Log entry time 21:49:39 on October 11, 2009

Entry number 294459

Run Plan (Please HALOG it if you find something strange or wrong; Call RC if the problem is not resolved within 10 minutes)

1. Take production data at 100 uA! Watch the lumi widths to see if anything changes. Please check the histograms on the online data monitor with the reference ones on the shift how-to page (http://hallaweb.jlab.org/experiment/HAPPEX/opmanual/opmanual.html#HPXStartingonlineanalysis).


2. Currently the Compton Rates are very high!
• MCC has some things they may want to either check or do to investigate the rates. Please let them do this.
  It is our highest priority to get the Compton background rates reasonable!
• The Compton experts are available to check the Compton rates during swing shift.
  Megan Friend is on owl shift.
• The Compton experts may request to take low current runs for the Compton.
  They have permission to do these tests.
• There may be a controlled access during owl shift to change the Compton FADC threshold.
  This will be conducted by Alexandre Camsonne and Megan Friend.
• If there is a controlled access, have the arm survey the beam line from the beam entrance into the hall to the region of the Compton.
• Please follow the instructions from the compton experts. The situation is very dynamic at the moment and can change from shift to shift.


3. Change the half-wave plate state when we get to 1M good pairs. Follow the instructions for doing this and running the flipper script here: http://hallaweb.jlab.org/experiment/HAPPEX/opmanual/opmanual.html#ChangingHalfWavePlate


4. Run spot++ every couple of hours and log it. Make sure the prescale factors are PS8 = 1 and PS1 = PS2 = 99999.


5. Beam Time Accounting:
• For this period of running with the Compton high rates, we cannot take useful polarimetry data with the Compton.
• Here is how we should handle the beam time accounting for this period of time (from Kent):
  • At 100 uA the beam will probably be unusable for Compton tonight, but we are accepting it as ABU.
  • We may spend time doing Compton low current runs; those will also be ABU.
  • The only thing that isn't ABU tonight is tuning, or no beam. And the usual 1 minute after beam trips for 100uA "production" running.




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Concerns

• Compton rates are too high, experts are aware and trying to fix it.
• If anyone must reset a magnet, they must make a halog entry stating which magnet on which arm, and what was wrong with it to require a reset. The word "tech" must appear in the subject line.
• Be sure that the prompt analysis is done for every run!
• The BTA program doesn't subtract any time to speak of for beam trips. Please manually subtract a full minute for each beam trip in the beam time accounting.
• Please write a detailed shift summary (including runs taken and any activities) and submit the BTA for each shift.
• Please make sure that the shift checklist is done once each shift.
• If you have to page or call someone for support, please do so from a counting house phone or it will be ignored!
• Keep a close eye on the lumi widths as we take data.
• Please continue to take runs even if there is no beam. These data can be used to determine pedestals. Please label these runs as having no beam.