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    User name J Udias

    Log entry time 08:04:30 on March29,2006

    Entry number 168774

    keyword=Owl shift summary

    00:00 -BB trigger rates show large spikes with the helium target.
    00:30 -Trying carbon target to make sure that the spikes are (or are not) related to the helium target.
    01:15 -Low pressure alarm. Made an entry in the logbook. Argon pressure in the Hall A tools shows negative value. Phoned Bogdan and apparently this is not a problem.
    01:30 -Carbon target again in place, at 2 muA no spikes are shown in the BB trigger rates. Switch to the helium target.
    01:45 -NMR meausrement. Target polarization is 55.9%.
    02:00 -We requested MCC to ensure BPMA-y to be near 1.4 (it has been slightly larger than 1.6 lately). Helium target has been in place for 10 minutes at 2 muA and no spikes. We want to try 7 muA but beam tripped.
    02:10 -MCC called. Beam off for 20 minutes to change a magnet. When the beam is back we see spikes even with the empty target.
    02:30 -HV in the BB DC chambers has been lowered a bit.
    02:45 -BPMB-y is -0.2. Requested MCC to set this value nearer to zero several times.
    04:10 -Acquired run #3474 with empty target because triggers in BB have changed without apparent reason. Nerses found that the HV for the shower detector was responsible for this and fixed it.
    04:15 Half wave plate is now IN.
    04:30 -Decided to call beam off, switch on BB drift chmabers and take cosmic runs for the remainder of the shift. Results are runs 3476 and 3477 (ps1=ps2=ps3=1).
    05:42 -On request of the analysis guys, increased ps1 to 50k and acquired cosmics runs 3478 and 3479.