RC meeting and Run Plan, Saturday November 20th

Daily_Meetings

RC Meeting Information

NO RC meeting on Saturday

Current RC: Brad Sawatzky

Accelerator and Hall Status

• Hall A remains in Controlled Access, but is ready for beam (see 4th pass separator comments below).
• GEM and Grinch experts have made a few short accesses for opportunistic debugging while we're down.

• 4th pass separator has prevented beam to Hall A since Wed afternoon.
  • RF Separator work was unsuccessful as of 3pm Friday. PD Update: 4th Pass IOT
  • Work on the 4th pass IOT has continued over the weekend. However, latest word is that no solution will be available until at least late-day shift on Monday (and that is still a little unclear). So, stay tuned...
  • There should expect an interruption to all Halls when OPs is ready to try bringing the 4th pass separator back online.

Plans for the next few days

• Hall A will not be receiving beam this weekend.
  • TOs must come in as planned to monitor the target and provide a point of contact in the Counting House
  • Shift Leaders have been notified that their shifts are cancelled through Tuesday OWL shift.
  • Tuesday DAY shift personnel should come in as planned. The Tuesday DAY shift leader is free to arrive at noon if he would prefer.
• We will continue with the BB and SBS configuration change first thing Monday morning.
  • Since we are in Controlled Access already, and have not received beam since the last survey, we will be able to drop to Restricted quickly that morning.
  • We will still need to ensure that HVs are off and that it is safe for Techs to work on BB and SBS.
• The configuration change to SBS-11 is expected to be complete by the end of Day shift on Tuesday.
• Depending on how stable the beam is to Hall C over the weekend, we are hoping to shift the pass change to Tuesday Swing (instead of Wed Day).
  • We plan to nail the pass change details down on Sunday (tomorrow).

Additional details in sub-section notes below.

Run Plan for When Beam Returns (Tuesday OWL or Wednesday)

• Beam restoration to the Hall
  • Start with Sieve IN or OUT?
  • Ensure target is OUT
  • GEM HVs OFF
  • SBS, BB OFF
  • All other systems should be ready to go
• After initial steer-up into Hall is complete
  • Verify beam profile with Harp scans
  • Ramp BB and SBS to production currents
  • Determine raster size and position on target
• Low current GEM runs
  • 1 uA on LH2
  • Take ____ 5 min long runs with different GEM HV settings for quick voltage scan (needs details)
  • Take 1 30 min long run with the all GEMs at standard voltages to support track reconstruction checkout
• Move to Production Running cycle
  • [UPDATE ME]

• Upcoming shift schedule issues https://misportal.jlab.org/mis/physics/shiftSchedule/?experimentRunId=GMn-2021
  • Several open TO positions starting Nov 24
  • Configuration change on Monday-Tuesday (still the plan, but watch for updates!)
    • Will plan to cancel SL shifts starting Monday DAY -- Tuesday DAY; Tuesday SWING shifts will proceed as planned for now (but stay tuned)
    • (Missing SL on Monday, but that is OK due to configuration change)

Reminders / Notes

• Role sharing between SL and TO was discussed
  • TO should support the SL wherever possible while still keeping primary focus on the target
    • Beam Time accounting; Shift Checklist tasks are low-hanging fruit
    • Suggestion is to have TO start/stop runs and maintain the Run Log spreadsheet?

• Run plan communication / documentation will be 'officially' documented on the Daily_Meetings#RC_Meetings page
  • Don has made the Run Coordinator 'Run Plan / Report' page more visible on the wiki (and nicely formatted it)

Subsystem Updates

• Hall Status:
  • Presently in Controlled Access. We will stay in this mode until Monday morning.

• HCal:
  • HCAL timing plots are being updated/corrected

• BBCal:
  • New HV settings made for upcoming BB/SBS on/off settings
    • Contact BBCal experts to load these if/when needed
  • Corrected BBCal - HCal timing plots (histogram definition errors in prior plots, now fixed)
    • plots make more sense, but more clean-up cuts would likely help -- work continues
  • working on cluster optimization (algorithm modifications in analyzer)
  • Provokar will be out of town in the near future (will be posted on the wiki)
    • Has been working on a number of 'how-to' scripts for experts (Arun, Sebastian, etc)

• Timing hodoscope:
  • working on RF alignment
  • HV instructions for hodoscope are in the wiki (and also re-posted to halog)

• Grinch:
  • Study of LED data taken under different BB+SBS conditions underway
  • Maria/Todd/Bradley will be taking some more opportunistic LED pulser data through the weekend

• GEMS:
  • GEM HV scan using cosmics will be worked on over the weekend
  • Likely still a good idea to do a (quick) 'voltage scan' with beam as well. Details TBD
    • This will be a GEM-expert driven program.
  • Work continues on calibrating/understanding the new GEM layer

• Beamline:
  • indications that the 'clock' rate used to compute rates from scaler data in each scaler crate (SBS, LHRS) need to be checked
    • clock value in analyzer likely off by a little in at least one arm
    • David F will go down into the Hall and explicitly measure the rates
    • Resolved: Clock signal rates measured here: https://logbooks.jlab.org/entry/3946822

• • David F is looking at scaler sanity checks with Paul

• DAQ:
  • Alex reports that the LHRS scalers are not gated by the Trigger Supervisor -- will look into it
    • Bob M. and David F. have responded and will be taking care of this

• Replay analysis:
  • GEM work is ongoing
  • Eric working on end-of-run report file output along with Dave F.