CATRiNA
Introduction
The Compound Array for Transfer Reactions in Nuclear Astrophysics (CATRiNA) [1] is a neutron detector array located at Florida State University. CATRiNA is composed of 32 deuterated-benzene (Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \textrm{C}_6 \textrm{D}_6 } ) liquid scintillators. The array consists of 16 "small" detectors each contained in a 2" x 2" (diameter x thickness) aluminum cell and 16 "large" detectors that are each contained in 4" x 2" aluminum cells. Due to the anisotropic light-output spectrum of of neutron-deuterium scattering, the light-output can be converted to the neutron energy without time-of-flight information in a process known as spectrum unfolding [2]. Please refer [| here] for setting up the HV source for CATRiNA.
Light-Output Response
From page 570-571 of Radiation Detection and Measurement by Knoll, the recoil neutron energy is given as a function of the target recoil angle in the lab frame Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \theta } , incident neutron energy Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_n } , and nucleon number of target nucleus Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle A }
Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{recoil} = \frac{4A}{(1+A)^2}cos^2\theta E_n }
For maximum energy transfer, Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \theta = 0 } , and
Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{recoil} = \frac{4A}{(1+A)^2} E_n }
For deuterium, Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle A = 2 } which implies a maximum deposited neutron energy of Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E_{recoil}/E_n = \frac{8}{9} } .
From previous work, the light-output response of a given CATRiNA detector can be parameterized as a function of incident neutron energy and experimentally-extracted parameters:
Failed to parse (SVG with PNG fallback (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle LO = aE_{dep}-b(1-e^{-cE_{dep}}) }
The light output parameters are given by the following table [2]
| Size | a | b | c |
|---|---|---|---|
| 2" x 2" | 0.6193 | 2.036 | 0.2592 |
| 4" x 2" | 0.6109 | 1.946 | 0.2625 |
PMT Bias
The CATRiNA Photo-Multiplier Tubes (PMTs) require bias to function. Below is a table of optimized biases for the R7724 (2" x 2") PMTs:
| PMT Channel | Bias (V) |
|---|---|
| 0 | -1225 |
| 1 | -1225 |
| 2 | -1225 |
| 3 | -1225 |
| 4 | -1225 |
| 5 | -1275 |
| 6 | -1400 |
| 7 | -1400 |
| 8 | -1200 |
| 9 | -1400 |
| 10 | -1250 |
| 11 | -1225 |
| 12 | -1325 |
| 13 | -1300 |
| 14 | -1375 |
| 15 | -1300 |
The 9821B (4" x 2") PMTs:
| PMT Channel | Bias (V) |
|---|---|
| 0 | -1725 |
| 1 | -1700 |
| 2 | -1675 |
| 3 | -1800 |
| 4 | -1700 |
| 5 | -1750 |
| 6 | -1650 |
| 7 | -1725 |
| 8 | -1750 |
| 9 | -1725 |
| 10 | -1725 |
| 11 | -1800 |
| 12 | -1700 |
| 13 | -1725 |
| 14 | -1885 |
| 15 | -1735 |
Digitizer setup for coincident with RF
Digitizer 1 is the master, and received the RF-coin signal. Digitizer 2 and 3 are the slaves, connected to the neutron detectors
The TRG-OUT of digi-2 and -3 will be "on" when ever any channel is fired. To do so, the Local Shaped Trigs [G] must be OR.
also, the TRG-OUT Mode is Trigger (Mask) and the TRG-OUT Mask buttons are green for all channels.
Time sync
Digitizer 1 is SW controll and internal clock. The TRG-OUT mode is "RUN".
Digitizer 2 and 3 are S-IN and external clock.
Contact
Sergio Almaraz-Calderon mailto:salmarazcalderon@fsu.edu
References
- ↑ J. F. Perello et al. NIMA 930, 196 (2019) https://doi.org/10.1016/j.nima.2019.03.084
- ↑ 2.0 2.1 A. B. Morelock et al. NIMA 1034, 166759 (2022) https://doi.org/10.1016/j.nima.2022.166759