RC Update and Run plan for Sep 7,2020

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RC Meeting Information

RC Daily Meetings are at 4:15 PM, remote

  • Bluejeans remote connection information:
 To join the Meeting:
 https://bluejeans.com/861439920
 To join via Room System:
 Video Conferencing System: bjn.vc -or-199.48.152.152
 Meeting ID : 861439920
 To join via phone :
 1)  Dial:
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   +1.888.240.2560 (US Toll Free))
   +1.408.317.9253 (US (Primary, San Jose))
   (see all numbers - http://bluejeans.com/numbers)
 2)  Enter Conference ID : 861439920

Accelerator Status

  • Sep 06/07 Swing/Owl (yesterday/today):
    • RF cavity 2L11-1 CWWT fault not clearing. Cavity was bypassed. (17:24 - 17:48 ) [1]
    • RSEP9A and ARC9A shunt mismatch (6:12 - 8:34). [2]
  • Sep 07 Day (today):
    • As of 8:45, downtime due to RSEP9A and ARC9A shunt mismatch has been closed. Beam restored to Hall C at ~9:00
    • 9:00 MCC morning meeting update: The PD (Jay) informed accelerator beam studies (tomorrow) Sep 08 Swing 16:30 - 19:30 with beam restoration expected at ~ 20:00. MCC will not be able to support RadCon access tomorrow for Halls B/C during Swing Shift.
    • Summary of Beam Current during Sep 07 Owl/Day: [3], [4]

General Updates

  • NOTE: Mingyu Chen has updated the pNMR measurement procedure in the TO training slides. This is in response the the failure of the pNMR fitting program over the past few shifts. It was requested that this be brought up in the next RC meeting (tomorrow, Sep 07). [5]
  • Sep 06/07 Swing/Owl (yesterday/today):
    • d2n production data-taking continued during Sep 06 Swing, and at 22:04, IHWP = OUT, and will take ~8 hrs of "beam-on-target"
    • Hall C beam energy drifted 1-2 MeV since Hall A Septum magnet tripped at ~2:30 (Sep 07 Owl). The effect on beam polarization seems to be negligible at first glance, but will need to confirm with d2n spokespeople. [6]
  • Sep 07 Day (today):
    • Beam restored to Hall C at ~ 9:00. Beam profile checks. [7], [8]
    • d2n production data-taking at IHWP = OUT will resume after beam profile checks / Pol He3 scraping checks are concluded. We have collected ~358.3 min (5.97 hrs) of "beam-on-target" data as of end of Sep 07 Owl. We still need ~121.7 min. of "beam-on-target" data.

Run Plan

  • Continue to collect d2n Pol He3 data for the next few days (until notified by d2n spokespeople that sufficient data has been collected)
    • We are currently in IHWP = IN configuration as of 12:11 (today) and will continue to take ~8 hrs of "beam-on-target" data at said configuration.

d2n Lists of Tasks (target work) During Downtime

  • Upcoming Downtime: Accelerator Beam Studies Sep 08 (Swing) 16:30 - 19:30 (~ 3 hrs) beam expected to be restored at 20:00
    • Target temperature tests
      • Junhao Chen will carry out target temperature tests tomorrow during accelerator beam studies (1 hr of tests + 3hrs polarization recovery)

Opportunistic Hall Access Requests

  • Simona Malace:
    • Simona will combine all her controlled accesses into a single controlled access at the end of d2n run period (Sep 17)
    • Alternatively, she would be also be available starting from Friday (Sep 11, Day Shift), to change the gas in the Cherenkov Tank during an opportunistic controlled access to the Hall during unexpected down times. NOTE: She may not need tech support, if she can use the ladder to reach fill the tank. Need ~ 1 hr without tech support. With tech support, may be 1-2 hrs. This can only be done during the day shift.)

