilities at the moment. Planning is underway to restore it to its previous functionality. Information regarding current and future capabilities will be posted here as time permits.

= General Information =

== Target Frames ==
Standard target frames used here at FoxLab. CAD files for most of these frames are available. Use the contact link below to request them.
<gallery>
File:standard_fsu_tgt_frame.pdf|Original "standard" FSU Target Frame
File:Large fsu tgt frame.pdf|Large FSU Target Frame
File:Sps_fsu_tgt_frame_375.pdf|SPS (old Yale) target frame w/ 0.375" aperture
File:Sps_fsu_tgt_frame_500.PDF|SPS (old Yale) target frame w/ 0.500" aperture
File:Sps_x_fsu_tgt_frame.pdf|Adapter for mounting small FSU frame on SPS(old Yale) target ladder
File:Stripper_foil_frame.pdf|Tandem Terminal Stripper Foil Frame
File:External_2nd_stripper_frame.pdf|External 2nd Stripper Foil Frame
File:Clarion_tgt_frame.pdf|CLARION chamber target frame
</gallery>

= Current Capabilities =
== Pure Lithium Targets ==

One of the unique capabilities available here at FoxLab is the ability to produce pure pseudo-free-standing lithium targets. Lithium metal is evaporated onto a polyvinyl formal resin backing which burns away when placed in beam. These targets are transported under static vacuum from the evaporator to the experimental chamber.

Personnel requesting pure lithium targets should be aware of the following:
* Historically, these have only been manufactured on frames with a nominal 0.375" ( ~ 10 mm ) aperture. Requests for larger apertures will require technique development and success is not assured.
* The chamber in which the experiment will be performed must be capable of accepting one of the two vacuum target barrels available, or a new barrel must be designed/manufactured. As of this writing (15 Sep 2023) the original Yale SPS Chamber, the TR1 Scattering Chamber, the CATRiNA chamber and the newly installed SPS "Wild CeBrAs" chamber qualify.
* It is not uncommon for the polyvinyl formal backings to break during evaporation. It is best to have multiple backings on the target ladder to increase the odds of getting a usable target.
* The polyvinyl formal backing can contribute carbon, hydrogen, and oxygen until it burns away.
* Isotopically enriched lithium is available.
* Typical lithium thickness ranges 50 to 250 ug/cm2.
* The lithium targets must be at the bottom of the target ladder.
* Multiple thicknesses are possible, but the thicker targets must be at the bottom of the target ladder.
* Production of pure lithium targets requires significant evaporator setup. For this reason, lithium targets are typically available for installation in the target chamber Tuesday - Friday, barring extraordinary circumstances.
* Post lithium target production requires significant evaporator clean up. Consequently, if the provided targets are destroyed due to vacuum accident or other misfortune, it can take a full day to recover and make another attempt.
* As long as high vacuum is maintained in the experimental chamber, experiments of over a week in duration are possible on a set of targets.

== Carbon ==
Carbon foils are made by carbon arc evaporation. Foils of 10, 20, 30, 50, 100, 150, 200, and 250 ug/cm2 are currently available on the small, "standard" FSU target frames. 50 and 100 ug/cm2 foils are available on slides and can be mounted on any frame upon request. If your experiment will tolerate it, these can be folded over the frame to produce double thickness, achieving 200 ug/cm2 as well. Other thickness will be made in future.

Carbon stripper foils for the Tandem are also manufactured by carbon arc evaporation. These are foils of nominal 200 Angstroms thick and are coated with collodion to facilitate handling during installation. A carbon stripper foil frame has two apertures. The Tandem holds nominally 300 frames, thus providing 600 foil positions. Students are sometimes called upon to mount foils on the frames and/or install the frames in the Tandem.

== Limited Low Melting Point Material Targets ==
Source materials with melting points below about 800 degrees C can be evaporated currently using resistive heating. Other materials with higher melting points can also be used if their vapor pressures at these temperatures are high enough. Targets made with these materials on carbon backings are relatively straightforward at the moment. Self-supporting targets made with these materials ''may'' be possible as well. Requests for these types of targets should be made early and discussed with the targetmaker before assuming they are available.

== CD2 Targets ==
Deuterated Polyethylene targets have been made here, but the techniques used have not yet produced high quality targets. While the capability exists here, more development work is required before these can be considered routine.

== Rolled Metal Targets ==
Very limited capabilities exist for rolled targets. Contact the targetmaker for details.

== Oxygen on Ta Backing ==
Manufactured through electrolysis using high-purity water. Isotopically enriched water can be used.

= Possible Future Capabilities =
* PID controlled substrate heating
* Electron beam evaporation
* In situ reduction-distillation evaporation
* Improved Target Storage Facility
* Improved Rolling capabilities
* Improved CD2 Production

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Target Lab

2025-02-12T16:32:03Z

Pbarber:

= NOTICE =

The Target Lab here at FoxLab has suffered significant atrophy since it was disassembled for asbestos removal. It has very limited capabilities at the moment. Planning is underway to restore it to its previous functionality. Information regarding current and future capabilities will be posted here as time permits.

= General Information =

== Target Frames ==
Standard target frames used here at FoxLab. CAD files for most of these frames are available. Use the contact link below to request them.
<gallery>
File:standard_fsu_tgt_frame.pdf|Original "standard" FSU Target Frame
File:Large fsu tgt frame.pdf|Large FSU Target Frame
File:Sps_fsu_tgt_frame_375.pdf|SPS (old Yale) target frame w/ 0.375" aperture
File:Sps_fsu_tgt_frame_500.PDF|SPS (old Yale) target frame w/ 0.500" aperture
File:Sps_x_fsu_tgt_frame.pdf|Adapter for mounting small FSU frame on SPS(old Yale) target ladder
File:Stripper_foil_frame.pdf|Tandem Terminal Stripper Foil Frame
File:External_2nd_stripper_frame.pdf|External 2nd Stripper Foil Frame
File:Clarion_tgt_frame.pdf|CLARION chamber target frame
</gallery>

= Current Capabilities =
== Pure Lithium Targets ==

One of the unique capabilities available here at FoxLab is the ability to produce pure pseudo-free-standing lithium targets. Lithium metal is evaporated onto a polyvinyl formal resin backing which burns away when placed in beam. These targets are transported under static vacuum from the evaporator to the experimental chamber.

