Just so everyone is clear:
1) Runs 5448-5540 will have an artificially high Cerenkov efficiency, since
a bug in the trigger (introduced 2/25, around run 5072) effectively
required us to have a Cerenkov if both TOF and neutron fired. LC0 probably
isn't really affected, since there are no neutron detectors on forward
left. So even in trigger==1, we were biasing the trigger to require a
Cerenkov.
2) I believe there is nothing wrong with the trigger since run 5837, except
that I know we accept multi-TOF events with NO Cerenkov (maybe neutron),
but we are not accepting multi-TOF WITH Cerenkov (some MLU problem I hope
to fix tomorrow). I don't think a significant fraction of our events come
from multi-TOF, but I believe Tavi will check this.
3) I believe runs 5072-5248 will show a high RCC0 efficiency (because
they're after 2/25), but those runs are BEFORE we added the right
shielding, showing that the 97% is from a trigger bias, not
shielding. Again, I believe Tavi will check this with his efficiency codes.
Karen
At 10:16 PM 3/26/2004 -0500, Electronic Log Book wrote:
>Operators: ---- ---- ----
>
>
>Hi there,
>
>Only for those interesting in Cherenkov's and trigger settings!
>This is not actually a shift summary, but rather want to report, I guess,
>some bugs in the new trigger settings! I have checked Eugene's results and
>for RCC0 for example I have got 81% efficiency also for the latest runs
>(i.e. with the new trigger settings). I have made an usefull entry in elog
>#21634 where I put some results for CC's. Please look at (those in charge,
>of course), since there are some problems, not with CC's but with the
>software/trigger settings!
>RCC0 is fine: runs in the set: 5448-5540 after shielding and gain matching
>show 97% efficiency! runs in the set: 4835-4892 before shielding show
>worst efficiency and that bug in the software when we did not see RCC0!
>But now, after new trigger settings, we've got 81% for RCC0! and worst
>efficiency for the others. I have always used trigger==1 were no CC's are
>required!
>Help me out here! :-))
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