Log entry time 21:28:52 on April 16, 2004

Entry number 82321

Run Coordinator's Report for 15 April Swing to 16 April Swing

Summary

Significant News

• Production data taking with parity quality beam on LH2 after beam was restored to the Hall. Frequent beam trips. Energy spread in the accelerator 3*10^-5, but due to bad RF stability they were unable to repeat the measurement. MCC was planning to work on stabilazing RF during the day shift and then repeat the measurement.
• Short Hall C access to change a PMT base (opportunistic). Details can be found in log-entry number 82295
• New DMCH box seems to work fine in 120Hz mode and shows slight improvement as compared to the older one. We will continue to run with this box hopefully until the end of the run (Louis' words not mine). See Damon's log-entry (number 82286) for more details.
• Frequent IOC SE20 crashes. At 1830 MCC agrees to change the control board (see ELOG entry number 1207264). Beam was taken away at ~1815 to make the access for the replacement and restored at 2100. Continued to run on LH2 afterwards.
• Fixed a problem with a faulty SYNC cable to the LTD for Oct3&7, Det5.

Short term Plans

• Deadtime study: 3 Runs at I=20, 30, and 40 uA with interleaved FB/TED.
• Continue with LH2 production running.
• Moller/IHWP insertion/Moller every three days. This will put us on schedule to take another Moller on Sunday, but we probably will wait until after the CD-0 tour on Monday for the next one.
• Beam energy measurement next week during the day shift. Mark Jones will be present for this.

Longer term Plans

• Green block measurement during Monday's tour. This was proposed by Louis. Since we do not need target or magnet for this, but only HV and DAQ this may be something useful we could do with the time.
• Schedule for the CD-0 tour on Monday:
  08:00 Survey of Hall
  10:00 to 11:00 Tour of accelerator and Hall
  13:00 Lockup
  Please limit time in the Hall to absolute minimum. No work should be done during the time of the tour.
• A long (restricted) access is planned for next week to pump the cryo line for the magnet (Damon). Contacted PD to rearrange the beam studies schedule in order to get a 4 hr long Beam studies periond one day next week during which we can access the hall. This way we won't lose any beam time for production running. Date of access will be announced.
• Beam energy measurement of the beam into Hall C (Mark Jones).
• PMT gain calibration at 1uA (6hrs at Julie's request)

Concerns

• Frequent IOC SE20 crashes. The IOC crashes in way that makes it hard to detect: The EPICS values freeze at a non-zero value. If this happens the IOC has to be rebooted. Paul King will write a script that gives an audible alarm if the G0 BPM flatline. The run should be immediately stopped and a note put in the end-of-run comments and in the run summary that states that the IOC crached at the end of the run. After many complaints Steve finally manages to talk MCC into getting the board changed. New IOC board has still to be tested under beam conditions.
• Spikes in French electronics, possibly caused by a network problem. Paul King claims that the buffer of ROC3 may not be big enough (currently ~2sec) and could be increased up to ~3sec, but then we would have to boot ROC3 every time we change the configuration. Shift crew should also clearly mark runs with spikes.
• Det 4-15 FL was unable to hold its HV. Problem was fixed by raising the current limit from 700 to 750. See log-entry number 82232
• NA LTD errors still occurring at a small rate. Brian has generated a "HowTo" document (located on the G0 web page under http://g0web.jlab.org/manual/Electronics_manuals.html) for trouble shooting.
• Herbert voiced concerns about the length of the coil-pulsing at thye beginning of each run . See log-entry number 82271.