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    User name X. Zheng

    Log entry time 19:52:08 on August15,2001

    Entry number 70746

    keyword=Target - More EPRs, latest 48.7%

    It has been noticed that EPR spectrum was noisy during the last measurement.
    I did two more EPRs trying to find the problem. First sweep was done with Vmod
    0.8V, second with Vmod 1.1V, increasing Vmod made spectrum more noisy but
    did not improve the flipping speed.

    Suggest using Vmod=0.85 Vpp for now, and slowly decrease it when polarization
    drops. If with P~43% the spectrum still doesn't look good then something in
    electronics needs to be adjusted.

    Also found the photodiode signal is -175mV (while D2 signal did not change,
    remains at ~25uV). Compared to -36mV on Monday (right after replacing
    photodiode), it is a big change, could be related to condition change in target
    position or laser alignment etc.. I don't understand it yet.

    Latest EPR polarization (0th order)
    Target @ pick-up coil

    down: freq. shift = -52.15 KHz +/- 1.25 KHz, P = -48.77%+/- 1.17%
    up: freq. shift = 51.97 KHz +/- 1.09 KHz, P = 48.60%+/- 1.02%
    down: freq. shift = -52.19 KHz +/- 1.53 KHz, P = -48.81%+/- 1.43%
    up: freq. shift = 51.91 KHz +/- 1.56 KHz, P = 48.54%+/- 1.46%

    Average P=48.7%

    Calibrate Wavetek 80 to mix the off