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    User name Jin Huang

    Log entry time 07:11:58 on April 26, 2009

    Entry number 268601

    Followups:

    keyword=Huge Polarization Loss After Field Rotation

    He3 Pol. dropped from 68% -> 26% after two field rotation before He3 elastic runs. Changing run plan to N2 pressure curve calibration

    At shift change, I was informed that there could be a huge pol. loss due to field rotation by Yi Qiang. Therefore, we decided to rotate with small steps (.5 degree) for safe.

    However, after rotation, I notice that the field sweep NMR is much smaller than my expectation. So I decide to rotate back to vertical and confirm the polarization. The vertical freq sweep shows a polarization at 25% level. Therefore, we decide to postpone the elastic run and have target pump up again.



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



    1st NMR at Vertical Showing ~70% Pol.



    Field Rotaion w/ 0.5Degree step



    NMR at Long., The signal is small



    So, I rotate target back to vertical. Pol. loss is confirmed