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    User name R. Michaels

    Log entry time 01:59:04 on July21,2005

    Entry number 148842

    keyword=sweeper on/off runs 2195, etc

    Raster is about 7x7 (reality).
    Momentum P_Left = 2.736 GeV, P_Right = 2.732 GeV
    Helium target.

    Run 2195: Sweeper is OFF. 1M events
    (it was on for all the other earlier runs tonight).

    Run 2196: Sweeper is ON. 1M events

    After this we follow the checklist and switch back to HAPPEX DAQ
    mode. We have completed the steps through #9 of the run plan
    in halog 148759.

    Online analysis of these two runs reveals: a) The data was ok,
    and 2) Between sweeper on & off there is an approx. 1 MeV change
    in the average momentum -- see fig 1. I made the L-arm with
    colors and the R-arm without, to try to be clear. Also, the
    the L-arm and R-arm qsq distribution (which in absolute terms is
    not yet meaningful but the relative change has some meaning)
    changed by 1.0 & 1.6% for L-arm & R-arm respectively. The
    conclusion is that it is important to do the "final alignment"
    with the "final sweeper" setup, which is presumably 111A.
    The main thing: the two are tied together.

    FIGURE 1