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User name J. Wexler
Log entry time 08:00:39 on August25,2009
Entry number 285834
keyword=Shift summary - owl 8/25/2009
12AM - Beam still down related to ion chamber issue.
12:45 - MCC says the ion chamber issue involved the Compton ion chamber being set to trip at 100 instead of 2000. They changed it and gave us beam.
1:15 - Changing current in the magnets to the PREX tune, and the target to the thin tantalum.
1:44 - Beam on, 5 uA, no raster on the 45 deg. angled quartz PREX detector.
2:53 - Seeing only pedestal data in the PREX detector, called for access.
4:30 - PREX detector changed to the flat configuration, and the 45 deg. configuration showed a marked malfunction (see entry 285797). The trigger was examined, and the left arm was shut off to prevent overheating related to an AC malfunction earlier in the night.
5:00 - Resume beam, swept dipole to try and find proper tune.
5:55 - Called for access in order to change trigger on the PREX detector.
6:30 - Changed trigger T3 from PREX scintillator to PREX quartz detector. Also changed to the thick tantalum target.
6:50 - Commenced 5uA current runs on the thick Ta target.
7:28 - Switch to controlled access for target cooldown.
4303-4309 - 45 deg. PREX configuration tests, 5uA beam, thin tantalum.
4310-4313 - Flat PREX config. cosmic tests during access thin tantalum.
4314-4315 - Flat PREX config. with 5uA beam, thin tantalum.
4316-4320 - Flat PREX config. with 5uA beam, thick tantalum.