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    User name R. Lindgren

    Log entry time 00:09:17 on May12,2010

    Entry number 322278

    keyword=shift summary

    19:30 4 ua in Hall A
    Megan and others are using beam to test Compton polarimeter
    Left dipole is still down
    Hareboot27 right dipole after several tries it looks like its working
    Field is fluctuating but NMR is locked???
    Jack Segal just came in
    Going to check left dipole controls and Q2 in the trailer.
    Jack says "The scope shows the NMR on the Right Dipole is locked in. The field readback is all over the map. I think we have fried a NMR meter in some fashion. If someone knows of a quirk in the meter that would do this please call and let us know. The current readback is very stable. Perhaps it would be best to set the current and just run hoping that the current readback is as accurate as we need."

    Right dipole
    Jack found May 7 screen shot and read off the RHRS
    current as 364.75. Then adjusted the set current to 361.808 until the readback current was 364.75. Since the D-N read back dipole field is fluctuating wildly, you can look at the D-G read back value which is stable -0.39080.
    At 9:30 PM MCC took the beam to retune to give Hall B more stable beam. Promise beam back in a few minutes.
    22:35
    Compton polarimeter studies ended because MCC can not do harp scan.

    Prepare for production running.
    Follow standard prescription
    Silwal is logging it in
    .
    .
    .
    No put lead target number 2 in
    Change slits back to position 13
    Rate is 43 KHz
    Beam looks good on spot
    Request 5 ua of beam. Change slits
    Now request 50 ua

    Midnight Shift change