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    User name Chiranjib

    Log entry time 15:03:31 on November 15, 2008

    Entry number 249006


    keyword=EPR Calibration/ SPIN UP for TRANSVERSE + / POLARIZATION etc.

    I did an EPR calibration after the spin up is done for 230C with
    Transverse pumping. The plots are attached. The polarization at this hour
    is 65.5% and the calibration constant is 1.49501.

    Actually I destroyed the polarization to some extent while making EPR
    AFP work. With the current lock in sensitivity of 1mV and FM deviation
    100Khz/V, it seems its really hard to lock the signal at all. May be its
    because the polarization is too high. Note that the PI Gain is 0.13
    (absolute) at that point and the RF amp was -7dBm.
    Then I increased the lock in sensitivity to 2mV and it still did not
    work. And then I decreased the RF amp to -10dBm and increased the FM
    deviation to 120 KHz/V. It worked fine after that.

    On the other hand , a spin up plot for the transverse + shows 4.44
    hours of spin up time .
    The max NMR expected is ~47.75mV.

    So *naively* speaking our maximum polarization could be
    * 71.4% *

    A copy of this log entry has been emailed to: jpchen,yqiang

    EPR FM sweep

    EPR AFP sweep

    POLARIZATION / Calibration constant

    SPIN UP @230C / TRANSVERSE +/75 W