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User name A. Puckett
Log entry time 23:43:25 on January27,2009
Entry number 258039
keyword=shift summary
Started shift at end of beam studies. Went through usual checkout procedure for beam restoration with no trouble. BigBite wire chambers had been turned off before the start of this shift. Almost forgot to turn them back on, but did in time to start run 5633 shortly after full beam current was restored. Unfortunately, the new beam tune resulted in unacceptably high Compton background rates, so MCC tried to retune the beam to improve this. The background rates improved, but Alex could not get the cavity to lock with the laser on. So, we went back to production data taking with no Compton asymmetries. At around 9 pm, we requested a short controlled access so Brad could go work on the BigBite gas Cerenkov, specifically to change from CO2 to C4F8O. Before the access, we had run with the Cerenkov HVs off, afterwards, they were on. There was only one BigBite MWDC HV trip as of this writing. List of good runs:
Run #, start, stop, Coulombs:
5633, 17:01, 17:16, .0062
5634, 17:39, 18:27, .03178, ended with BB HV trip
5635, 18:33, 20:00, .0675
5636, 20:00, 20:29, .0210
5637, 20:31, 20:52, .01547, ended for controlled access
5638, 21:38, spot++ check @ 2 uA
5639, 21:41, 22:56, .05545
5640, 22:56, ran into night shift...