The trigger GUI was not loading correctly. Adrian went down to the
D-Tunnel and did something magical (i.e. we don't know what happened) and
suddenly it worked.
A run was taken (#870), but nothing passed the trigger. Again, we went
down to the D-Tunnel. Eventually, after pulling out and re-pushing in the
MLU cables, triggers started coming out of the X-MLU. Was this a loose
cable, a cable plugged in wrong, or a flaky cable??? We don't know for
sure... If it was a flaky cable, it is either one of the ribbon cables
coming out of the L MLU or RMLU or else a cable in the patch panel itself.
Then we started taking data to compare the e-p coincidences with the
proton going in one sector or the other (the electron was required to
enter
TOF 4; the proton, TOF 13,14). Adrian analyzed run 871, containing
said events. The results were very good: coincidences in both sectors
were seen. Actually about twice as many coincidences with the proton
going to the left sector were seen than the right one. Adrian shall send
a "follow-up" e-mail containing plots of this data. In particular, look
at the ADC plots for TOFs 13,14. Both the electron and proton energy
deposits are visible.
After that, we took a series of runs (872 - 875) where we still looked for
e-p coincidences, but this time the TOFs adjacent to 4, 13, and 14 were
included. This drastically increased the trigger rate (from 40/s to about
200/s). These high rates, however, killed CODA often. (We specifically
asked for lower currents to help prevent this.) Anyway, CODA still
crapped out. So we took a bunch of runs, all with said above trigger. We
didn't have time to analyze them, however. There are around 200,000
events total in runs 872 - 875.
Aaron and Adrian
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