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    User name R. Michaels

    Log entry time 00:54:22 on January17,2004

    Entry number 115904

    keyword=Comments on coinc time and T7

    Figs 1 and 2 show the coincidence time for trigger T7.
    First comment is that the way to pick out a trigger N is
    D.evtypebits&(1 < < N).   Do not use D.evtype.
    Second comment is that the online analysis GUI emphasizes T5
    since mostly T5 appear in the data with a bump. Few T7 have
    a bump. There is a hint, however, that they may be good kaons,
    but this needs further check.
    Thirdly, the L-arm measure of the coinc. time is dangerously
    close to the limit (12 bits = 4096). Since the S2m TDCs have
    a minimum value at 1500 channels, we can easily afford to add
    25 nsec to the start of the TDC that serves to measure both
    S2m TDCs and coinc. time. (Of course this requires a short
    access and would require a new timing calibration.)
    Finally, given the uncertain nature of T7 it would be wise
    to keep more T5, which we will do. Prescales adjusted.


    FIGURE 1

    FIGURE 2