Personnel requesting pure lithium targets should be aware of the following:
* Historically, these have only been manufactured on frames with a nominal 0.375" ( ~ 10 mm ) aperture. Requests for larger apertures will require technique development and success is not assured.
* The chamber in which the experiment will be performed must be capable of accepting one of the two vacuum target barrels available, or a new barrel must be designed/manufactured. As of this writing (15 Sep 2023) the original Yale SPS Chamber, the TR1 Scattering Chamber, the CATRiNA chamber and the newly installed SPS "Wild CeBrAs" chamber qualify.
* It is not uncommon for the polyvinyl formal backings to break during evaporation. It is best to have multiple backings on the target ladder to increase the odds of getting a usable target.
* The polyvinyl formal backing can contribute carbon, hydrogen, and oxygen until it burns away.
* Isotopically enriched lithium is available.
* Typical lithium thickness ranges 50 to 250 ug/cm2.
* The lithium targets must be at the bottom of the target ladder.
* Multiple thicknesses are possible, but the thicker targets must be at the bottom of the target ladder.
* Production of pure lithium targets requires significant evaporator setup. For this reason, lithium targets are typically available for installation in the target chamber Tuesday - Friday, barring extraordinary circumstances.
* Post lithium target production requires significant evaporator clean up. Consequently, if the provided targets are destroyed due to vacuum accident or other misfortune, it can take a full day to recover and make another attempt.
* As long as high vacuum is maintained in the experimental chamber, experiments of over a week in duration are possible on a set of targets.

== Carbon ==
Carbon foils are made by carbon arc evaporation. Foils of 10, 20, 30, 50, 100, 150, 200, and 250 ug/cm2 are currently available on the small, "standard" FSU target frames. 50 and 100 ug/cm2 foils are available on slides and can be mounted on any frame upon request. If your experiment will tolerate it, these can be folded over the frame to produce double thickness, achieving 200 ug/cm2 as well. Other thickness will be made in future.

Carbon stripper foils for the Tandem are also manufactured by carbon arc evaporation. These are foils of nominal 190 Angstroms thick and are coated with collodion to facilitate handling during installation. A carbon stripper foil frame has two apertures. The Tandem holds nominally 300 frames, thus providing 600 foil positions. Students are sometimes called upon to mount foils on the frames and/or install the frames in the Tandem.

== Limited Low Melting Point Material Targets ==
Source materials with melting points below about 800 degrees C can be evaporated currently using resistive heating. Other materials with higher melting points can also be used if their vapor pressures at these temperatures are high enough. Targets made with these materials on carbon backings are relatively straightforward at the moment. Self-supporting targets made with these materials ''may'' be possible as well. Requests for these types of targets should be made early and discussed with the targetmaker before assuming they are available.

== CD2 Targets ==
Deuterated Polyethylene targets have been made here, but the techniques used have not yet produced high quality targets. While the capability exists here, more development work is required before these can be considered routine.

== Rolled Metal Targets ==
Very limited capabilities exist for rolled targets. Contact the targetmaker for details.

== Oxygen on Ta Backing ==
Manufactured through electrolysis using high-purity water. Isotopically enriched water can be used.

= Possible Future Capabilities =
* PID controlled substrate heating
* Electron beam evaporation
* In situ reduction-distillation evaporation
* Improved Target Storage Facility
* Improved Rolling capabilities
* Improved CD2 Production

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Standard Laboratory Vacuum System Stations

2024-10-16T15:41:11Z

Pbarber: /* Standard Laboratory Vacuum System Stations */

== Standard Laboratory Vacuum System Stations ==
=== Introduction ===
In order to achieve high vacuum (nominally ~ 1 x 10E-6 Torr) it is necessary to combine various vacuum technology components into a system, sometimes colloquially referred to as a "stack." Throughout our lab, there are vacuum stations that are used to achieve high vacuum in different sections of the accelerator. Typically, anywhere the beamlines or accelerator can be separated by isolation valves, a station exists between those valves. It is undesirable to have a "dead section" of beamline - a section that is isolated by valves but without a vacuum station. This page explains the basic stacks or systems in used at each station throughout our lab.
=== Turbo-Pump Based Stations ===
The Turbo-Pump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Turbo pump, or more exactingly turbomolecular pump, systems are ''throughput'' pumping systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Turbo pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the turbo's discharge port and atmosphere. In our lab, this roughing pump is typically an oil-sealed, rotary-vane vacuum pump but may sometimes be an oil-free, dry scroll pump.

The standard turbo pump station consists of the following components:
* A single turbomolecular vacuum pump.
* A single roughing pump.
* An electro-pneumatically operated, high-throughput, gate valve.
* A hand operated (usually) or an electro-pneumatically operated (rarely) foreline valve.
* A molecular-sieve foreline trap.
* A foreline vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the turbo and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the turbo inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the turbo pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the turbo is in NORMAL OPERATION (running at full speed)''' and that the foreline pressure is good ( < 50 mTorr ). Some of our turbos have a LOW SPEED setting that can be employed when not in use to prolong bearing life. The turbo should be brought to full speed before placing online.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below a few hundred millitor and quickly recover. Danger to the turbo can occur if the foreline remains well above 50 mTorr for a prolonged period (10's of minutes). Prolonged exposures to high foreline pressures will cause bearing overheating and pump shut-down. Never walk off and leave a turbo running w/ high foreline pressures. If the foreline pressure fails to start dropping within a few minutes, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a turbo pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Be mindful of turbo pump temperature and foreline pressure until both are back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the turbo's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the turbo is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.
*'''MagLev Crash''': A rapid gas inrush in a magnetically levitated turbo can overwhelm the magnetic field bearings and cause the turbo to "sit down" on it's emergency bearings. When this occurs the turbo will "scream" loudly and can easily startle nearby personnel. MagLev crashes should be avoided if at all possible. Most maglev turbos have a limited number of times that this may occur before the emergency bearings must be replaced at significant cost.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

