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    User name X. Zheng

    Log entry time 02:00:56 on June15,2001

    Entry number 63164

    keyword=Target - EPR etc.

    1:20am, EPR, #6 laser, oven 170, Pick-up coil position.
    frequency shift 45.14 KHz, polarization = 37.5%

    Since this number is quite consistent with EPR measurement at 10:00pm yesterday, we think that target polarization is stable.
    Why did NMR measurement give only 29.5% at 11:30pm yesterday? Experts (G. Cates) doesn't think that the polarization could jump up and down so quickly. And it is possible that the gradient coil caused a big effect on NMR measurement (H1 field) and the NMR calibration constant has changed. We haven't done any gradient study in the hall but one simple thing we can start today is do 3 NMRs at 5am, with gradient coil = 7A, 5A and 0A. If there is a big difference (~20%) in NMR signal amplitude then we have a good explanation for this "29.5%".

    But people are still worried about running the target in longitudinal mode. So
    1:30am turn off longitudinal lasers;
    1:32am rotate holding field from 0 to 270 degrees;
    1:40am turn on transverse lasers;
    1:50am wait for beam to take transverse data.

    2:00am All target people in the counting house (expert from UVa, local experts, and humble student from MIT) are waiting for the exciting "NMR+gradient coil" test.