[Halld-pid] [EXTERNAL] TOF PMT replacements

[Paul Eugenio]

Beni,

We replaced the following 4 TOF PMTs:

TOF-UP-24
TOF-DW-24
TOF-N-20
TOF-S-21

Recall that we installed PMTs from the new batch from Hamamatsu.  The new modules are H13795 whereas the original H10534 have been discontinued.  These should be identical to the original but with slightly lower gain (1E+06min at 1750V).     I plan to take the 4 old PMTs to FSU to bench test.

We turned on HV using the current channel set values for each new PMT along with 2 channels below and 2 channels above each new one for comparisons (20 channels total).  The current draw looked consistent and the disc. scaler rates were all 10-30 Hz except for TOF-UP-24 which was 40-70 Hz.  We test for light leaks and none were observed.  

Paul


--
Paul Eugenio, Professor & Department Chair
Florida State University
Department of Physics
Tallahassee, Florida,  USA 32306

(850) 644-2338
peugenio at fsu.edu