All of the turbo pumps in operation in our lab use one of two bearing types: (1) static or dynamic magnetic bearings, or (2) permanently lubricated ceramic ball bearings. In both of these cases, the pumps are run until failure. Some of our turbos have a hybrid bearing technology where one bearing is magnetic, but the other is ceramic ball. The Re-Buncher turbo does have a battery that must be replaced periodically. Cooling fan operation must be maintained when in operation unless approved by staff. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

=== Cryopump Based Stations ===
The Cryopump Based Vacuum Station is a system used to produce high vacuum ( 10-6 < X < 10-9 Torr ) in beamlines and experimental chambers through out the lab. Cryopumps are ''capture'' pumps, which means that the gases that are removed from the evacuated space are stored within the pump until the pump's capacity is reached. These gases must then be expelled through a process known as regeneration. Modern cryopumps can do this automatically. Sadly, our cryopumps are not modern cryopumps and regeneration must be done manually.

The standard cryopump station consists of the following components:
* A single cryopump.
* A single cryopump compressor.
* An electro-pneumatically operated, high-throughput, gate valve.
* A pump-mounted vacuum gauge.
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit.
* A panel-mounted indicator & control panel.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
A cryopump is a capture pump and will run continuously until one of the following occurs:
#Operation is interrupted long enough to allow the pump to warm and break its vacuum insulation
#Pump capacity is reached.
#Pump Failure occurs.

In a cryopump based vacuum station, the cryopump runs 24/7 and captures gas from the chamber by cryo-condensation and cryo-adsorption. If lab operations dictate that the beamline or chamber be vented, then the cryopump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 30 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the cryopump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 30 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the cryopump is cold''' (< ~ 25K) and that the pump pressure is low (< ~ 10 mTorr).
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the chamber/beamline pressure''' and ensure that it begins to fall. This should occur rapidly, as our standard cryopump provides a very high pumping speed for water vapor and nitrogen - the predominant gases in atmosphere. Check periodically to ensure that the system achieves a nominal pressure and the pump temperature remains nominal.

'''CAUTIONS'''
*Opening the cryopump when the chamber pressure is too high can cause the cryopump to "crash" or warm up beyond recovery.
*When warming, cryopumps can overpressure. All cryopumps have a pressure relief device of some kind, typically a spring-loaded, elastomer-sealed valve. Cryopumps designed for ultra-high vacuum systems may also have a single-use burst disk which ruptures violently when actuated. (none of our cryopumps have burst disks)
*When warming, the external cryopanel housing can become so cold that it condenses water vapor and can create a drip hazard for equipment located below it.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.

Maintenance actions involving cryopumps almost always involve thermal cycling and therefore can involve prolonged periods of time. It is not uncommon to lose the better part of a day of data collection due to a cryopump issue.

Common cryopump maintenance actions include:
#'''Regeneration'''. This is the process of ridding the pump of the captured gas. Regeneration is needed when the pump reaches capacity or develops a cold short--an ice bridge between the interior cryopanels and exterior housing which prevents the pump from achieving it's operating temperature. Regeneration requires thermal cycling. Typically regeneration is performed by staff during normal business hours. All other maintenance actions will require regeneration as part of the maintenance action. The following procedure for regeneration is provided in case those unfamiliar with the process are required to perform it to restore operations.
##'''Isolate the cryopump''' from the vacuum chamber or beamline by shutting the gate valve. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve.
##'''Turn off the cryopump compressor'''.
##'''Vent the cryopump'''. Locate a source of dry nitrogen, if possible, and use this to vent the cryopump. Allow the cryopump to come to atmospheric pressure. Use caution when connecting the dry nitrogen source and ensure that the pump is never over-pressured.
##'''Open the relief valve'''. Carefully pull the relief valve open and place something relatively soft in the elastomer seal to prevent closure. A wooden cotton swab handle or a nylon tie-wrap works well.
##'''Start Dry Nitrogen Bleed'''. Establish a slow-flow from the dry nitrogen line and connect it to the pump-out valve so that a small amount of dry nitrogen flows through the pump and out of the relief valve.
##'''Start the Heater'''. If one exist, initiate heating on the housing. This is typically done w/ a silicone heat-tape wrapped around the pump housing. '''CAUTION''': Be sure to follow any instructions on the heater control. Over heating the pump can melt the indium components!
##'''Monitor the pump temperature'''. Allow the pump to come to room temperature, or slightly above. Some of our pumps have silicon diode thermometry and will read the temperature fairly well throughout the range to ambient. Other pumps have hydrogen vapor pressure thermometry and do not accurately read the temperature above the low Kelvin range. Allow these pumps to warm/flow for '''at least''' two hours, and up to four if possible.
##'''Stop Dry Nitrogen Flow'''. Once the pump has reached ambient temperature or slightly above, stop the flow of nitrogen. Remove the nitrogen source connection. Remove the device that was used to hold the relief valve open and visually confirm that it closes properly.
##'''Turn Off Heating'''. If a heater was used to warm the pump during flow, turn it off now.
##'''Pump out the Cryopanels'''. Connect an oil-free pumping cart to the cryopump and initate pumping. It can take a while to pump out a cryopump, but if the pump was fully warmed and flowed, it should be done in less than two hours.
##'''Test the Pump Out'''. Verify that the pump is fully evacuated by ensuring the following criteria: (1) pump pressure is 30 mTorr or less, and (2) the pressure in the pump has a rate of rise < 15 mTorr/min when the roughing cart is isolated from the pump. If these criteria are met, re-open the valve to the scroll cart and proceed to the next step.
##'''Restart the Cryopump'''. Using the switch on the compressor, restart the cryopump and allow it to run.
##'''Stop the Pump Out'''. Within about 10 mins of starting the compressor, shut the valve to isolate the scroll cart.
##'''Monitor the Pump'''. On pumps with silicon diode thermometry, one need only monitor the temperature display and verify that the pump is cooling down. On pumps with hydrogen vapor bulb thermometry, there will be no visible sign of temperature change until the pump is in the tens of Kelvin range. On these pumps, the pump pressure should be monitored for indications that the pump pressure is dropping and that this pressure drop occurs within a few tens of minutes. Once temperature and/or pressure drop are confirmed, one need simply wait for the pump to achieve nominal operating temperature. This should usually occur in 2-3 hours.
##'''Place Pump in Service'''. Once the pump has achieved nominal operating temperature, verify that the chamber pressure is below 30 mTorr (the lower the better) and then open the gate valve. Verify that the chamber pressure drops rapidly. Monitor the pump pressure for the next few tens of minutes to ensure the cryopump doesn't crash (become overwhelmed and warm up).
##'''Paperwork'''. If there exists a tag on the cryopump, mark the date and the fact that regeneration was performed for future reference.
#'''Cold Head Purge'''. This involves removing contaminant gases from the cold head. During normal operation, gases other than helium will tend to freeze withing the cold head's (pump's) helium circuit and impair operations. If allowed to build too much, this ice can mechanically damage components in the cold head. Similar to regeneration, the pump is stopped and the cold head is disconnected quickly from the compressor. Once warm, the thawed contaminant gases are purged from the cold head's helium circuit. Cold head purge require implicit regeneration of the cryopanels.
#'''Compressor Purge'''. When contaminant gases are significant, it can be necessary to purge the compressor as well. Compressor Purges require implicit Cold Head Purge and Cryopanel Regeneration.
#'''Adsorber Change'''. This is a scheduled, preventive maintenance action, typically performed annually. The adorber is basically an oil filter that prevents compressor oil from entering the cold head. Failure to perform this maintenance on schedule will result in contamination and failure of the cold head and necessitate a costly rebuild. Adsorber changes require implicit Cryopanel Regeneration, and usually include Cold Head Purges as well.

