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    User name A. Puckett

    Log entry time 00:12:01 on April 11, 2006

    Entry number 170272

    keyword=Swing Shift Summary

    At the start, things appear to be running smoothly, no special plans for
    the shift. Current run numbers are 3818 (GEn), 13349 (Compton), 7319
    (Parity). There was a problem near the end of Compton run 13349,
    unfortunately it's too late to get a screen capture, but what I observed
    was that the Compton electron rate was very high, about 180 kHz/muA, and
    the photon and coincidence rate was nil. So I looked at the beam position
    monitor, and it had drifted far off from the set values, so I called MCC
    and they fixed the problem, they said there was a "mismatch" in one of
    the quads in the Hall A beamline. I cycled the Compton, GEn, and parity
    runs, and everything looks OK now, but be on the lookout for some junky
    data near the end of each of those runs.

    An NMR measurement at about 19:53 yielded polarization of 51.0 %.

    At maybe 22:00, give or take an hour, I asked MCC to tweak the beam
    position, it was looking good after the quad mismatch fix, but had been
    slowly drifting upward in the vertical coordinate all night, it got to
    BPMA_Y = 1.5 and BPMB_Y = 0.12, I asked them to try and nudge it down to
    1.4 and 0.0 and they did, and it looks good.

    At the end of run 3285, we plan to move to the reference cell position,
    we will have been evacuating the reference cell for about 40 minutes, and
    start to take some runs on the ref. cell, we will vary the raster size
    and record the BB DC leakage currents.

    GEn
    Run # Start Stop Nevent Replay OK? Comments
    3818 15:44 16:36 1.6M Y quad mismatch happened
    during this run near the middle of the run, BPM's drifted far from set
    values.
    3819 16:43 17:43 2.0M Y
    3820 17:43 18:49 2.0M Y
    3821 18:49 19:53 2.0M Y NMR after this run
    3822 19:57 19:58 small Y Short run for spot
    check, look good, 2x2 at target
    3823 19:59 21:03 2.0M Y
    3824 21:04 22:08 2.0M Y
    3825 22:08 23:10 2.0M Y
    3826 23:22 reference cell vacuum
    run, spot check, vary raster size
    runs 3827-3830: (see entry of Nilanga) changed raster size, observed BB
    DC leakage currents, and adjusted HV, all with empty reference cell at 8
    muA. After leaving, plan is to fill ref. cell with hydrogen and run for
    an hour, then go back to normal running.

    Parity
    Run # Start Stop Nevent Aq Comments
    7320 16:34 18:03 160K -42.6 +- 18.3
    7321 18:05 19:53 185K don't know final value but was
    small for most of run
    7322 19:57 21:34 171K -11.5 +- 16.0
    7323 21:34 23:23 191K 2.74 +- 16.56
    Compton
    Run # Start Stop S/N Pe*Pg Comments
    13349 15:48 16:24 15.7 88.8 Hall A quad
    mismatch last 9 minutes of this run.
    13350 16:29 18:03 6.6 86.0
    13351 18:04 19:32 4.5 85.6
    13352 19:32 19:54 2.7 80.8 short run,
    stopped early for NMR when GEn run 3821 ended

    13353 19:57 21:35 5.3 86.1
    13354 21:36 23:23 5.6 84.8