Hi all,
I finished the analysis of Cerenkov calibration run 57773.
The file "show_spe.ps" shows the SPE values, which will go to the database.
There are some remarks, though :
1. Channel 22 in sector 1 has no HV (Probably, it is a bad connection
of a HV cable to the Cerenkov Sector. Could be fixed(checked) only when
we'll
have forward carriage moved forward.)
2. A number of PMT's has exponential form of the amplitude spectra,
and it is difficult or impossible to guess the SPE value, - see file
bad_PMT.ps
3. One channel ( Sector 5 channel 3) has strange amplitude distribution.
His HV value (2511 V) is much higher than any other PMT, which is
usually less than 2000 V. Although the Gaussian fit shows ~150 , I am
afraid to increase HV on this PMT.
4. I tried to set SPE to be 200 channels, but although all channels are
closer to each other, the mean value is about 185-190 . HV adjustments
were based on the run 57516, October,27. The calibration run was done
when Hall was opened and magnets were OFF. May be it will be a good idea
to repeat the calibration in
"standard" condition.
- Alex Vlassov.