IAC 2-28-08
DC HV and Gas
90/10 ArCo2
| HV settings | ||
| Wire | Volts | current (A) |
| Sense | 1500 | |
| Field | -750 | |
| Guard | 750 | |
Beam tuning
- The gun voltage was turned to zero and we saw no events in the rear scintillator associated with the gun pulse. We believe there are no electrons from the cavities (Field Emission).
- The gun voltage was put 0.35 and only single electrons were seen in the PMT based on looking at the scope trace.
- The gun voltage was put 0.4 and saw 10% of the pulses may be multiple electrons were seen in the PMT based on looking at the scope trace.
- The gun voltage was put 0.45 and saw 10% of the pulses may be multiple electrons were seen in the PMT based on looking at the scope trace.
- The gun voltage was put 0.5 and saw 10% of the pulses may be multiple electrons were seen in the PMT based on looking at the scope trace.
- The gun voltage was put 0.8 and started to see increase in multiple electrons were seen in the PMT based on looking at the scope trace.
- Now turn the magnet in front of the scintillator to bend electrons away from the paddle.
The Trigger rate of Scintillator in coincidence with the paddle was
19:21:15 -> 19:26:44 gave 70 event => 70 events / 329 sec = 766 events/hour
- Now turn the magnet in front of the scintillator to bend electrons towards the paddle.
The Trigger rate of Scintillator in coincidence with the paddle was
19:32:54 -> 19:37:16 gave 164 event => 164 events / 262 sec = 2253 events/hour
We get a factor of 3 more coincidence events with the magnet bending charged particles towards the scintillator.
- Let's see if we can up the current without getting multiple events.
DC scan
Ooops set the Sense wire voltage to 1400 instead of 1500 for these runs
90/10 ArCo2
| HV settings | ||
| Wire | Volts | current (A) |
| Sense | 1400 | |
| Field | -750 | |
| Guard | 750 | |
DC preamp at 5.6 V
1/4 " diameter front collimator, long scintillator paddle after 0.6 (?) kG magnet.
Run 420: Beam 3" away from the feedthrough, Translator Motor left off
Run 421:Beam 0.25" away from the feedthrough, Translator Motor left on
Run 422:Beam 1.5" away from the feedthrough, Translator Motor left on
Run 423:Beam 0.0" away from the feedthrough, Translator Motor left on
Accelerator Noise
We saw the following intermittent noise in the beginning of the session. We did not see it during the above data runs 319-420
Ch 1: Long scintillator paddle. Ch 3: Drift Chamber Ch 4: Gun pulser
