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    User name R. Michaels

    Log entry time 14:53:26 on March 7,2007

    Entry number 195074

    keyword=raster checks

    The raster current measurement is being checked.

    Start off with our canonical size 25.6 x 34.5 (readback in Amps).
    Run 1244 is done with a loose scint. trig. (== random) at 900 Hz.
    We see the spikes in raster current as before.

    Reduce raster by ~1/2 amplitude 20 x 28 A. Run 1245. Ok, we see
    the changes in the DAQ.

    Now leave X alone and increase Y to 34 A. Run 1246

    Next increase X again, back to 24.6 x 34.5. Run 1247

    What the above checks tells us is that the raster current is
    cabled to the ADCs, i.e. we're not looking at something crazy.
    Also when we have smaller amplitude the big peak on left size
    of L-arm is reduced (avoid the pedestal region).

    Do a pedestal run 1248 using the pedrun config. This programs
    the ADCs to have no pedestal suppression (different from having
    ped sup with ped=0). Didn't change the picture.

    Another observation: Looking at raster current on scope it is
    very uniform. Looking at X(t) and Y(t) seperately --> very much
    a triangle as it should be. Therefore the spikes are a DAQ or
    electronics problem.