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    User name paschke

    Log entry time 05:25:37 on September26,2006

    Entry number 185342

    keyword=kinematics 12c summary: various beam currents used

    kinematics 12c was taken at various beam currents. Sorry for that, but
    we were unclear on the importance of keeping deadtime <10%. Maybe
    this data set will be useful for studying deadtime corrections!

    We took the 4cm Al dummy data first (since this required
    one less target move). We used the same beam current as
    for the deuterium, since we didn't yet know what the
    LH2 rates would be.

    Al- 5204/25204 ~500k T3. 25 uA, left arm deadtime ~14%

    Then we moved to LH2, and discovered that the rates were high.

    First, I screwed up the right prescale:
    LH2- 5205/25205
    10uA, ~150k T3. left deadtime ~16%, right deadtime ~50%

    Then, the left arm deadtime was still high.
    LH2- 5206/25206
    10uA, ~240k T3 left deadtime ~16%, right deadtime ~2%

    So we lowered the beam current:
    LH2- 5207/25207
    6uA, ~460k T3 left deadtime ~11%, right deadtime ~1%

    Then we lowered it once more, so that about half the data would have
    deadtime <10%.
    LH2- 5208/25208
    4uA, ~560k T3 left deadtime ~7%, right deadtime ~1%

    We then went back to the Al, since the LH2 data had been
    taken with different beam current and deadtime:

    Al - 5209/25209
    6uA, ~400k T3, left deadtime ~4%.
    Right prescale too high, so only 300 Hz rate.