Recent NMR Polarization Measurements

  • Sep 06/07 (Swing/Owl):
    • NMR @ 04:00 | 41.3 % [9]
    • pNMR @ 04:00 | 67.6 % [10]
    • NMR @ 21:28 | 40.7 % [11]
    • pNMR @ 21:28 | 39.5 % [12]
    • NMR @ 02:07 | 39.9 % [13]
    • pNMR @ 02:07 | 41.7 % [14]
  • Sep 07 (Day):
    • NMR @ 07:06 | 39.5 % [15]
    • pNMR @ 07:06 | 41.0 % [16]
    • NMR @ 12:17 | 39.6 % [17]
    • pNMR @ 12:17 | 43.5 % [18]

Recent IHWP Changes

  • Sep 03 (Swing, as of 19:58) | IHWP = IN
  • Sep 04 (Owl, as of 04:00) | IHWP = OUT [19]
  • Sep 04 (Day, as of 12:01) | IHWP = IN [20]
  • Sep 05 (Day, as of 14:55) | IHWP = OUT [21]
  • Sep 06 (Owl, as of 07:00) | IHWP = IN [22]
  • Sep 06 (Swing, as of 22:04) | IHWP = OUT [23]
  • Sep 07 (Day, as of 12:11) | IHWP = IN [24]


General Reminders for Running

  • New beam positions have been verified and established to be (0,0) mm for all glass cells. Only need to check beam is at (0,0) and verify no scraping on the glass cells.
  • Make sure the raster size is correct (4--4.5mm)
  • Monitor beam parameters/configuration very often and post an entry like this at the beginning of your shift and when run conditions have changed
  • Running on cell targets: raster always ON (4--4.5mm, size will be determined by the scraping checks), orbit locks ON, current ramp rate 1 muA/sec
  • Always take 120Hz of EDTM
  • Fill the BTA with realistic numbers. If the desired beam current is not delivered prorate your ABUs!
  • Change the IHWP at least every 8 hours when running on glass cells. Call Hall A in advance to request. If there are any issues, call the RC
  • Note that the autoload of IHWP status in the Start-Run GUI doesn't work anymore so please double check IHWP setting before you accept the GUI value.

Notices in Effect for Shift Crew

  • Follow all COVID rules and regulations as well as remind each other. Additional food guild lines:
    • All food are removed from the round table. Fruit are now store in the fridge, and individually packaged snacks are store on the shelf below the coffee machine.
    • No food near the SL and TO control station. If you would like to eat something, please use the empty round table (used to store food in the past), that is now empty and sanitized.
    • New coffee guide line: it is much preferred if you can bring you mug for the coffee. During the shift if one need to drink coffee near the control station, then the coffee mug must have a lid or have some kind of cover.
  • Beam positions: [25]
  • Policy for CANS-related hall status change: Make a logbook entry when the hall goes in, or comes out of laser-controlled access.
  • Inform the RC of any access that the Target Team requires. The RC will coordinate with RadCon to make everything run smoothly.
  • Please make sure that the orbit locks are enabled and the beam does not drift from its nominal position.
  • Ramp rate lock instructions are here and added to checklist[26]
  • An new reference Cell refill procedure: New procedure
  • Magnet policies
    • Spectrometer GUI (go_magnets) should always be visible on Shift Leader computer, hcdesk3
    • Slow ramping procedure of the SHMS, go small steps to the MOL, an great example (1 hour 30 min process)
    • HMS Q1 must be ramped down in 50A steps in all cases
    • Do not ramp HMS Q2 to zero, only go to 10A and then switch off power.
    • New updates to the magnet momentum ramping procedure: https://hallcweb.jlab.org/wiki/index.php/How_to_operate_and_monitor_the_Spectrometer_Magnets
    • If any of the Spectrometers magnets trip, take a screenshot of the PSU window and check the hall for smoke or water with the camera before resetting the interlock and post it to hclog
  • When rotating the spectrometer, use HCCAM01 to keep an eye on the SOLID Cherenkov test stand when rotating SHMS (in addition to watching the live angle-cam image, etc). The updated rotation instruction can be found: https://hallcweb.jlab.org/wiki/index.php/Spectrometer_Rotation#NOTICES_IN_EFFECT
  • New SHMS matrix element

Planned Accelerator Configuration Changes

  • Hall C to 1 pass on September 17/18, Thursday/Friday
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