=== Diffusion Pump Based Stations (rare) ===

The Diffusion Pump Based Vacuum Station is a system used to produce high vacuum (10-6 < X < 10-9 Torr ) in some specialized systems within the laboratory, notably the SNICS source and one of the target lab evaporators. Diffusion pumps, in general, are being replaced by more modern alternatives and are typically no longer included in new designs. Feel free to skip this section if you're short on time. Diffusion pump systems are ''throughput'' systems, which means that the gases that are removed from the evacuated space are continuously discharged into the atmosphere. Diffusion pumps cannot discharge to atmospheric pressure and require a roughing pump to interface between the diffusion pump's discharge port and atmosphere. In our lab, this roughing pump is an oil-sealed, rotary-vane vacuum pump.

The standard diffusion pump station consists of the following components:
* A single diffusion pump.
* A single roughing pump.
* An electro-pneumatically or manually operated, high-throughput, gate valve.
* An electro-pneumatically or manually operated foreline valve.
* A foreline vacuum pump gauge
* Dual chamber/beamline vacuum gauges.
* A vacuum pump gate valve interlock circuit. (on some systems)
* A panel-mounted indicator & control panel. (on some systems)
* A source of water cooling.
* Various interconnecting vacuum hoses and fittings.

==== Operation ====
Normally, the diffusion pump and rotary pump (RP) run 24/7 and maintain chamber high vacuum. If lab operations dictate that the beamline or chamber be vented, then the diffusion pump inlet gate valve is manually shut to protect the pumping system. The gate valve interlock should be left in the PROTECTED mode while the work is performed as it will prevent the inadvertent opening of the inlet gate valve. Once the work is completed, the beamline or chamber should be evacuated w/ a portable system, preferably a dry-scroll pump-out cart until the chamber pressure is less than 50 mTorr. The larger the volume, the lower the pressure one should try to obtain before opening to the pump inlet gate valve.

When opening the chamber to the diffusion pump station, the following steps should be performed:

#'''Verify that the chamber pressure is < 50 mTorr''' or more preferably, as close to the ultimate pressure of the portable pumping cart being used.
#'''Verify that the diffusion pump is at its operating temperature and has water cooling''' and that the foreline pressure is good ( < 50 mTorr ). If a refrigerated baffle or cryotrap is installed, verify that it is functional and/or filled and thus cold.
#'''Isolate the portable pump-out cart''' by shutting the valve on the chamber or beamline.
#'''Place the Gate Valve Interlock system in BYPASS mode.''' This allows operation of the gate valve w/o protection. We do this to prevent gate valve oscillation, a full explanation of which occurs later.
#'''Place the Gate Valve switch in the open position.'''
#'''Monitor the foreline pressure.''' It should rise rapidly, slow, and then begin to drop in a relatively brief time. Ideally, the foreline pressure should stay below 300 millitor and quickly recover. If the foreline pressure fails to start dropping within a minute, shut the gate valve, place the interlock in the PROTECTED mode, and contact staff for assistance.
#'''Restore the Interlock.''' Once the foreline pressure has dropped to 50 mTorr or less, you ''should'' be able to place the interlock back in the PROTECTED mode. The foreline pressure gauge will indicate whether the interlock threshold setting is satisfied or not. If the gate valve shuts at this point, this threshold is not satisfied. Simply place the interlock back in BYPASS mode and the valve switch in the OPEN thus re-opening the gate valve and wait for the foreline pressure to drop further.
'''CAUTIONS'''
*'''NEVER''' leave a diffusion pump based vacuum system in the UNPROTECTED mode unsupervised without staff approval.
*Monitor foreline pressure until back to nominal values.
*'''Gate Valve Oscillation''' occurs with throughput systems when the gate valve is left in PROTECTED mode while pumping down the chamber. It is caused when the diffusion pump's discharge pressure exceeds the foreline interlock threshold pressure as it begins to take in gas from the chamber. When this happens, the interlock will trip and shut the gate valve. With the gate valve shut, the diffusion pump is no longer taking in gas from the chamber and thus its discharge pressure drops below the interlock's threshold pressure. Now the interlock is once again satisfied and opens the gate valve, starting the whole process once again. Typically, this will continue until the the system restores pumping and will be fine, but it causes excess wear on our gate valves and should be avoided when possible.

