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    User name R. Michaels

    Log entry time 15:57:23 on October21,2001

    Entry number 74905

    keyword=BPM readout modification

    Today I modified the readout of the Struck 7510 "burst mode" ADCs
    for BPM/raster. Purpose was to reduce the phase jumps observed
    between different ADCs. (About which e00102 probably doesn't care.)
    I increased the frequency by a factor of 2.5, going from 4 microsec
    per clock cycle to 1.6 microsec. Then I skip every 2nd buffer location
    and read 4, thus sampling ~1/5 of the rastered orbit. (Yes, e00102
    does not raster for most of its data.) Previously we read 6 samples, so
    it should be checked that software like ESPACE does not complain.
    Should be ok since the number of samples is written as part of a header
    to be decoded. The deadtime was reduced (75 instead of 90 microsec).
    I looked at rastered current, and saw typically 1/5 of the sine wave.
    I cannot easily verify that we solved the phase jumps until we get beam.