From: Xu, Zhangbu (xzb_at_bnl.gov)
Date: Sat Mar 08 2003 - 10:34:35 EST
Hi,
We took 50K TOFr test trigger last night.
Bill (Llope) and Lijuan have been looking at the data.
From the trigger, 85% of the data have pVPD information
compared to about 28% without this trigger.
The 15% inefficiency is likely due to TOF daq deadtime
this is larger than expected assuming 5us fast clear time.
We can gain this back by putting local busy as a veto to
the trigger signal sent to CDB Board. This however needs
an access. I would say that we go ahead with this run
since there is no access in the next two days and I am
going to SQM03 next week.
(Can someone tell me where is the local busy signals in case
there is an access in the next two days?)
Out of this 85%, almost every event has a TOFr hit and 33%
has matched primary tracks. Without trigger, this matching
is about 0.6%.
I called Bill Christie at home this morning.
He would like to have all online monitoring plots of TOFr
ready before we start official TOFr trigger run.
Please make sure Sergey does this today.
Thanks!
Zhangbu
-----Original Message-----
From: Lijuan Ruan
To: Xu, Zhangbu
Sent: 3/8/2003 2:45 AM
Subject: Hello,The fast offline *4066046.event.root
Till now only small part of 4046006.event.root files generated.
They include 4528 events.And I also put the
http://www.star.bnl.gov/protected/spectra/ruanlj/tofr/TofrCellNumber-TPCHitZ
position-4066046.ps in my spectra/ruanlj/tofr.
Besides,everything seems normal,in the 4528 event,we have the tofr
primary match hits 1219.And we know the trigger efficiency is
5115/6208=82.4%,so only the 1219/4528/0.824=32.67% tofr hits are
from primary track.So it's consistent with the old data.
Lijuan
<<<<<<<<<<<<
..forgot to mention one other thing
this run (~50k star events) got us ~1k hits per tofr channel. (!)
thus to collect 20k hits per tofr channel from primaries
(assuming 1/3) implies we need ~3M dAuTOF-triggered events.....
cheers
--
_________________________________________________________
W.J. Llope, Ph.D. Res. Assoc. Professor
http://wjllope.rice.edu/default.html
llope_at_physics.rice.edu
T.W. Bonner Nuclear Lab.
Rice University, MS-315
6100 S. Main phone: 713-348-4741
Houston, TX 77005-1892 fax: 713-348-5215
<<<<<<<<<<<<
enhancement in local trigger efficiency is about a factor of ~3
(~28% -> ~84%)... shouldn't this be higher? zhangbu, did
you notice what the tof dead time was during this run?
enhancement in tofr hits/pvpd trigger is ~20. big effect.
_________________________________________________________
W.J. Llope, Ph.D. Res. Assoc. Professor
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