==== Maintenance ====
Students are not expected to perform maintenance on these systems, however an understanding will help students know when to alert staff to maintenance issues.
Diffusion pumps are surprisingly maintenance free. Occasional oil changes are needed when the oil becomes contaminated, or fractionates beyond tolerance. Sufficient cooling water flow and temperatures must be maintained at all times when the pump is running. The cal-rod or plate heater can fail, as can the high-temperature wiring components. The Klixon thermal safety switch can fail. Loss of cooling water in combination with a Klixon safety switch failure can result in severe to catastrophic damage. Trust me. The oil-lubricated, rotary-vane roughing pumps require oil changes, shaft seal changes, and occasional rebuilds. Dry-scroll roughing pumps require tip-seal replacements periodically.

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Target Lab

2024-08-09T14:54:16Z

Pbarber: /* Pure Lithium Targets */

= NOTICE =

The Target Lab here at FoxLab has suffered significant atrophy since it was disassembled for asbestos removal. It has very limited capabilities at the moment. Planning is underway to restore it to its previous functionality. Information regarding current and future capabilities will be posted here as time permits.

= General Information =

== Target Frames ==
Standard target frames used here at FoxLab. CAD files for most of these frames are available. Use the contact link below to request them.
<gallery>
File:standard_fsu_tgt_frame.pdf|Original "standard" FSU Target Frame
File:Large fsu tgt frame.pdf|Large FSU Target Frame
File:Sps_fsu_tgt_frame_375.pdf|SPS (old Yale) target frame w/ 0.375" aperture
File:Sps_fsu_tgt_frame_500.PDF|SPS (old Yale) target frame w/ 0.500" aperture
File:Sps_x_fsu_tgt_frame.pdf|Adapter for mounting small FSU frame on SPS(old Yale) target ladder
File:Stripper_foil_frame.pdf|Tandem Terminal Stripper Foil Frame
File:External_2nd_stripper_frame.pdf|External 2nd Stripper Foil Frame
File:Clarion_tgt_frame.pdf|CLARION chamber target frame
</gallery>

= Current Capabilities =
== Pure Lithium Targets ==

One of the unique capabilities available here at FoxLab is the ability to produce pure pseudo-free-standing lithium targets. Lithium metal is evaporated onto a polyvinyl formal resin backing which burns away when placed in beam. These targets are transported under static vacuum from the evaporator to the experimental chamber.

Personnel requesting pure lithium targets should be aware of the following:
* Historically, these have only been manufactured on frames with a nominal 0.375" ( 10 mm ) aperture. Requests for larger apertures will require technique development and success is not assured.
* The chamber in which the experiment will be performed must be capable of accepting one of the two vacuum target barrels available, or a new barrel must be designed/manufactured. As of this writing (15 Sep 2023) the original Yale SPS Chamber, the TR1 Scattering Chamber, the CATRiNA chamber and the newly installed SPS "Wild CeBrAs" chamber qualify.
* It is not uncommon for the polyvinyl formal backings to break during evaporation. It is best to have multiple backings on the target ladder to increase the odds of getting a usable target.
* The polyvinyl formal backing can contribute carbon, hydrogen, and oxygen until it burns away.
* Isotopically enriched lithium is available.
* Typical lithium thickness ranges 50 to 250 ug/cm2.
* The lithium targets must be at the bottom of the target ladder.
* Multiple thicknesses are possible, but the thicker targets must be at the bottom of the target ladder.
* Production of pure lithium targets requires significant evaporator setup. For this reason, lithium targets are typically available for installation in the target chamber Tuesday - Friday, barring extraordinary circumstances.
* Post lithium target production requires significant evaporator clean up. Consequently, if the provided targets are destroyed due to vacuum accident or other misfortune, it can take a full day to recover and make another attempt.
* As long as high vacuum is maintained in the experimental chamber, experiments of over a week in duration are possible on a set of targets.

== Carbon ==
Carbon foils are made by carbon arc evaporation. Foils of 10, 20, 30, 50, 100, 150, 200, and 250 ug/cm2 are currently available on the small, "standard" FSU target frames. 50 and 100 ug/cm2 foils are available on slides and can be mounted on any frame upon request. If your experiment will tolerate it, these can be folded over the frame to produce double thickness, achieving 200 ug/cm2 as well. Other thickness will be made in future.

Carbon stripper foils for the Tandem are also manufactured by carbon arc evaporation. These are foils of nominal 190 Angstroms thick and are coated with collodion to facilitate handling during installation. A carbon stripper foil frame has two apertures. The Tandem holds nominally 300 frames, thus providing 600 foil positions. Students are sometimes called upon to mount foils on the frames and/or install the frames in the Tandem.

== Limited Low Melting Point Material Targets ==
Source materials with melting points below about 800 degrees C can be evaporated currently using resistive heating. Other materials with higher melting points can also be used if their vapor pressures at these temperatures are high enough. Targets made with these materials on carbon backings are relatively straightforward at the moment. Self-supporting targets made with these materials ''may'' be possible as well. Requests for these types of targets should be made early and discussed with the targetmaker before assuming they are available.

