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    User name John Watson

    Log entry time 16:09:37 on January28,2005

    Entry number 140231

    keyword=Shift Summary: Jan 28 Day Shift

    Shift Workers: John Watson (SL), Oleksandr Glamazdin (3rd), Ran Shneor/Peter Monaghan (TO)

    The plan for today is to run 12C at 10 uA until around 13:00.
    Then we will try tuning the beam through the Compton chicane to see
    if this will reduce the non-target related background (as was observed during DVCS). Also to check that tuning through the Compton Chicane is compatible with running BigBite. After tuning the Compton Chicane we will take a short "target out" run to check the background levels, and then continue with 12C at 10 uA.

    8:30 We noticed that some of the NA bars had low gain again. When the HV crate was changed, an older set of voltages was installed. Ran will be updating the channel map on the web (see separate HALog entry from Ran)

    9:00 We noticed that BPMBY was about -0.7--well outside the "< 0.3" limit indicated on the shift summary sheet. We called MCC and had them tweak the beam so BPMBY is now around -0.18. A copy of the "Hall A General Tools" screen has been grabbed in a separate HALog entry.

    Between 08:00 and 13:15, six data-taking runs on 12C were completed:

    2135, 2136, 2137, 2139, 2140 and 2141

    Each has 200k events (2138 was aborted shortly after starting because the HVs for selected NA bars were being adjusted).

    13:15 Called MCC and asked them to start tuning the Compton Chicane, and removed the target.

    14:30 Beam off for a while--Sirish Nanda will go down to Hall A to reset the motion controls for the Compton electron detector.

    14:55 Sirish returned, and at 15:00 Hall A returned to "Beam Permit" status, but beam is off because of continuing rf problems.