Aaron's idea may explain the cause of the tripping problem but the
bottom line is the BQM rates. If these are high then the chambers and
other detectors will trip whether the slits are in or not.
Whenever something trips look at the BQM's. Often you can see a spike
in the BQM trace and if the rates have increased significantly maybe
you need to re-tune the beam.
Currently, good tunes have BQM rates of around 170, 30, 40, and 30 for
top, left, bottom, and right. If you don't have this turn off the
detectors (except BQM's) and let CCR try for a better tune.
It is important to have the detectors off while tuning the beam.
Tuning dumps lots of charge into the wire chambers and this takes time
to dissipate. If the chambers are on the wire chamber fields trap the
charge and it takes even longer to dissipate leading to poor signal to
background ratios.
Cheers,
Douglas
26-415 M.I.T.
Tel: +1 (617) 258-7199
77 Massachusetts Avenue Fax: +1 (617)
258-5440
Cambridge, MA 02139, USA E-mail:
hasell@mit.edu
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