Date: 06/04/2018
Before starting this beam test we lowered the channel thresholds on ADC 3 and 4 (modules 4 and 5) from 40 to 8
The diode Ortec 571 settings are:
- Fine gain = MAX
- Course gain = 200
- Shaping Time = 0.5us
The diode Delay Amp 1457 settings are:
- Delay = 1us
- Polarity = POS
- Range = 10V
The diode quad CFD (channel 4) threshold = 196 mV
The PB-5 Pulse Generator settings are:
- Fall Time = 100us
- Rate = 10Hz
- Delay = 250 ns
- Ampl = 1V
- Pol = POS
- Pulse Top = Tail
- Atten = 1X
- Clamp = OFF
(Make sure PB-5 = ON to output pulses)
At 19:14 we started the DAQ for 5.0 MeV 7Be at charge state 2+ on target CH2 III
- Dead time = 5%
- Trigger rate ~ 1.8kHz
- Event mult ~ 22.1
- Save name = RData_1/180406181929
At 19:30 we stopped the DAQ, Real time = 00:15:53, dead time = 5%, # good events = 1936195
See attached images for an example back strip and front strip of the central S2, and also for the diode spectrum
Before finishing for the day we decided to once again try to incorporate the downstream S2 into the DAQ setup, because this should have better angular resolution than the central S2
We opened the downstream iris (actuator setting = 1.5mm)
We plugged in RAL I, II, XI, and IV into ADC 1 (module 2) channels 0 ->31, these are the first 32 channels of the downstream S2 preamp output
Even with no beam the DAQ DT = 92% with event mult = 52.0 --> still have a noise problem with the downstream S2
At 19:41 the pressures read:
- TPU1 = 3.3e-6 mBar
- TPU2 = 9.6e-7 mBar
- TPD1 = 1.5e-6 mBar
- TPD2 = 1.7e-6 mBar
- CHUP = 1.0e-5 mBar
- CHDW = 2.7e-5 mBar
The detector biases were:
- Central S2 bias = -129.9V, leak I = 18.39 uA
- diode bias = -70.1V, leak I = 0.00uA
- Downstream S2 bias = -130.1V, leak I = 2.78uA
We called it a day and at 19:45 the detectors were switched off and the line valve closed for the night |