Operator: zwart
TZ on shift after a long hiatus.
Good runs 10377-10384,
Beam required lots of tuning. Finally back at ~3AM following day of snake fill. Filling to 130 mA max because of high rate in normalized right wire chamber scaler (54 at 130 mA). However things seem to be running well.
Short fill times ~21 seconds are important for best beam quality for detector.
Beam quality seems really good. Almost no WC trips. How can this be?
10 Hz seems like a better injection rate than 20 Hz. We need efficiency monitor of integrated C-line toroid vs stored charge in ring.
At ~6 AM LIGIT increases abruptly from a very flat 7e-8 baseline to a more variable baseline centered at 8.5e-8.
Timing distribution for wire chamber on right (twr) does not look "square". TWL looks normal. KD says Doug is looking into this.
At ~6AM Compton run counter seems to have lost synchronization with CODA run #. Writing red errors in analyzer log, " Rundb unknown for (a):fill:23053 flip:0." Also spike (pedestal?) clearly visible in Compton spectrum. Stopped and statrted Compton controller. Did not help. Rebooted Compton IOC, runs synchronized again, but "pedestal like" spike still present. Killed Copmpotn Analyzer window by mistake. Performed Compton start again. Application starts cleanly, but narrow peak at channel 223 still present. Peak disappears ~8:30AM.
I added CCR Coulomb meter to the EPICS displays in the counting bay. B McA has made three distinct variables, total integrated DCCT, DCCT available to exp and DCCT accepted by experiment. The red needle (DCCT on tape) is the most important for luminosity optimization.
The numbers are:
Total DCCT: 360 C/hr
DCCT available to expt: 300 C/hr
DCCT accepted by expermient: 230 C/hr
>From scalers looks like computer live is ~88%, but the ratio of 230/300 gives only 76%. The other 12% comes from target flipping? This is an "effective" dead time which should be included in the I_min calculation for ring refill. We should have EPICS calculate the optimum I_min (at least make a suggestion) for a given I_max.
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