ccr started off by re-tuning the beam. afterwards, we used the halo
monitors to fine-tune the slits. we found the following optimal slit
positions:
l = -4, r = 7, t = 2, b = -3
with halo scintillator rates of:
t = 2.5kHz, l = 4.0kHz, b = 1.0kHz, r = 1.3kHz
we then took a few runs with 0.1sccm unpolarized hydrogen (runs 83 - 90).
we analyzed run 85 using lrc.C in order to see how many of the total
events were ep events. the answer (drum roll)... 1700/33000 = 5%.
wc data looks very clean. worried, though, about the seemingly high
percentage of events which trigger tofs in both sectors but not the wc's.
probably (hopefully), they're just cosmics...
wc boxes L7, L14, and L21 tripped periodically throughout the shift.
signal to noise ratios of 16:1 were common. currents for non-tripping
boxes were low and steady (around 0.3microamps). twice throughout the
shift one of the wc crates tripped (the entire crate), and i had to use
the "WCHVX hv on" command to revive it. weird.
by end of shift, the halo scintillator rates were beginning to rise (up to
about 3 - 6khz). maybe a re-tuning is needed for each shift???
aaron, chris, and vitaliy
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