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

    User name R. Michaels

    Log entry time 14:21:05 on November 30, 2009

    Entry number 303743

    keyword=re: last night's Al dummy runs

    I looked at the rates in PVDIS DAQ for electron global and gas Cerenkov.
    Compared some Al-dummy runs 14333 and 14334 to a production run
    14335. The rates were

    .............................. Al ............... Prod
    electron global .... 16.2 kHz ........ 218 kHz
    Gas cerenkov ....... 35.6 kHz ........ 400 kHz

    The ratio is 7.4% and 8.9% resp.
    The expected ratio (scaling with current) is 55/110/10.4 = 4.8%
    (see PVDIS log 43, and we now think the 104 should be 10.4).
    Need to check these factors and check the Alum asymmetry.
    It's conceivable there is an acceptance effect; we could check with
    Y-target with VDCs on. I doubt it's that big, though.

    Another issue is that none of last night's Alum runs had VDC on.
    I think we can leave VDCs on throughout for these.