1. RD51 Group Saha Institute of Nuclear Physics 14 February, 2014
Triple GEM Operation
RD51 Group
Saha Institute of Nuclear Physics
14 February, 2014

2. Triple-GEM Connection
Drift (3mm)
Transfer 1 (1mm)
Transfer 2 (2mm)
Induction (1mm)
Cathode
GEM1
GEM2
GEM3
Anode
0.1M
0.55M
1.0M
0.5M
0.4375M HV
4 Readout Sectors
0.1M
0.1M
10M
2.2nF
2.2nF
1.0M
Filter
10M
10M
10M
Divider
13th RD51 Collaboration Meeting

3. Voltage Current TabulationHV
(V) I
(A)
Drift
G1T
G1B
G1
G2T
G2B
G2
G3T
G3B
G3
Gain
4750
820
4340
3550
3150
400
2330
1956
374
1141
800
341
2761
4700
811
4290
3510
3110
2300
1933
367
1134
790
344
2565
4650
803
4240
3470
3080
390
2270
1911
359
1121
781
340
2347
4600
794
4190
3430
3040
2250
1890
360
1109
772
337
2105
4550
786
4150
3400
3010
2220
1870
350
1097
764
1844
4500
777
4100
3360
2980
380
2200
1849
351
1085
755
330
1577
4450
768
4050
3320
2945
375
2175
1829
346
1073
747
326
1338
4400
760
4010
3285
2910
2150
1808
342
1061
739
322
1129
4350
751
3965
3250
2880
370
2125
1787
338
1048
730
318
948
4300
742
3920
3210
2840
2100
1767
333
1036
721
315
821

4. High Voltage Divider Connection

5. Pulse Height Spectra for 4 Readout Sectors
HV = 4450 V
Without RC filter
13th RD51 Collaboration Meeting

6. Pulse Height Spectra For Different HV
With RC filter
13th RD51 Collaboration Meeting

7. Gain Variation with High Voltage (before RC filter)
Assumed that the voltage divider configurations are same in both the cases !
No idea whether the HV in CMSGEM is before or after the RC filter !
13th RD51 Collaboration Meeting

8. Gain Variation with High Voltage (before RC filter) and Current