Difference between revisions of "GEM HV Scan Runplan"
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**Prescale all triggers away except for T5 | **Prescale all triggers away except for T5 | ||
**Ask for 200nA of beam | **Ask for 200nA of beam | ||
− | **Adjust beam current such that T5 rate is ~ | + | **Adjust beam current such that T5 rate is ~200kHz |
**VDCs are ON | **VDCs are ON | ||
**GEM HV On to low HV value (given below) | **GEM HV On to low HV value (given below) |
Latest revision as of 13:12, 19 April 2010
Draft HV Scan Runplan
- Setup
- Ensure sieve is out for left arm
- Move target to thin Carbon Target
- Set Left HRS magnets to fill the focal plane: Turn off p0 regulation to the quads, cycle Q2/Q3 if going to higher momentum and set to the following currents:
I (A) | |
Q1 | 800 |
Q2 | 458 |
Q3 | 423 |
- HV for upper scintillator is on
- Left arm - LeCroy HV GUI, Card 2, Channel 10 (-1400V)
- Right arm - telnet hatsv3 port 2005, Card 9, Channel 6 (-1400V)
- Prescale all triggers away except for T5
- Ask for 200nA of beam
- Adjust beam current such that T5 rate is ~200kHz
- VDCs are ON
- GEM HV On to low HV value (given below)
- HV for upper scintillator is on
- Scan
- Scan the HV settings for the chamber as given in the table below
- Take 200k events at each step
Chamber | Low HV | High HV | Step size |
UVA | 3400 | 3800 | 40 |
INFN | 3600 | 4200 | 60 |
- Backout
- VDCs Off
- Trigger Scintillator off
- GEM HV Off
- Set LHRS back to PREX tune B: cycle quads if going to higher current, turn p0 regulation for 3 quads back on