ramping up beam to 30 uA on Pb

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User name R. Michaels

Log entry time 09:55:28 on March28,2010

Entry number 314148

keyword=ramping up beam to 30 uA on Pb

Parity DAQ run 2349

Ramping up beam current on Pb/Diamond target #3 (bottom)

All scint HV are off !
Have done the "procedure to establish beam on target".

Raster is 10 x 4.8 (MCC units)

The gains have been approx. matched, so I write one
Lumi and one quartz ADC value.

09:26 .... At 9 uA we see 150 k on Lumi ADCs.
We need to reduce the HV there.
But we see 20K on Quartz detectors, so if anything
the HV would need to be bumped up, but we leave it.

Stop run 2349.

Reduce Lumi HV. Run 2350. Adjusting HV during this.

Here are reasonable HV that will not saturate at 50 uA,
but are not yet optimal.

1 .... 550
2 .... 540
3 .... 540
4 .... 800
5 .... 650
6 .... 650
7 .... 500
8 .... 500

Run 2351 .... Ramping up to 15 uA
Detectors are at 30 K and Lumi at 20 to 40 K (not matched
at present)

20 uA .... 40 K on dets (these are not precise numbers yet)
30 uA .... 60 K

Run 2352 .... Trying to go to 40 uA, but cannot exceed 30 uA.

09:50 .... MCC says they need to go through a procedure to
adjust ion chamber trip levels at the dump. This takes 1 hour.

Note, the cryo temperatures did not change at all.
BTW, each run has beam trips, which are convenient.