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    User name Bugg

    Log entry time 05:23:10 on October 9,2004

    Entry number 22

    keyword=Early Beam Observations

    Bugg 23:40 1 hz beam in FFTB . We see signals in Silicon detectors and CsI on scope. Beam is too irregular to make timing possible as yet. Operators cannot see beam on dump screen and will make entry to FFTB to try to adjust camera. With only a few pulses seen the unshielded silicon detector GCALOLD sees rather large background but it is much too early to draw any conclusions.
    A preliminary look at DAQ running pattern1 showed DAQ triggering at 10 Hz but beam only at 1Hz. Dont know how to change this. Will ask Vinod tomorrow.
    Operators finished in tunnel but camera view is apparently unchanged. Cannot see beam on dump.
    12:04 AM Beam not yet returned.
    12:30 beam back .Hitting something upstream PCAL signals are very large(5-10 volts while GCALOLD is about 50 millivolts. No attenuators are in.
    1:22 Operators want togo to 10Hz. We prefer that as well
    !!!! PCAL signals and all slot nine signals preceed slot nine gate by 500ns.
    Same is true for slot 10. All new silicon devices.
    For slot 11 signls preceed gate by about 300 ns.
    Dont know how to make these adjustments so DAQ information is corrupted and data runs are useless. Will have Vinod fix tomorrow morning.
    I see signals from all detectors with exception of CsI SLAC PMT.It seems to be dead
    although it is located high in the racks above cable tray and may just see low signal.
    Cannot think of anything productive to do except help operators improve the beam.
    Have informed them about large PCAL signals indicating upstream scraping which is probably the reason for the many trips. They for some reason do not have a PLIC signal to help them locate the problem.
    Beam frequently trips.
    03:00 Operators discovered that LINAC collimators were wide ope
    n. They closed them and got a dramatic improvement in PCAL signal which dropped from 5-10 volts to 100-200 millivolts. Still not great. PCAL should be absolutely
    quiet.
    04:00
    Things have improved considerably. Took Pedestal run 210 and data run 490 to see which channels were saturating. Yuri Efremenko adjusted the trigger timing for slots 9,10 and 11. We did not check CsI timing.
    Please ignore these runs. I failed to have gate plugged in slot 11.
    new pedestal run 211 and new data run 491. These runs are not running properly. The DAQ runs at 30 Hz while beam is running at 10Hz. However Yuri will take a look at data. It looks like mostly pedestals but some data.
    We need to straighten this out with the trigger and DAQ folks.
    05:20 MCC called and asked to cut us off as they were having trouble keeping our beam running. We have decided to quit for tonight.