Table of Contents

Calibration

The BLM calibration is performed with a 137Cs source. The source emits a single gamma at 661.7 keV. The source activity was 323.2 kBq as of 11.01.2019. Its serial number is AB-9020, 370 kBq when purchased.

I have used 10 s integration time and set all BLM to count 30 k. (3 kHz)

Note on the light yield. Reference Glenn Knoll 3rd edition p.235 and p226 NE102A 10 k photons per MeV. BC400 light output 0.65 of NE102A (anthrscene). Hence one can expect: 6500 photons / keV

Bellow is a spectrum taken with the HDO6104A scope when for a BLM set to count 3 kHz (in this case XP2972 34391)

XP2972 PMT History

CBS - Cathode Blue sensitivity ABS - For a anode blue sensitivity Id - Dark current

SN CBS [uA/lmF] ABS [A/lmF] HV [V] Id[nA] Gain [106] Comment
34391 12.6 10 1188 4.98 0.79 new, will be installed in TE1
29181 used, low gain, was in S07DL1R

GS06DL3U

Reason for the service: The detector counts more than 10 times compare to the detectors above, left and right of it. Will examine it if:

  1. LED check with multimeter:
    • Forward bias 1.75 V
    • Backward bias, open
  2. Dark counts, trigger 30 mV :
HV [V] Ileakage [uA] Counts[Hz]
300 200 0
1000 672 0
1500 1008 30

The Standard operating voltage is 1100 V, Il = 739 uA, counting rate bellow 5 Hz

FAIR Type

PMT S/N AVD S/N [uA] I@1500V [uA] Dark counts@1500V [Hz] Vmin[V] LED on
LA8177 2019-101 540 < 15 1.29
LA8178 2019-100 570 < 15 1.35
LA8179 2019-102 540 < 10 1.36