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    User name paschke

    Log entry time 23:53:13 on April20,2004

    Entry number 118693

    keyword=Swing shift summary




    16:05 Target screens gone white. Vince reboots the target IOC.

    16:10 John checked with PD (Maud) about beam studies which have continued
    since 9am. It is necessary for the machine to be made right, of
    course, both to keep the trip rate down and to control energy spread.
    The last estimate is that continuing work will take at least one
    hour to complete, so no beam expected before 5pm.


    16:35 Rich gas alarm, due to Jack switching a bottle.

    16:45 MCC is returning high current beam to Hall A. We started
    a run. We saw the OTR inserted: initial width was 500 um (6e-5),
    but then a beam trip, after which the width was down to 230 um
    (<3e-5). Beam position looks good in bpmA and B, and
    feedback is on. Rich gas not yet recovered. Run 2579 started,
    but beam is not yet stable.

    17:25 Beam has stabilized (7 minutes without a trip!) at 74 uA.
    OTR 1C12 sees x width of <220 um. Run 2580 started. Rich
    gas system back to spec (25ppm Oxygen contamination)


    17:55 Bodo starts warming up ep detectors.

    18:20 Left VDC HV trip.

    18:25 Beam steering again in Hall A line, trying to reduce trip rate.
    I turned off Bodo's ep detectors to protect them.

    19:15 Randy in MCC wanted to know what our preferred trade off
    between trip rate and current. I described it as pretty
    much being a duty factor calibration. He's done steering,
    anyway, so he's going to check what current we can run at
    now. I count 21 trips in the last hour, and something like
    10 minutes at 10 uA.

    19:30 Called MCC to remind them about FFB. They feel that they may get
    some reduction in trip rate by turning FFB off. I didn't
    discourage their line of inquiry, but I'm skeptical (I think they
    were too, actually). They did check the 1C12 OTR, and on
    our screen I say 220 um.

    19:50 MCC says they're done steering for now. I've re-energized
    the ep detectors to warm up.

    20:20 MCC calls to notify us that they're turning FFB back on.

    20:40 Beam has been relatively stable, 3 trips in 30 minutes, at 75 uA.

    21:20 Requested OTR energy measurement
    results look bad.
    21:35 turned off ep detectors while MCC continues to adjust beam.
    22:20 EOC brought in.

    22:40 Problem solved! Beam returns, E spread appears ok
    DAQ hung as we tried to come back up. ROC16 quit talking to CODA,
    though the IOC wasn't actually hung.

    Rebooted just ROC16, but then ROC 12 failed to download, so
    restarted coda processes and rebooted all ROCs and TSs. Serves 'em
    right, too. They had it comin'.

    22:55 DAQ ok, continued production.