RC Update and Run plan for Sep 16,2020

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RC Meeting Information

RC Daily Meetings are M-F at 4:15 PM

To join the Meeting:  https://bluejeans.com/861439920
To join via phone :  +1.408.740.7256 (US (San Jose)), +1.888.240.2560 (US Toll Free))

Wednesday 16 Sept 2020.

General updates

(See d2n Run Plan 2020 for broader status/overview.)

  • Lost SL 2K coldbox at 8am Tuesday morning [1]; minimum 4 hour down, cryo identified the problem but machine wasn't back up until late swing
    • QWP target optimization done this down [2], [3]
    • NMR @ ~41--2% with calibration constant 5.04 (Note: calibration constant is estimated).
      • Seems to be an overall improvement of a few percent. QWP work, or due to Target Oven temperature increased from 205 to 208 at 2338 on Mon [4]?
  • Continued production running in Kin-A, Kin-X at transverse/270 (w/ T1 and T2 triggers) after standard beam profile checks during OWL
  • Moller measurement planned for Wednesday DAY starting at 8:30am
    • Hall A's Moller will ran Wednesday DAY as well
    • Hall C result: 85.4% [5]; (Hall A: ~87% [6], [7])
  • HMS dipole tripped at 8:10am [8] (Current lead mass flow fault triggered by unstable recovery pressure)
    • HMS dipole PID loop adjusted by Heidi [9]
  • Setup spectrometers to Kin-C, Kin-Z (Target stays at transverse/270) [10], [11]
  • Production running in Kin-C, Kin-Z at transverse/270 (T1 trigger only) resumed around 1pm


Notes for the Future

  • 1-pass running transition scheduled for 6am Friday, Sept 18
    • RadCon is aware of the plans
    • Hall A will setup the charge-asym feedback system for us (P. King, et al)\
    • Junhao has some estimates of the NMR calibration coeffs for 1-pass 0 and 180 settings [12]
  • Melanie, Murchhana, Chao, Sylvester: please check good electron yields per Coulomb for Kin-A/X runs with T1 vs. T3 (T2)
    • Mostly complete. Early results don't show any surprises..
  • EPR calibrations cross checks [Melanie]
    • So far it all looks good, checks ongoing
    • Summary log entries: EPR(270, Kin-Z) [13], EPR(90, Kin-X) [14]
  • Bill, Murchhana check compass/field measurements
    • Also checking with Jixie re: modeled fields
    • Need to make a write-up that clearly defines all the different coordinate systems used, swapped power supply/polarity issues, etc.

Pending Issues

  • Review and do any final prep/planning for 1-pass running
    • Paddle optimization for 3He Elastic xsec running [Chao?]
    • EPR calibration for 1-pass 8.5deg setting (estimate from prior calibration?)
  • Beam energy drifts
    • Should confirm that MCC remembers to shift the energy lock to Hall C when Hall A turns off
    • Just something to keep an eye on. Has not been a problem lately.
    • Hall C 5-pass polarization goes down as energy (HALLC:p) goes up [15]

Opportunistic Jobs/Access

Current Run Plan

Wednesday DAY

  • Moller measurement on Wednesday DAY at 8:30am (Murchhana, Bill)
  • Move spectrometers to Kin-C, Kin-Z and continue Transverse/270 running there
  • Continue production data in Kin-C, Kin-Z with pol 3He target, Transverse/270 polarization with pNMR/NMR every 5 hrs when Moller complete.
    • All runs for Kin-C and Kin-Z settings use the T1 trigger only

Wednesday SWING → Thursday OWL

  • Continue production data in Kin-C, Kin-Z with pol 3He target, Transverse/270 polarization with pNMR/NMR every 5 hrs
    • All runs for Kin-C and Kin-Z settings use the T1 trigger only

Thursday DAY → Thursday SWING

  • Continue production data in Kin-C, Kin-Z with pol 3He target, Transverse/270 polarization with pNMR/NMR every 5 hrs.
    • All runs for Kin-C and Kin-Z settings use the T1 trigger only

