LINAC

NEED PROOF READING

Power Outage Procedure

When the building power is interrupted the Helium liquefier will stop along with its associated compressors. After this happens the linac boil off will begin to vent through a 1” pressure relief valve located behind the liquefiers. Do not be alarmed by this as it is designed to operate in this manner.

The linac chart recorder auto dialer will activate and someone on the linac list will be “beeped”. He will usually call the lab on the 644-6763 line before coming in. If no one calls within 15 minutes, call someone of the call list (see notice by phone in the control room).

Of the following procedure, item 1 should be done immediately after the emergency power comes on. Items 2 and 3 within 30 minutes or so, items 5 and 6 only if necessary.

1. Open vacuum valves between the cryostats by switching the valve controllers FV5 thru FV8 to the manual open position. This allows the entire linac to be pumped by the turbomolecular and rotary pumps which are on emergency power.
2. Make sure the turbo pumps on the buncher, cryostats B, C and D and the rebuncher have restarted. If not follow procedure posted by each pumping stations electronics rack.
3. Close the J. T. valve on the liquefier (this is the micrometer handled valve) a fraction of a turn clockwise until you feel resistance.
4. Now wait and monitor:
   1. Pressures: 1K dewar, linac and compressor return.
   2. Vacuums in all cryostats.
   3. LN2 and LHe levels in the 1K dewar and cryostats.
   4. Resonator and solenoid temperatures.
5. As each cryostat runs out of LHe and its resonators (and solenoids) start to warm up:
6. Pump the helium out of the slow tuners.
7. Run down the persistent currents in the solenoids.

Helium Refrigerator Restart Procedure

1. Turn on the load 2 RS compressors (look in the log book for information on which 2 were being used) using compressor start buttons on the liquefier.
2. Defrost o-rings on relief valves as required.
3. Start the appropriate liquefier:
4. Push the liquefier start button.
5. Turn the flywheel c.c.w. until the machine starts to run.
6. Open the J. T. valve to 0.085.
7. Return FV5 thru FV8 to auto position.
8. Restart the turbopumps just upstream from the 90◦ magnet and on the switching magnet (note: before starting the tumbopumps, make sure the foreline pumps are running and the ball valves to the turbos have been re-opened with foreline vacuum < 50 m.)