Saturday
- identified operating wire chamber cells in the left sector which
would hold operating voltages with beam in the ring
- right sector has problem which needs access on Monday
- connected readout to TDC's, reduced live-time of TDC to 4
microsec and was able to connect several TDC's without crashing CODA
- attempts to connect all TDC's failed as CODA repeatedly hung
- looked at TDC distributions in several runs and started to debug
readout problems
Sunday
- again tried to connect as many readout cards as possible but CODA
repeatedly hung if more than 12 or the 33 total cards were connected.
- symptoms were scalar and epics streams stopping and
needing CODA to be restarted.
- very tiresome
- looked at several readout cards on the scope and saw clear
evidence for coincidences within a cell (ie possible tracks)
- lowered operating voltages to minimize random or noise hits but
still keep coincidences
- thresholds now have a noticeable effect on rates and ringing is
reduced
- multiple hits on a wire much less frequent only a few wires
record more than one hit per event
- some question whether or not CODA or TDC's are registering all
wire channels (on scope all wires firing at approximately the same rate but
CODA data shows several wires with only a fraction of hits compared to
others
- have to study code and data bit more thoroughly
Overall very successful. Need to repair several bad cards and solve
problem in the right sector but otherwise things progressing nicely
Cheers,
Douglas
26-415 M.I.T. Tel: +1 617 258 7199
77 Massachusetts Avenue Fax: +1 617 258 5440
Cambridge, MA 02139 E-mail: hasell@mit.edu
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