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User name brads/bogdan
Log entry time 00:25:38 on February 07, 2009
Entry number 259371
keyword=BB Cerenkov cabling and ADC map changes
PMTs 4, 11, 13 in different ADC
The analog signals for PMTs 4, 11, 13 from the FE amplifier have been
routed to the ADC in slot 18, channels 0, 1 ,2 respectively.
NOTE that this ADC is read-out by ROC, but requires a couple of
changes to the analyzer database to show up. First, the db_cratemap.dat
needs to have the v792 slot 18 line uncommented. Second, the db_DL.dat
and DL.BB_cer.dat (if present) need to be updated to take the ADC data
for those PMTs from the new slot/ch's.
Those signals are being passed through a CAMAC linear gate at the FE
racks. The gate is timed off T6 and is 150ns wide. The gated analog
signal was confirmed to land in the middle of the ADC gate.
Gate width on rest of ADCs changed back to 120ns (was 80ns)
The gate for the ADC in slot 17 (for the rest of the Cerenkov signals)
was restored to the old width of 120ns.
Future repair suggestions
PMT 2 looks like it has a bad base (high frequency oscillations riding
the signal). PMT 5 is just noisy (high rate of pulses).
A copy of this log entry has been emailed to: zhangyi, flay, posik, whit