== CD2 Targets ==
Deuterated Polyethylene targets have been made here, but the techniques used have not yet produced high quality targets. While the capability exists here, more development work is required before these can be considered routine.

== Rolled Metal Targets ==
Very limited capabilities exist for rolled targets. Contact the targetmaker for details.

== Oxygen on Ta Backing ==
Manufactured through electrolysis using high-purity water. Isotopically enriched water can be used.

= Possible Future Capabilities =
* PID controlled substrate heating
* Electron beam evaporation
* In situ reduction-distillation evaporation
* Improved Target Storage Facility
* Improved Rolling capabilities
* Improved CD2 Production

= Contact =
Powell Barber mailto:pbarber@fsu.edu

File:2022 crane inspection report.pdf

2024-05-16T19:41:45Z

Pbarber:

File:2024apr crane inspection report.pdf

2024-05-16T19:38:06Z

Pbarber:

Tandem Beamline Isolation (Fast Valve) System

2024-05-08T14:19:50Z

Pbarber:

Target Lab

2023-11-01T14:55:01Z

Pbarber: /* Target Frames */

= NOTICE =

The Target Lab here at FoxLab has suffered significant atrophy since it was disassembled for asbestos removal. It has very limited capabilities at the moment. Planning is underway to restore it to its previous functionality. Information regarding current and future capabilities will be posted here as time permits.

= General Information =

== Target Frames ==
Standard target frames used here at FoxLab. CAD files for most of these frames are available. Use the contact link below to request them.
<gallery>
File:standard_fsu_tgt_frame.pdf|Original "standard" FSU Target Frame
File:Large fsu tgt frame.pdf|Large FSU Target Frame
File:Sps_fsu_tgt_frame_375.pdf|SPS (old Yale) target frame w/ 0.375" aperture
File:Sps_fsu_tgt_frame_500.PDF|SPS (old Yale) target frame w/ 0.500" aperture
File:Sps_x_fsu_tgt_frame.pdf|Adapter for mounting small FSU frame on SPS(old Yale) target ladder
File:Stripper_foil_frame.pdf|Tandem Terminal Stripper Foil Frame
File:External_2nd_stripper_frame.pdf|External 2nd Stripper Foil Frame
File:Clarion_tgt_frame.pdf|CLARION chamber target frame
</gallery>

= Current Capabilities =
== Pure Lithium Targets ==

One of the unique capabilities available here at FoxLab is the ability to produce pure pseudo-free-standing lithium targets. Lithium metal is evaporated onto a polyvinyl formal backing which burns away when placed in beam. These targets are transported under static vacuum from the evaporator to the experimental chamber.

Personnel requesting pure lithium targets should be aware of the following:
* Historically, these have only been manufactured on frames with a nominal 0.375" ( 10 mm ) aperture. Requests for larger apertures will require technique development and success is not assured.
* The chamber in which the experiment will be performed must be capable of accepting one of the two vacuum target barrels available, or a new barrel must be designed/manufactured. As of this writing (15 Sep 2023) the original Yale SPS Chamber, the TR1 Scattering Chamber, the CATRiNA chamber and the newly installed SPS "Wild CeBrAs" chamber qualify.
* It is not uncommon for the polyvinyl formal backings to break during evaporation. It is best to have multiple backings on the target ladder to increase the odds of getting a usable target.
* The polyvinyl formal backing can contribute carbon, hydrogen, and oxygen until it burns away.
* Isotopically enriched lithium is available.
* Typical lithium thickness ranges 50 to 250 ug/cm2.
* The lithium targets must be at the bottom of the target ladder.
* Multiple thicknesses are possible, but the thicker targets must be at the bottom of the target ladder.
* Production of pure lithium targets requires significant evaporator setup. For this reason, lithium targets are typically available for installation in the target chamber Tuesday - Friday, barring extraordinary circumstances.
* Post lithium target production requires significant evaporator clean up. Consequently, if the provided targets are destroyed due to vacuum accident or other misfortune, it can take a full day to recover and make another attempt.
* As long as high vacuum is maintained in the experimental chamber, experiments of over a week in duration are possible on a set of targets.

== Carbon ==
Carbon foils are made by carbon arc evaporation. Foils of 10, 20, 30, 50, 100, 150, 200, and 250 ug/cm2 are currently available on the small, "standard" FSU target frames. 50 and 100 ug/cm2 foils are available on slides and can be mounted on any frame upon request. If your experiment will tolerate it, these can be folded over the frame to produce double thickness, achieving 200 ug/cm2 as well. Other thickness will be made in future.

Carbon stripper foils for the Tandem are also manufactured by carbon arc evaporation. These are foils of nominal 190 Angstroms thick and are coated with collodion to facilitate handling during installation. A carbon stripper foil frame has two apertures. The Tandem holds nominally 300 frames, thus providing 600 foil positions. Students are sometimes called upon to mount foils on the frames and/or install the frames in the Tandem.

== Limited Low Melting Point Material Targets ==
Source materials with melting points below about 800 degrees C can be evaporated currently using resistive heating. Other materials with higher melting points can also be used if their vapor pressures at these temperatures are high enough. Targets made with these materials on carbon backings are relatively straightforward at the moment. Self-supporting targets made with these materials ''may'' be possible as well. Requests for these types of targets should be made early and discussed with the targetmaker before assuming they are available.

== CD2 Targets ==
Deuterated Polyethylene targets have been made here, but the techniques used have not yet produced high quality targets. While the capability exists here, more development work is required before these can be considered routine.

== Rolled Metal Targets ==
Very limited capabilities exist for rolled targets. Contact the targetmaker for details.

== Oxygen on Ta Backing ==
Manufactured through electrolysis using high-purity water. Isotopically enriched water can be used.

