====== Calibration ======
The BLM calibration is performed with a <sup>137</sup>Cs 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)

{{:hi:hi:sn34391-137cs-1275v--00000.jpg?700|}}

====== 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 [10<sup>6</sup>] ^ 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:
  * The detector is light tight
  * If the AVD is damaged
  * If there is radiation damage to the scintillator (not related to the above problem)

  - LED check with multimeter:
    * Forward bias 1.75 V
    * Backward bias, open
  - Dark counts, trigger 30 mV  :

^ HV [V] ^ I<sub>leakage</sub> [uA] ^ Counts[Hz] ^ 
| 300  | 200 | 0 |
| 1000 | 672 | 0 |
| 1500 | 1008 | 30 |

  * Visual inspection of the SCI
    * No yellowing, signs of mechanical damage on the surface.
    * Under UV, no spots
The Standard operating voltage is 1100 V, I<sub>l</sub> = 739 uA, counting rate bellow 5 Hz


====== FAIR Type  ======
   * Measurement with Micsing scope, BW 150 MHz, dT=100 ns/div, dV = 200 mV/div, trigger -104 mV 
   * The LED drive, pulse, positive, voltage is 3V, width 50 ns, rise/fall time 5 ns, frequency 1 kHz

^ 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    |