Operators: zwart kohlm ----
TZ/MK/AS
First part of shift is quite smooth. Good runs 2246,2247,2248,2249
Then .... we had trouble with HV system. pc-dtun1 (PC IOC for HV) reports "broken pipe error" We went to the dtunnel to cycle power to HV crate. Then we we had to reboot the epics environment on the PC.
This rewrites the HV settings to the default, 3800 for wire cambver sense wires. Wire chamber left 21 should have been operating at 3700 volts. (See Doug's earlier message) We then had repeated trips on WC L21. Lowering the voltage to 3700 still it would not stay on.
At ~5:30AM we lost communication with the ROC. Called Doug who presribed power cycle of fastbus crates which cured the problem.
At ~3AM Emily Edwards tweaks LSIT2v to reduce bqm halo levels to top ~95 from top~150 which had drifted up. Maybe this is due to changes in the residuall BLAST field on the beamline just downstream of the target?
It appears LPM 29 is non-functional. Dan should be notified about this. It still reads -.12,-.15 although Emily moved the E-beam. The Compton backscatter rate fell from 700 Hz/ma to 100 Hz/mA. Small motion of M2-X restores back-scatter rate to ~800 Hz/mA. measure 68+/-6% for positive e- helicity.
Good run 2254 albeit with WC L21 set to zero volts. We didn't check configuration and data valid on end of run gui iinterface.
Run 2255 begins with WC L 21 set to 3500, increased to 3600 @~100kevents. Then trips once later when we increase to 3625 At the end of this run we agian lose communication with ROC. The dtunnel thermometer reads 95deg F. In some places, kicker room, towatrds the bottom of the ramp the temperature is greater than 100 deg F.
TZ/AS
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