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    User name S. Beck

    Log entry time 08:08:46 on May23,2008

    Entry number 239304

    keyword=23-May Owl shift summary


    Keeping the production runs. 10uA on LH2 6cm target. DT~40%, T5~3.8KHz (E=1.192, P(Left)=0.7097GeV/c, theta(Left)=53, theta(BB)=35.0, Carbon analyzer: doors of 3" and 0.75" are closed )

    Run 1459
    Run 1460
    Run 1461 - was stopped with 4M events after we noticed the VDCs HV tripped.
    We reset the HV on the VDCs according to the instructions in the wiki (the instructions were very clear).

    1:55 - No beam due to problems with RC cavities. MCC try to solve the problem.

    As following the check list: Magnet mismatch was found on BB. (see separate entry).

    2;53 - Beam is back.

    Run 1462 - TS11 was not connected, Run was not ended properly -junk run (See separate entry). The histograms from "do_all(1462)" look good though.

    Run 1463 - Back to production. 9.6 uA, 40% DT, T5=3.7KHz.
    The data monitor vanished, therefore the run was stopped with 1.5M events (see separate entry).

    Run 1464 - Production run, 9.7 uA, 40% DT, T5=3.8KHz. 5M events.
    Run 1465 - Production run, 9.7 uA, 40% DT, T5=3.8KHz. 5M events.
    Run 1466 - Production run, 9.7 uA, 40% DT, T5=3.8KHz. 5M events.
    Run 1467 - Production run, 9.7 uA, 40% DT, T5=3.8KHz. 5M events.

    5:20 - 5:50: most of the time there was no beam due to RF cavity problems in MCC.

    Problems in data of run 1467:
    The efficiencies of FPP WCs and of BB shower blocks have reduced compare to the previous runs. VDCs' efficiency is consistent with the previous one. All HV and LV work o.k., gases are flowing normaly.
    A common reason could be the beam. Indeed- the beam spot looks very bad (see separate entry).
    MCC had troubles with RC cavity, but it was fixed and they put in the same parameters as before. They check the problem.

    We decided to continue to take data in this setting untill it is decided to move to the next position.

    6:55- Finaly - the solution was to change the raster size by a quarter of a millimeter. The beam spot looks just fine. 1x2 mm2.

    Run 1468: First ~800,000 events are with spreaded beam spot. Toal events: 1.5M.

    Run 1469: Good production run with ~3.5M events.

    Total of good events: 65M
    ------------------------------------------------------------------

    Start to prepare for next kinematic
    1) Momentum is decreased to 0.6955.
    2) HVs of BB shower blocks were turned on.
    3) We asked for 5 uA beam current.
    4) Run 1470 - taken with these conditions. 670,000 events.
    5) illuminated blocks were chosen.
    6) We redefined scalers with 10 uA beam.
    7) Can run with 12 uA. The DT~37%, T5~3.7KHz.

    Run 1472 - Beginning of production data, in kin.#3, delta=+2.