Friday OWL

  • Continue production data in Kin-C, Kin-Z with pol 3He target, Transverse/270 polarization with pNMR/NMR every 5 hrs.
    • All runs for Kin-C and Kin-Z settings use the T1 trigger only
  • 6 am Friday Morning
    • Ensure RadCon is ready to enter Hall
    • RadCon will survey Hall and begin transition to Controlled Access
    • Stop beam, take NMR/pNMR
    • Rotate target to Longitudinal/180, switch on longitudinal lasers
      • Continue to pump in longitudinal direction until 6:30pm or so
    • Shut off lasers and lock-out fibers
      • All personnel (RadCon, Techs, and Target personnel) must attach their LOTO locks

Friday DAY

  • (Started at 6am) Open target enclosure
    • Install collimators (JP, RadCon)
    • Check on EPR photo-diode status, likely replace it? (JP, RadCon)
  • Ensure fast raster is reconfigured correctly (Expert: Jones, Gunning)
  • Rotate to minimum angles for HMS (11.7) and SHMS (8.5) (S. Lassiter, A. Comer)
  • Configure target for Longitudinal/0 or Longitudinal/180 (TBD)
  • Close up and wait for MCC to establish (1-pass) beam to the Hall

Friday SWING → Monday

  • See task list at Run Plan for 1-pass for more details
    • Initial priority will be PbPt polarization cross check with longitudinal pol. elastics.
    • These have lower priority but will likely be pursued while target spins up
      • 3He, N2 density measurements
      • H2 xsec measurement
      • Pressure curves


Standing Orders

  • Change the IHWP at least every 8 hours when running on glass cells. Call Halls A and B in advance. If there are any issues, call the RC
  • Ensure that all information in the CODA run-start GUIs is correct for every run!
  • If beam goes away for more than 3h, or MCC does operations on the beam that may change the beam tune, then move target to No Target position,
    • verify Harps scans at 3H07A and 3H07B are within spec, and
    • ensure beam is stable (with all locks ON) at 0, 0mm before continuing.
    • Beam recovery procedure has more detailed procedure if needed.
  • New beam positions have been verified and established to be (0,0) mm for all targets.
    • Monitor that beam is at (0,0) using the stripchart on the Wall screen and verify no scraping on the glass cells using the Analysis monitor.
  • Check the position locks are on.
  • Check that CODA is running normally
  • Check online replays shortly after starting runs, & full replay results too.
  • Fill BTA with realistic numbers. You may follow the guidance coming from "load from EPICS", if it does not overestimate the ABU (as it generally does). https://logbooks.jlab.org/entry/3783171. If we have to lower the beam current we actually want because the beam is too unstable, prorate the ABUs.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!                                                     !!
!!  ATTN: SHIFT LEADERS                                !!
!!     Please follow the shift summary template on     !!
!!     the laminated SL instructions.                  !!
!!                                                     !!
!!  ATTN: TARGET OPERATORS                             !!
!!  All NMR measurement HCLOG entries should include:  !!
!!     1) A title that clearly lists polarization      !!
!!     2) Screenshots of both NMR_FieldSweep and       !!
!!        the polarization fit                         !!
!!                                                     !!
!!     For an example see the following entry:         !!
!!     https://logbooks.jlab.org/entry/3768696       !!
!!                                                     !!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Notices in Effect for Shift Crew

  • Policy for CANS-related hall status change: Make a logbook entry when the hall goes in, or comes out of laser-controlled access.
  • Magnet policies
    • Follow the updated guidelines in the How-to#Spectrometer_Magnets Spectrometer Magnets How to
    • Spectrometer GUI (go_magnets) should always be visible on Shift Leader computer, hcdesk3
    • If any magnet trips, snapshot the associated power supply window and post it to hclog before resetting the interlock.
  • Monitor the beam position on target and call MCC immediately if you see large excursions (1 mm level).
  • 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 instructions are here: https://hallcweb.jlab.org/wiki/index.php/Spectrometer_Rotation#NOTICES_IN_EFFECT

Useful Links

PolHe3 Polarization Measurements

Misc Links