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Archived Messages for CLAS_DRIFT_CHAMBERS_1997@cebaf.gov: Region One cables

Region One cables

SCHUMACHER@ernest.phys.cmu.edu
Thu, 08 May 1997 09:23:51 -0400

May 8, 1997
Dear Dave,
I'm glad to hear you are having a good time stuffing cables.
Thirty feet of cable corresponds to about 50 nanoseconds delay for the
affected signals. This is long enough to influence the timing of our
stop signal for the TDC's. I think we should ask Amrit et al to chop
those cables and remake the ends, in situ, in the hall. You list 13
cables as being too long. One trained technician can make 8 cables in a
day, as I found when we were making cables at CMU, so we are talking 2
technician days.

I was nosing around the hall last Sunday and found a bundle of
cables for Region One stashed in the space on Level One near the tagger.
I was very puzzled to find them there, and if I remember correctly they
were for sector 4. I was in a hurry, so I did not have time to see if
they corresponded to missing cables on the detector. Maybe they are the
ones you noticed are not routed. Are they still there?

Is it possible that the extra cable length accounts for the time
shifts we saw in Sector 6? How is it then, that you saw an effect in
the later runs but not in the earlier runs? I suppose if there was a
moment in the run when we trimmed the time window for the TDC's in such
a way as to cut off part of those drift time spectra, then one could
account for the abserved effect. I don't have the data to know how and
when the time windows were adjusted. Please keep the group posted.

Regards, Reinhard.