I ran cosmics today to test a new trigger cable and the new XMLU patterns
in physics.settings (see elog entry ). Here are the approximate rates I
was seeing:
Scaler PHYSn Rate (Hz)
--------------------- --------------
0 1
1 0
2 1
3 35
4 <1
5 400 (<1Hz in CODA since prescaled
6 500 by 1000)
FLASH 1
PHYS3 is the trigger for 2 TOFs in 1 sector, 0 TOFs in the other sector,
Cerenkov and neutron are "don't care". Before yesterday, this trigger
REQUIRED a neutron in the 0 TOF sector, so the cosmic rate would have been
non-existent.
If PHYS3 is counting too fast with beam (>100Hz?), and creating high dead
time for the other triggers, it can be prescaled or the neutron requirement
can be reinstated (but that might eliminate some interesting events?).
To prescale you need to change the Trigger Supervisor readout list:
dblast07> cd ~/pro2003/coda/crl
dblast07> emacs ts2_pro2003_pri_all8.crl
Find ts->prescale[3]=0;
Change 0 to whatever you need -- prescale factor is 1+ your number.
dblast07> source ~/pro2003/coda/coda_user.setup
dblast07> ./makelist ts2_pro2003_pri_all8.crl 68k ts2_pro2003_pri
(to build the object code)
On RunControl, end the run, then click Abort, Configure (choose physrun),
Download to pick up the new Trigger Supervisor readout list.
To add the neutron requirement to PHYS3, edit
~/pro2003/trigger/physics.settings, find the XMLU lines where the 4th
output bit is set, and remove the lines that have the 7th-12th input bits
all 0 or the 1st-6th input bits all 0 (i.e., where one of the sectors had 0
TOFs fire and 0 neutron fire). Then reload the trigger and download it:
dblast07> cd ~/pro2003/trigger
dblast07> trig physics.settings
Karen
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