RC meeting and Run Plan, Monday March 8th

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RC Report

• RC: Wenliang (billlee) Li, billlee@jlab.org

Summary

• RC Daily report: https://logbooks.jlab.org/entry/4145213

CW could be sent to Hall A. A & C couldn't be brought up simultaneously (there could still be an issue). He3 target was not ready due to a position switch issue. Collected 4 hours of reference Cell data (H2) overnight. Overall, we have production beam onsight, and MCC day shifters are eager to give Hall A high-quality beam. We should be back online soon.

See a comprehensive Owl operation summary by Will Tireman: https://logbooks.jlab.org/entry/4145057

Recent Issues

• 4th pass separator connector replacement: https://logbooks.jlab.org/entry/4144059
• March 7 @ 1:00 pm, we might have lost polarization due to a strange incident https://logbooks.jlab.org/entry/4144460
• March 8 @ 2:00 am, accelerator issue: it was found that the only way Hall A could run at CW with the trip is to ramp Hall C to full current and slowly bring hall A online.
  • See log entry from MCC: https://logbooks.jlab.org/entry/4145006
• March 8 @ 3:00 am, target position switch mismatch.
  • See MCC log: https://logbooks.jlab.org/entry/4144919
  • Bill Henry's diagnostics: https://logbooks.jlab.org/entry/4144919 (this need to be part of the future target installation plan)
• Target chamber door interlock.
  • Problem solved: https://logbooks.jlab.org/entry/4145291
• Some reference cell data was collected, but some issues:
  • SBS GEMs are turned off
  • PS trigger settings were set incorrectly: (coin trigger and single trigger were both set to 1)
• Carbon hole study position not reproducible:
  • Jiwan & Bill Henry made a new rule about during the target (fur NMR during optics checkout)

Current Status

• No beam, target chamber door interlock issue is been fixed
• Accelerator is up

Run Plan

• Beam restoration
  • Harp Scene
  • Spot check
• 40uA production (may be lower)

Data Collection and Polarization Status

• Currently 40%: https://logbooks.jlab.org/entry/4144898
  • Reduced since the laser is turned off for the position switch adjustment

Other Topics/Status Updates

• March 7 @ 9:00 pm, MCC did a beautiful Harpscan which got us parallel, sigma x=0.43mm, sigma y = 0.30mm, beam https://logbooks.jlab.org/entry/4144675

• Bill Henry found some interesting about the BBCAL trigger rate, and it might be related to the raster change see log entry below

https://logbooks.jlab.org/entry/4143923

• Carlos also did some diagnostics with Grinch LED and dark rate, see below:

https://logbooks.jlab.org/entry/4144159