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    User name E. Schulte

    Log entry time 18:52:37 on November 05, 2007

    Entry number 212747

    Followups:

    keyword=Warming the ESR heat exchanger and the energy change

    Because the ESR heat exchanger & cryo return line to the CHL must be
    warmed up for de-icing the Hall A targets will be warm for a few days.

    Starting today at 15:00 the helium target has been unavailable. This is
    to reduce the flow from CHL to the Hall.

    The hydrogen and lead targets are available until Day shift tomorrow
    (11/6). Early in the day shift (08:00 to 09:00) the rest of the targets
    will be warmed up. After this time both the solid targets & cryo-targets
    will be unavailable for at least 2 days (not before sometime on Thursday).

    The cryo-group has requested not fewer than 2 days to de-ice the equipment.

    We have requested that the energy change currently scheduled for
    Wednesday (11/07) be shifted to Friday (11/09):

    Hall C has reluctantly agreed.
    Hall B has been non-committal. Their Run Coordinator states that he
    cannot tell us anything until they receive beam later today. They are
    commissioning. If they are still commissioning, they may be willing to
    push the energy change. Otherwise they will be oppose, since we will
    both want 2 Pass at the same time (Hall A & Hall B). They also reject to
    requesting a pass change on a Saturday, for philosophical reasons. The
    most recent pass change may support this philosophy...

    While the hall cannot use the targets, several beam-related studies can
    be accomplished. The plan is as follows at this time:

    Perform the following studies during the day tomorrow after Target Group
    is finished warming up the targets and the Hall is back in Beam Permit
    (as time permits):

    1) Current Calibration
    2) Bulls-eye Scan
    3) Figure out if the harps for the ARC scan are working
    4) Work on Compton

    At about 14:00 A. Saha to perform an ARC energy measurement lasting about
    2 hours.

    Wednesday (11/07):

    1) Perform survey of spectrometers as planned.
    2) Find out if harp 1H03B needs to be surveyed and see if the surveyers
    can perform the survey while they're in the Hall (worked out on Tuesday).
    3) Work on compton if time permits & it still needs work, etc.

    Thursday (11/08):

    1) Cool down targets
    2) Resume data taking at 4-Pass (2 GeV, if everyone is amenable)
    -or- Resume data taking at 1 Pass at 800 MeV/pass as in the current schedule
    -or- negotiate something else.

    If we do in fact have the energy change for Friday we will come back on
    Friday at 2-Pass, with the pass change from 2-Pass to 1-Pass on Saturday
    (the current schedule shifted by 2 days).

    A copy of this log entry has been emailed to: jpchen@jlab.org, kees@jlab.org, choi@jlab.org, eschulte@jlab.org