= Possible Future Capabilities =
* PID controlled substrate heating
* Electron beam evaporation
* In situ reduction-distillation evaporation
* Improved Target Storage Facility
* Improved Rolling capabilities
* Improved CD2 Production

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Tandem Beamline Isolation (Fast Valve) System

2023-10-10T13:03:47Z

Pbarber: /* Fault Integration with Tandem Pelletron */

Tandem Beamline Isolation (Fast Valve) System

2023-10-10T13:02:38Z

Pbarber: /* Fault Integration with Tandem Pelletron */

Tandem Beamline Isolation (Fast Valve) System

2023-10-10T12:53:02Z

Pbarber:

Target Lab

2023-09-15T13:08:24Z

Pbarber: /* Pure Lithium Targets */

= NOTICE =

The Target Lab here at FoxLab has suffered significant atrophy since it was disassembled for asbestos removal. It has very limited capabilities at the moment. Planning is underway to restore it to its previous functionality. Information regarding current and future capabilities will be posted here as time permits.

= General Information =

== Target Frames ==
Standard target frames used here at FoxLab. CAD files for most of these frames are available. Use the contact link below to request them.
<gallery>
File:standard_fsu_tgt_frame.pdf|Original "standard" FSU Target Frame
File:Large fsu tgt frame.pdf|Large FSU Target Frame
File:Sps_fsu_tgt_frame_375.pdf|SPS(old Yale) target frame w/ 0.375" aperture
File:Sps_fsu_tgt_frame_500.PDF|SPS(old Yale) target frame w/ 0.500" aperture
File:Sps_x_fsu_tgt_frame.pdf|Adapter for mounting small FSU frame on SPS(old Yale) target ladder
File:Stripper_foil_frame.pdf|Tandem Terminal Stripper Foil Frame
File:External_2nd_stripper_frame.pdf|External 2nd Stripper Foil Frame
File:Clarion_tgt_frame.pdf|CLARION chamber target frame
</gallery>

= Current Capabilities =
== Pure Lithium Targets ==

One of the unique capabilities available here at FoxLab is the ability to produce pure pseudo-free-standing lithium targets. Lithium metal is evaporated onto a polyvinyl formal backing which burns away when placed in beam. These targets are transported under static vacuum from the evaporator to the experimental chamber.

Personnel requesting pure lithium targets should be aware of the following:
* Historically, these have only been manufactured on frames with a nominal 0.375" ( 10 mm ) aperture. Requests for larger apertures will require technique development and success is not assured.
* The chamber in which the experiment will be performed must be capable of accepting one of the two vacuum target barrels available, or a new barrel must be designed/manufactured. As of this writing (15 Sep 2023) the original Yale SPS Chamber, the TR1 Scattering Chamber, the CATRiNA chamber and the newly installed SPS "Wild CeBrAs" chamber qualify.
* It is not uncommon for the polyvinyl formal backings to break during evaporation. It is best to have multiple backings on the target ladder to increase the odds of getting a usable target.
* The polyvinyl formal backing can contribute carbon, hydrogen, and oxygen until it burns away.
* Isotopically enriched lithium is available.
* Typical lithium thickness ranges 50 to 250 ug/cm2.
* The lithium targets must be at the bottom of the target ladder.
* Multiple thicknesses are possible, but the thicker targets must be at the bottom of the target ladder.
* Production of pure lithium targets requires significant evaporator setup. For this reason, lithium targets are typically available for installation in the target chamber Tuesday - Friday, barring extraordinary circumstances.
* Post lithium target production requires significant evaporator clean up. Consequently, if the provided targets are destroyed due to vacuum accident or other misfortune, it can take a full day to recover and make another attempt.
* As long as high vacuum is maintained in the experimental chamber, experiments of over a week in duration are possible on a set of targets.

== Carbon ==
Carbon foils are made by carbon arc evaporation. Foils of 10, 20, 30, 50, 100, 150, 200, and 250 ug/cm2 are currently available on the small, "standard" FSU target frames. 50 and 100 ug/cm2 foils are available on slides and can be mounted on any frame upon request. If your experiment will tolerate it, these can be folded over the frame to produce double thickness, achieving 200 ug/cm2 as well. Other thickness will be made in future.

Carbon stripper foils for the Tandem are also manufactured by carbon arc evaporation. These are foils of nominal 190 Angstroms thick and are coated with collodion to facilitate handling during installation. A carbon stripper foil frame has two apertures. The Tandem holds nominally 300 frames, thus providing 600 foil positions. Students are sometimes called upon to mount foils on the frames and/or install the frames in the Tandem.

== Limited Low Melting Point Material Targets ==
Source materials with melting points below about 800 degrees C can be evaporated currently using resistive heating. Other materials with higher melting points can also be used if their vapor pressures at these temperatures are high enough. Targets made with these materials on carbon backings are relatively straightforward at the moment. Self-supporting targets made with these materials ''may'' be possible as well. Requests for these types of targets should be made early and discussed with the targetmaker before assuming they are available.

== CD2 Targets ==
Deuterated Polyethylene targets have been made here, but the techniques used have not yet produced high quality targets. While the capability exists here, more development work is required before these can be considered routine.

== Rolled Metal Targets ==
Very limited capabilities exist for rolled targets. Contact the targetmaker for details.

== Oxygen on Ta Backing ==
Manufactured through electrolysis using high-purity water. Isotopically enriched water can be used.

= Possible Future Capabilities =
* PID controlled substrate heating
* Electron beam evaporation
* In situ reduction-distillation evaporation
* Improved Target Storage Facility
* Improved Rolling capabilities
* Improved CD2 Production

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Target Lab

2023-08-25T18:40:14Z

Pbarber: /* Carbon */

= NOTICE =

The Target Lab here at FoxLab has suffered significant atrophy since it was disassembled for asbestos removal. It has very limited capabilities at the moment. Planning is underway to restore it to its previous functionality. Information regarding current and future capabilities will be posted here as time permits.

