The high voltage setting TOF_1300.sql by Adrian is checked with
beam. adc spectrum of left bottum 0 is not normal, however, the count
seems correct. the small pad atatched to tof paddle 1 is not functioning
properly. A quick visual inspection did not reveal the problem.
Other than the above two, everything is fine and we started data taking.
One major run 2347 was taken with 50000+ events. run 2348 was
started, short analysis showed the results from the two runs are
consistant. Can not achieve the desired statistics even for TOF_1300.sql
setting. Did not go to TOF_1500.sql.
macro tof_eff.C is used to calculate the efficiency. When Tavi left,
he was concerned that the optimal efficiency Tancredi saw the previous
shift was not real. However, run 2347 shows that the effiency for
TOF 0, 2, 3 are arround 90% level. Could not make the measurement on
TOF 1 due to the malfunctioning of the small pad. For the cuts and
counts, please see the log book.
There was a curious efficiency drop in run 2347. For events
44000-45000, efficiency could be as low as 50%. however, the efficiency
seemed to recovered for later events. Do not know the exact reason. Please
see the log book.
We also noticed that the Cerenkov rates are 100kHz for left 0,
200kHz for right 0 even with 50 40 mA beam respectively. We also did a
quick estimate of CC efficiency. It is about 50% using cc_eff.C. Richard
pointed out it would be interesting to estimate the same efficiency with
field on.
Richard Milner, Chi Zhang
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