[BLAST_SHIFTS] Last Night's Shift

From: Peter Karpius (karpiusp@einstein.unh.edu)
Date: Fri Nov 08 2002 - 10:36:33 EST


Here's what I would've sent had there been no network outage:

Before Beam

RUN 2652 cosmics run to determine the neutron counter pedestals.
         The pedestals range from approx 155ch to 400 ch.

RUN 2654 cosmics run to study TOF pedestal shift and RT6, RB10.
         There seems to be a shift of 5-15 channels for most
         channels with respect to the values in the calibration
         file blast.sc_cal. The shift is not systematic however,
         as some are shifted up and some are shifted down. There
         seems to be a marked difference in a few channels like RB14,
         RB11, RB10, RB8.

Beam tuning continued for much of the shift. During this time we
continued the software effort.

At 22:20 we were given the beam. CCR had told us that they had optimized
the beam w.r.t. lifetime. But since we had no phys trigger data on this
we decided to do a slit position study. Between the slits being all the
way out and the optimal position there was approx a factor of 6 difference
in normalized rate.

Optimal slit position:L=-4, R=16, T=5, B=-6
See the logbook for details.

RUN 2655 No Gas, 230K elastic_tof_last8.settings

(not analyzed yet)

During this run the timing of the LNC LMLU input was checked against the
last 8 LTOF's. All of these TOF signals seemed to occur for the most part
within the bounds of the NC pulse (0-40 nsec jitter).

We tried putting the LNC as a 1 in the LMLU but this dropped the rate to
2-3 Hz so we put it back in x-mode and continued taking data.

RTOF4T showed no signal on scalers or scope. Checked dumb terminal and
saw that this tube draws no current. Check HV connection at next
convenience.

RUN 2657 Gas at 0.5 SCCM, elastic_tof_last8.settings still running at
shift change.

----------------------------------------------
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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