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    User name jroche

    Log entry time 07:10:31 on October 29, 2010

    Entry number 337292

    This entry is a followup to: 336838

    keyword="new" results for the BCM calibration

    While coding a script computing the charge accumulated during a given run, I realized that I had use the wrong reading for the upstream and downstream BCM. I actually used one of the gated helicity instead of the total readings. As a result, my previous calibration was off by a factor of 2.

    Here are the new results. Keep in mind that this is a calibration against the clock at 103.7 KHz.

    U1  coeff=41.35+/-0.15 const=-0.220+/-0.038
    U3  coeff=13.41+/-0.07 const=-0.039+/-0.016
    U10 coeff= 8.84+/-0.04 const=-0.005+/-0.009
    D1  coeff=37.53+/-0.13 const=-0.078+/-0.037
    D3  coeff=12.09+/-0.06 const=-0.008+/-0.016
    D10 coeff= 3.84+/-0.02 const=  0.003+/-0.009
    Based on these results I think we are find working with a beam current above 1 uA. Though above 2 uA is better. The script /adaqfs/home/adaq/dvcs/onlana/charge.C computes the charge accumulated during a run using the 6 bcm signals.



    Linear fits

    Residuals low intensity

    Residuals full range