On 23/02/2018 at 13:49 we started the DAQ in list mode.
After starting the DAQ we sent the 3.45MeV 7Li beam onto the CH2 930ug/cm2 target III.
The trigger rate ~ 2kHz, event multiplicity = 6.1, dead time ~ 9%.
The DAQ save file is: /Remote_Objs/RData_1/180223135345
Checking the ADC rate histograms:
- ADC 2 Channels 0->7 Rate ~ 1e3 (channels 0 and 5 still disabled)
- ADC 2 Channel 8 dead
- ADC 2 Channels 9->31 Rate ~ 1e4 - 1e5
- ADC 4 Channels 0->15 Rate ~ 1e3
- ADC 4 Channels 16 -> 29 and 31 Rate ~ 1e4 - 1e5
- ADC 4 Channel 30 dead
- ADC 6 Channel 31 Rate ~ 8e5
Picking an S2 backstrip at random we found a proton detection rate ~ 100Hz, no high rate beam scatters were seen, as expected from the thick target. We decided to run for several hours.
We performed occasional checks during the run:
| Runtime (hh:mm:ss) |
ADC # / Ch # |
Area in region |
Ratio to pin diode (ADC 6) |
| 01:01:00 |
2/20 |
183850 |
61.47 |
| 6/31 |
2991 |
|
| 4/24 |
262051 |
87.61 |
| 01:30:37 |
2/20 |
269255 |
61.49 |
| 6/31 |
4380 |
|
| 4/24 |
377251 |
82.94 |
| 02:03:22 |
2/20 |
362581 |
58.07 |
| 6/31 |
5987 |
|
| 4/24 |
501628 |
77.40 |
| 02:30:34 |
2/20 |
437224 |
57.86 |
| 6/31 |
7277 |
|
| 4/24 |
600118 |
76.35 |
| 03:19:02 |
2/20 |
561345 |
53.80 |
| 6/31 |
9584 |
|
| 4/24 |
765584 |
71.72
|
Where the area regions used (in channels) for each ADC Channel are:
ADC 2 Ch 20: 0->552
ADC 6 Ch 31: 1302->1475
ADC 4 Ch 24: 20 ->549
The ratios use the number of counts since the previous check. The ratios are decreasing as expected, because this indicates that fewer protons are being detected during the irradiation time.
At 17:08 the DAQ was stopped at runtime 03:19:02
The DAQ monitor dead time ~ 5%. Event multiplicity ~ 6.0, # Good events = 23917715.
We checked the beam current before the chamber, FC-E0 ~ 190pA.
See attached "180223_S2FrontStrip_ADC2CH20.png" for sample front S2 strip spectrum
See attached "180223_S2BackStrip_ADC4CH24.png" for sample back S2 strip spectrum
See attached "180223_PinDiode_ADC6CH31.png" for sample pin diode spectrum |