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    User name brads

    Log entry time 20:53:04 on April 29, 2008

    Entry number 235852

    keyword=Run 4399 has 20% true deadtime (vs. 3% from datamon) -- don't be fooled by datamon

    Just did a quick 20k event replay of run 4399. It reports we are 20% dead vs. 3% from datamon. The 20% is reasonable for 1200Hz and a 200us readout time.

    This is the usual (and well understood) error in datamon arising from best-guesses of correlations between the triggers. It is particularly tricky in this experiment since the correlation between the dE and E plane triggers can change significantly as a function of the kinematics.

     ------------ THaNormAna Scaler Summary   ----------------·
    Time of run     0.23 min·
    Triggers:     1 = 4402747    2 = 7946585    3 = 362104   4 = 10221    5 =
    10202
    Accepted triggers:                      16083·
    Accepted triggers by helicity:    (-) = 7886    (+) = 7892
    Charge Monitors  (Micro Coulombs) 
      Upstream   BCM gain x1    47.99     x3    47.86     x10    85.19
      Downstream BCM gain x1    48.28     x3    48.33     x10    48.46
      
    
     ------------ THaNormAna Trigger Summary   ----------------·
    Trigger      Prescale      Num evt        Num in        Livetime
    ---           Factor       CODA file      Scalers       
       1            32000           127       4402747         0.742
       2            58000           131       7946585         0.769
       3             2700           131        362104         0.785
       4               76           138         10221         0.825
       5                1         10011         10202         0.789
       6                1         15983         16424         0.783
       7             2200           133        299193         0.786
       8              100           146         14279         0.822
       9                1             5             0         0.000
      10                1             0             0         0.000
      11                1             0             0         0.000
      12                1             0             0         0.000