• Main INDEX
  • Monthly INDEX
  • PREV
  • NEXT
    Make New Entry, Make Followup Entry

    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