10-31-08 GEM HRRL Photon Runs
The Goal today is to observe position dependence of photons on the GEM detector
A1 -> 13
A2 -> 11
A3 -> Trig
A4 -> 2
A6 -> 16
A7 -> 8
A8 -> 5
A9 -> NaI -> B9
B1 -> ADC1A
Run 0
GEM Backgrnd.mpa
GEM HV : VDrif = 3850, VGem = 3550
HRRL : E = 14 MeV, I =0
5 minutes long
Run 1
Run1.mpa
GEM HV : VDrif = 3850, VGem = 3550
HRRL : E = 14 MeV, I =20mA
ADC 1D has clear second peak at channel 150 but ADC1 does not. Lets Observe ADC 1D as a function of position. This corresponds to GEM output strip 13.
5 minutes long
Run 2
Run2.mpa
GEM HV : VDrif = 3550, VGem = 3550
HRRL : E = 14 MeV, I =20mA
5 minutes long
I see a second peak on ADC1D but it is at channels 100 and not 150.
Run 3
Run3.mpa
GEM HV : VDrif = 3550, VGem = 3550
HRRL : E = 14 MeV, I =20mA
3 minutes long
Unplug NaI and peak resumes near 150 channels
Run 4
Run4.mpa
GEM HV : VDrif = 3850, VGem = 3550
HRRL : E = 14 MeV, I =20mA
Now turn the detector on with the beam current on and I see a peak around 150 channels again.
3 minutes long. OOOPPPs left DAQ running while we moved the detector. Only look at first 3 minutes.
Pin 13 was located 63 cm from the mounting bracket horizontal cross bar.
Run 5
Run5.mpa
GEM HV : VDrif = 3850, VGem = 3550
HRRL : E = 14 MeV, I =20mA
Now move the detector away from the photons.
Pin 13 is a distance of 22 cm from the mounting bar moved 41 cm from its original location at 63 cm