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    User name M Jones

    Log entry time 12:35:11 on February15,2002

    Entry number 82797

    This entry is a followup to: 82781

    keyword=revised estimate of calibration time for Ac measurement

    revised estimate of calibration time for Ac measurement
    Bogdan pointed out that the beam energy was wrong.
    current = 100uA
    beam helicity = .75
    beam energy = 3.481
    Q^2 = 4.13

    Combined efficiency of carbon and CH2 = 0.55
    Effective analyzing power of carbon and CH2 = 0.09

    The expected focal plane Px = -0.05779 Py = -0.01500
    The sqrt(2/N/eff) = 0.00068 in 24 hours of running. The would give
    about a 2% error since extracting Ac depends mainly on Px.
    The N is calculated from rate of 92 Hz for proton assuming that the
    calorimeter is position to match the hadron HRS acceptance.
    At these kinematics the ratio is 5.6 . The rate ignores radiation correction,
    deadtime and tracking efficiency so to be conservative the rate probably
    should be lower by 60%. Using that the error would go up to 2.6%.

    Please double check the results.