GEM and Sci. data and measuurements
Counting Experiemnt using tennelec tc 534
All the counting was done by one scale tennelec tc 534.
Discriminator setup for GEM and PMT's
The counting period is 5 min for all the discriminator threshold measurements unless it is differently reported for a specific measurement.
- GEM (amplified 15) without source
| Voltage (V) | Number of Counts (5min) | Average ( /min) |
| 3.0 | 9 , 16, 26, 32, 46 | 8.5 0.5 |
| 2.5 | 62, 138, 208, 267, 329 | 66.7 3 |
| 2.0 | 259, 618 (2.5min), 767, 1001, 1241 | 253 5 |
| 1.9 | 1030, 2100, 3200, 4300, 5391 | 1002 110 |
| 1.8 | 20667 | 20667 |
- GEM (amplified 15) with source
| Voltage (V) | Number of Counts (5min) | Average ( /min) |
| 2.5 | 14,23,43,68,77 | 3 |
| 2.0 | 116,248,391,513,640 | 3 |
| 1.8 | 1674, 3350, 5037, 6680,8385 | |
| 1.7 | 22200 | |
| 1.6 | 57000 | |
| 1.5 | 349000 |
- GEM (amplified 15) without source ortec 875
| Voltage (V) | Number of Counts (5min) | Average ( /min) |
| 2.5 | 14,23,43,68,77 | 3 |
| 2.0 | 115,262,390,508,646 | 3 |
| 1.8 | 3650, 7650, 11350, 14550,17938 | |
| 1.7 | 22200 | |
| 1.6 | 57000 | |
| 1.5 | 349000 |
- PMT (R)
| Voltage (V) | Number of Counts (5min) | Average (/min.) |
| 1.00 | 87, 178, 254, 337, 430 | 86 2 |
| 0.7 | 219,410, 585, 768, 977 | 203 12 |
| 0.35 | 441, 941 (2.1min.), 1383, 1853, 2354 | 453 11 |
| 0.30 | 750(1.5min), 1012, 1551, 2050, 2573 | 509 8 |
- PMT (L) (amplified)
| Voltage (V) | Number of Counts (5min) | |
| 2.0 | 56, 110, 171, 234, 290 | 572 |
| 1.0 | 263, 484, 737, 978, 1233 | 248 10 |
| 0.6 | 497, 1055,1632, 2114, 2655 | 52420 |
| 0.25 | 945,1866,2787, 3676,4643 | 93211 |
Counting the coincidence for the PMT's
The discriminator setup is 0.7 and 1.0 V for the Left and the right PMT successively.
- Without Source
| Start Date | Time | End Date | Time | Duration (min.) | Number of Counts | Count rate (cout./s) | Notes |
| 05/08/14 | 17:55 | 05/08/14 | 11:32:00 | 325 | 27120 | 1,4 | Daylight |
| 05/08/14 | 11:32:00 | 05/09/14 | 06:26:00 | 739 | 61825 | 1.4 | overnight |
| 05/09/14 | 06:26:00 | 05/09/14 | 13:54:00 | 1187 | 99300 | 1.4 | Daylight |
| 05/09/14 | 13:54:00 | 05/09/14 | 21:18:00 | 1631 | 136290 | 1.4 | Daylight |
| 05/09/14 | 21:18:00 | 05/11/14 | 6:55 | 3648 | 301960 | 1.4 |
Counting GEM (2.7, 3.1kV)
GEM operating voltage is 2.7, 3.1V GEM and cathode successively, and the disc. threshold is 2.0 V.
- Without source
| Start Date | Time | End Date | Time | Number of Counts | Duration (min.) | Count Rate (cout./s) | Notes |
| 05/08/14 | 16:14:19 | 05/08/14 | 23:37:00 (311 from 330 less by 19) | 42903 | 311 | 2.3 | Daylight |
| 05/09/14 | 23:37:00 | 05/09/14 | 06:18:00(731) | 99196 | 712 | 2.3 | overnight |
| 05/09/14 | 06:18:00 | 05/09/14 | 13:50:00(1183) | 162485 | 1164 | 2.3 | Daylight |
| 05/09/14 | 13:50:00 | 05/09/14 | 21:21:00(1633) | 223301 | 1614 | 2.3 | Daylight |
| 05/09/14 | 21:21:00 | 05/11/14 | 06:57:00(3650) | 472100 | 3631 | 2.2 | weekend |
Counting without a source (Background)
GEM and Sci. are in coincidence, GEM detector operating voltage is 2.7, 3.1V for GEM and cathode successively, both of the PMT's have 1kV input voltage.
The disc. setup is as determined in the previous measurements, the count rate is 0.001 /min for scintillator-GEM coincidence
Counting Experiemnt using 3 scales including tennelec tc 534
GEM Counts
- Without Source
| Counting Time (min.) | Number of Counts | Count rate (cout./min.) | Notes |
| 15 | 882 | 59 |
- With Source
| Counting Time (min.) | Number of Counts | Count rate (cout./min) | Notes |
| 120 | 7390 | 60 | using the new counter ortec sophiia has only 1 cout/s |
| 120 | 16565 | 138 | change to the same counter used before for GEM ortec 875 without 2.3 count/s |
| 433 | 37865 | 87 | 1.4 count/s, overnight |
| 230 | 29618 | 1.29 | 2.1 count/s |
- increasing the voltage to 2.85 kV, and 3.45 kV
without source coicidence of the three is 25 when it counted for 283 min.
with a soruce 300 counts in 970 min. ,we may need to increase the voltage again.
Coincidence Scope pictures
First Coincidence using Widest timing gate (1 usec)
Source ON
I saw about 1 coincidence perr minute with the source
Coincidence rate with source ON
| date | Counting Time (min.) | Triple Coincidence Counts | Scint Coinc | GEM singles | PMT1 singles | PMT2 singles |
| 5/16/14 | 211.26 min | 296 (1.27 Counts/Min) | 2519870 (198 Hz) | 429886 (34 Hz) | 36822230(2.9 kHz) | 41833? |
| 5/17/14 | 1066.55 | 1531 (1.43 Counts/min) | 12724200 (199 Hz) | 2153491 | OVERFLOW | OVERFLOW |
| 5/17/14 | 503.07 | 658 (1.3 counts/min) | 5997670 (199 Hz) | 1020620 |
The average counting rate for the first two measurements is 0.85 count/min, and for the last one 0.76 count/min., so the total average is 0.8 \pm 0.02 count/min.
Coincidence rate with source OFF
| date | Counting Time (min.) | Triple Coincidence Counts | Scint Coinc | GEM singles | PMT1 singles | PMT2 singles | comment |
| 5/19/14 | 2218.08 | 550 (0.24 Counts/min) | 330763 (149 Counts/min???) | 3237254 | 5282644 | 54 3 29 | GEM out of GAS and someone may have hit stop early on the clock (Time and Tiple coinc are correct) |
| 5/19/14 | 76.37 | 14 ( Counts/min) | 99415 (Counts/min) | 24 | 158176 | 01 04 21 | GEM out of GAS, GEM HV is on 2800:2500, change scaler for PMT2 |
