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    User name R. Michaels

    Log entry time 11:13:19 on November 5,2004

    Entry number 135921

    This entry is a followup to: 135903

    keyword=more on qasy

    Here is a follow-up on the charge asymmetry in run 4392 (an example).
    The beam is unstable (fig 1) but we can still fit the asymmetry and
    find the different monitors are consistent (fig 2), see table of
    fitted results below.

    I modified the "qasy" script in ~adaq/qasy (see README) so that
    it looks for the ".0" file since the ".1" file is always very short.

    If the experiment wants, I can work with the source group to
    implement a feedback, it will keep qasy less than 10^-4. It may not
    be necessary for DVCS but it's something I've been wanting to do
    for the HRS DAQ for awhile now, so that it becomes a non-issue.

    Results for Charge Asymmetries
    error is the std dev in mean = rms/sqrt(N) which might be slightly
    different from the Gaussian fit but should be close.
    U3 Asy = -2155.54 +/- 41.3448 ppm
    U10 Asy = -2174.47 +/- 43.5676 ppm
    D3 Asy = -2207.81 +/- 42.5033 ppm
    D10 Asy = -2167.11 +/- 41.1224 ppm




    FIGURE 1

    FIGURE 2