Unfortunately, although the shift is one hour longer than normal ones, I
could not get the statistics Tancredi demanded. physics rates are
typically 2 or 3 Hz at 90+mA beam and quickly degrade to lower that 1 Hz.
Over physics rate is about 0.3 Hz.
Run 2365 taken with default Cerenkov HV. After strict cuts are applied 80
events are used to extract efficiency for TOF 7. For TOF 5, the bottom
channel of the small pad never triggered. TOF 4 and 6 have 800 and 600
events which is close to the 3% goal.
LC1 display a strangely low efficiency in coincidence with TOF 7, about
15% even after a cut of TOF adc_top+adc_bot<5000. I suspect this could be
the cause of the low count in that paddle. I can not see why is that. a
script plot_tdc_ntp.C is written to do various plots wishing to find the
reason. I wish some one can continue the study and find out the reason.
Also, it is hard to determine CC efficiency without a pre dertermined cut
to select electrons. Simply require TOF ADC top + bottum < 5000 wil raise the
calculated CC efficiency. For instance for box0 from 61% to 68%, and for
box1, due to the increased presence of protons, it is from 50% to 70%.
Maybe using e-p coincident trigger would be better on this matter.
The Run plan ask the next run to start RC0. So I stopped run 2365 even
though there is not enough statistics. At about 6:40, Cerenkov HV are
raised by 10%. Run 2366 started with this setting.
Again, it is hard to determine the LC1 efficiency without a clear tag of
electron. It is hard to say if the new HV is better and I am running out
of time.
Chi
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