GEM performance data graphs
histogram analysis Shutter Open - Closed
GEM detector voltage settings:
Discriminator:
Amplification:
Shutter open run 4676 took data for 44480 seconds (12.4 hrs) and Shutter closed run 4675 took data for 28638 seconds (8 hrs)
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Run 4676 :raw shutter Open ADC spectrum | Run 4675 raw shutter closed ADC spectrum |
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Run 4676 :NORMALIZED shutter Open ADC spectrum | Run 4675 NORMALIZED shutter closed ADC spectrum |
Assume that the single peak for the Closed shutter spectrum is the result of less charge being liberated by the right most peak of the shutter open spectrum due to the energy lost by the ionizing particle as it travels through the 1mm thick FR4 shutter into the ionization chamber.
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Run 4676 :raw shutter Open ADC spectrum | Run 4675 raw shutter closed ADC spectrum |
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Shutter Open - Shutter Closed Difference |
Run List1 GEM, Cathode 2.6, 2.9kV
/home/daq/CODA/CODAreader/ROOT_V5.30/V775mV792/evio2nt -fr4685.dat > /dev/null
The voltage of the Cathode is 2.9 kV and of the GEMs is 2.6 kV.
The amplifier is on x6 level fine gain which will amplify the detector signal to 33.5 times (6.56+_ 0+_ V/196 +_ 0.6mV).
Run List2 GEM,Cathode 2.65,2.95kV
The voltage of the Cathode is 2.95 kV and of the GEMs is 2.65 kV.
Run List3 GEM,Cathode 2.7,3kV
- Calibration curve
,Measurements
The voltage of the Cathode is 3 kV and of the GEMs is 2.7 kV. Without any attenuation -85 mV was the initial voltage and its equivalent charge is 1.02 nC. According this value the charge below is calculated using
Run # | discrimination level | ortec 474 amplification | Attenuation (dB) | Start Date | End Date | Shutter Position | Source | pulse snapshot picture and Comparison notes | Channel number | ADC charge (nC) | Detector charge (nC) |
5072 | 0.50 | 6 level 6 | 11 | 18:20:09 05/06 | 22:28:25 05/04 | open | off | 10Hz ![]() |
1650 , 3500 | 0.766, 1.506 | 7.7, 15.06 |
5073 | 0.50 | 6 level 6 | 11 | 22:31:50 05/06 | 06:09:58 05/07 | open | on | 10Hz ![]() | |||
5074 | 0.50 | 6 level 6 | 11 | 06:16:00 05/07 | 12:39:58 05/07 | close | on | 10Hz ![]() | |||
5075 | 0.50 | 6 level 6 | 11 | 12:45:04 05/07 | 07:58:00 05/08 | close | off | 10Hz ![]() | |||
5076 | 0.50 | 6 level 6 | 11 | 08:00:44 05/08 | 13:06:40 05/08 | open | off | 10Hz ![]() | |||
5077 | 0.50 | 6 level 6 | 11 | 13:09:56 05/08 | 20:27:39 05/08 | close | off | 10Hz ![]() | |||
5273 | 0.50 | 6 level 6 | 11 | 22:51:57 06/07 | 13:06:40 05/08 | open | off | 10Hz 90px |
Run List 4 GEM,Cathode 2.75,3.05kV
Run List 5 GEM,Cathode 2.8,3.10kV
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