We have a stored beam through the collimator but CCR is still busy
optimizing backgrounds. So far, bqm rates around 300 or so (left)
have been obtained (with no slits) and we hope to be progressively
able to improve on that.
Vacuum levels around the ring are approaching normal levels so
we expect improved beam conditions over time. The target has been
cooled to monitor beam-related heating effects.
All shifts are ON. The first priority is to measure the rate on empty
target and compare with previous empty target runs (see runlists). I
expect that we need at least one full shift of data taking before we can
quantify actual background yields with comparable statistical accuracy.
I'll be available and on call all weekend.
Plan:
a) Take data on empty target. If necessary for an optimal BQM rate,
limit the injection current to 60 or 70 mA. Please write to Elog.
Analyze and compare yield with previous empty target runs (for both
in/out bending field). Monitor wire chambers S/N (2 shifts)
b) Measure h2 cross section at 0.1 SCCM of gas. NOTE this may require an
adjustment to the beam tune, let ccr know (1 shift)
c) Measure singles on h2. Load the coda singles configuration and download
the singles trigger (2 shifts)
d) If backgrounds have improved repeat empty target measuraments or else
measure on empty target with open slits (to see the difference in
reconstructed events). We can always use more empty data.
-- ________________________________________________________________________________ Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124 research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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