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User name R. Michaels
Log entry time 01:18:36 on December20,2008
Entry number 254097
This entry is a followup to: 253910
Followups:
- 254102 12/20/08 02:28 R. Michaels R-HRS Cerenkov.
- 254119 12/20/08 04:47 R. Michaels PVDIS parasite tracks
For PVDIS parasites only ...
In my list of detector issues I forgot to mention Cerenkov.
The status is show in fig 1 for run 20220 taken tonight at
P0=0.2 GeV the currently favored setting on R-HRS.
There are clearly very few, if any, electrons. (I think the
expected rate was 10^-3 Hz). The PMTs labeled 2,3, and 6
below seem to be only pedestal, so maybe there's a problem with
those PMTs or cables. I think we'll need at least a few Hz of
electrons spread across the focal plane to tune up the detectors,
i.e. to set and match gains.
1-pass quasielastic might be best. My rough estimate is the
rates may be a few Hz (needs to be checked). Also QE tends to
fill the focal plane, which we need.
I'll let run 20220 go several hours, though it's of dubious value.
FIGURE 1
