hi everyone,
first 3/4 of shift was dedicated to wire chambers. turned BLAST field
off in order to do an efficiency study using trigger similar to
LTOF2_eff.settings. took data in this fashion until about 10pm.
perhaps wire chamber people can give more deails on the results of these
studies?
between 8 and 10 pm there was some trouble getting good beam. for most
of an hour between 9 and 10 we took no data while CCR worked on the
problem. after 10pm the beam was beatiful.
in the meantime i replaced the TOF tdc cables with the new longer cables
that were left in the D tunnel.
after 10 i took TOF efficiency data for paddles 2 and 4. i compared run
1772 (TOF2 eff. run from tonight with new cables) to run 1715 (TOF2 eff.
run from friday night, same trigger) and thethe tdc mean has indeed
shifted by about 1540 tdc channels, or about 77 ns. also the efficiency
seems to have gone up. in 1715 the TOF2 efficiencies were 94% and 95%
for top and bottom, respectively. for the new cables the efficiencies
are both above 98%. the efficiency for TOFL4 was bad: < 80%, but i
expect this is a problem with geometry or my trigger and not the
paddle. perhaps chris can look into this tonight (?)
noticed that some tubes were behaving funny. they would stop counting
so they looked dead, but after going to standby and then 'run' again,
the tubes would start counting. the tubes that did this at some point
during the shift were:
LTOF top: 2,9
RTOF top: 0,3,8,9,10
RTOF bot: 7
JS
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