Pion Meeting January 13 2023 3:30PM ET
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Zoom link: https://jlab-org.zoomgov.com/j/1608212513?pwd=M25LR1hzN3hLWm0xaFFETjZ0U1lQZz09
Agenda
- (Simona) PMT gain measurements on bench at JLab
Attendance
Neven, David, Elham, Simona, Dustin
Minutes
- (Simona): Have got dark-box studies of the PMT (H1397) sent from Manitoba working. Needed amplification (x5 up to x9) with CAEN M978 module. Data taken with Flash ADC FADC250, in sample mode. Set threshold 20 channels above pedestal (4.9mV). Measured at two voltages so far. See results here:
Notes:
- beam test data from Elham, which are of course for a different PMT (same model). Elham confirms that beam data was with a QDC calibration of 25 fC/channel; the only other setting was 200 fC/channel, which would have made the gain look even lower if we were on that setting by accident - when that setting was tried in beam data the signal could not be seen above pedestal.
- note that the bench data extrapolated to 1500 V setting would give a gain of just under 3x10^6, which is quite consistent with the Hammamatsu catalog value of 3x10^6. Beam data is lower by about a factor of 8. Could there be that much spread tube-to-tube?
- Simona will continue tests, going to lower voltages.
- Simona has a nice cosmic-ray telescope setup with finger-size trigger scintillators.
