Shift started with troubleshooting ADC problems which were resolved and
seemed to have a cable problem as a root cause.
Checked ADC gate versus analog signal - there seemed to be no timing
problems
Run 2203 - good ADC cosmics run
Noticed RTOF16TOP lost signal when Blast Field turned ON
we turned this tube off for remainder of shift.
Beam on just after 2115 began slit/rate studies
No Gas, Slits Out
saw approx 1:1 ratio for phys trigger:beam current
Gas @ 1SCCM, Slits Out
saw 2.5:1 ratio for phys trigger:beam current
Slit opimization by CCR began until slits were just at the border of
affecting lifetime
Optimal Slit position: L =-4, R = 15, T = 5, B = -11
No Gas, Slits optimized
saw ~1:6 ratio for phys trigger:beam current
Gas @ 1 SCCM, Slits optimized
saw ~1:1 ratio for phys trigger:beam current
(since slits were optimized per runplan we proceeded with ep studies)
RUN 2205 anycoincs.settings 20K not analyzed yet
RUN 2206 (still in progress)
changed trigger to new_elastic_tof_12-15.settings and set up XMLU output
bits so that we had separate readouts for left electron ep and right
electron ep. Scaler rates showed a slight asymmetry in that there were
approx ~1.5X more events for electron right However, recall we turned off
RTOF16TOP because of the field killing the tube signal. This removed this
TOF from the trigger (lowering the chances for an electron left ep)
----------------------------------------------
Pete Karpius
Graduate Research Assistant
Nuclear Physics Group
University of New Hampshire
phone: (603)862-1220
FAX: (603)862-2998
email: karpiusp@einstein.unh.edu
http://pubpages.unh.edu/~pkarpius/homepage.htm
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