= General Information =

== Target Frames ==
Standard target frames used here at FoxLab. CAD files for most of these frames are available. Use the contact link below to request them.
<gallery>
File:standard_fsu_tgt_frame.pdf|Original "standard" FSU Target Frame
File:Large fsu tgt frame.pdf|Large FSU Target Frame
File:Sps_fsu_tgt_frame_375.pdf|SPS(old Yale) target frame w/ 0.375" aperture
File:Sps_fsu_tgt_frame_500.PDF|SPS(old Yale) target frame w/ 0.500" aperture
File:Sps_x_fsu_tgt_frame.pdf|Adapter for mounting small FSU frame on SPS(old Yale) target ladder
File:Stripper_foil_frame.pdf|Tandem Terminal Stripper Foil Frame
File:External_2nd_stripper_frame.pdf|External 2nd Stripper Foil Frame
File:Clarion_tgt_frame.pdf|CLARION chamber target frame
</gallery>

= Current Capabilities =
== Pure Lithium Targets ==

One of the unique capabilities available here at FoxLab is the ability to produce pure pseudo-free-standing lithium targets. Lithium metal is evaporated onto a polyvinyl formal backing which burns away when placed in beam. These targets are transported under static vacuum from the evaporator to the experimental chamber.

Personnel requesting pure lithium targets should be aware of the following:
* Historically, these have only been manufactured on frames with a nominal 0.375" ( 10 mm ) aperture. Requests for larger apertures will require technique development and success is not assured.
* The chamber in which the experiment will be performed must be capable of accepting one of the two vacuum target barrels available, or a new barrel must be designed/manufactured. As of this writing (15 Sep 2022) the original Yale SPS Chamber, the TR1 Scattering Chamber, and the CATRiNA chambers qualify. The newly installed SPS "Wild CeBrAs" chamber may also qualify.
* It is not uncommon for the polyvinyl formal backings to break during evaporation. It is best to have multiple backings on the target ladder to increase the odds of getting a usable target.
* The polyvinyl formal backing can contribute carbon, hydrogen, and oxygen until it burns away.
* Isotopically enriched lithium is available.
* Typical lithium thickness ranges 50 to 250 ug/cm2.
* The lithium targets must be at the bottom of the target ladder.
* Multiple thicknesses are possible, but the thicker targets must be at the bottom of the target ladder.
* Production of pure lithium targets requires significant evaporator setup. For this reason, lithium targets are typically available for installation in the target chamber Tuesday - Friday, barring extraordinary circumstances.
* Post lithium target production requires significant evaporator clean up. Consequently, if the provided targets are destroyed due to vacuum accident or other misfortune, it can take a full day to recover and make another attempt.
* As long as high vacuum is maintained in the experimental chamber, experiments of over a week in duration are possible on a set of targets.

== Carbon ==
Carbon foils are made by carbon arc evaporation. Foils of 10, 20, 30, 50, 100, 150, 200, and 250 ug/cm2 are currently available on the small, "standard" FSU target frames. 50 and 100 ug/cm2 foils are available on slides and can be mounted on any frame upon request. If your experiment will tolerate it, these can be folded over the frame to produce double thickness, achieving 200 ug/cm2 as well. Other thickness will be made in future.

Carbon stripper foils for the Tandem are also manufactured by carbon arc evaporation. These are foils of nominal 190 Angstroms thick and are coated with collodion to facilitate handling during installation. A carbon stripper foil frame has two apertures. The Tandem holds nominally 300 frames, thus providing 600 foil positions. Students are sometimes called upon to mount foils on the frames and/or install the frames in the Tandem.

== Limited Low Melting Point Material Targets ==
Source materials with melting points below about 800 degrees C can be evaporated currently using resistive heating. Other materials with higher melting points can also be used if their vapor pressures at these temperatures are high enough. Targets made with these materials on carbon backings are relatively straightforward at the moment. Self-supporting targets made with these materials ''may'' be possible as well. Requests for these types of targets should be made early and discussed with the targetmaker before assuming they are available.

== CD2 Targets ==
Deuterated Polyethylene targets have been made here, but the techniques used have not yet produced high quality targets. While the capability exists here, more development work is required before these can be considered routine.

== Rolled Metal Targets ==
Very limited capabilities exist for rolled targets. Contact the targetmaker for details.

== Oxygen on Ta Backing ==
Manufactured through electrolysis using high-purity water. Isotopically enriched water can be used.

= Possible Future Capabilities =
* PID controlled substrate heating
* Electron beam evaporation
* In situ reduction-distillation evaporation
* Improved Target Storage Facility
* Improved Rolling capabilities
* Improved CD2 Production

= Contact =
Powell Barber mailto:pbarber@fsu.edu

Tandem Beamline Isolation (Fast Valve) System

2023-06-02T15:54:39Z

Pbarber: /* Technical Description and Troubleshooting */

Tandem Beamline Isolation (Fast Valve) System

2023-06-02T15:54:03Z

Pbarber: /* Technical Description and Troubleshooting */

Tandem Beamline Isolation (Fast Valve) System

2023-06-01T15:24:42Z

Pbarber: /* Operation */

Tandem Beamline Isolation (Fast Valve) System

2023-06-01T15:22:19Z

Pbarber: /* Operation */

Tandem Beamline Isolation (Fast Valve) System

2023-06-01T14:49:01Z

Pbarber:

Tandem Beamline Isolation (Fast Valve) System

2023-05-31T20:52:35Z

Pbarber: /* Sensor Indication and Control */

Tandem Beamline Isolation (Fast Valve) System

2023-05-31T20:48:46Z

Pbarber: /* Sensor Indication and Control */

Tandem Beamline Isolation (Fast Valve) System

2023-05-31T20:40:42Z

Pbarber:

Tandem Beamline Isolation (Fast Valve) System

2023-05-31T19:20:43Z

Pbarber:

Tandem Beamline Isolation (Fast Valve) System

2023-05-31T18:54:42Z

Pbarber: