RC Update and Run plan for Sep 15,2020
From HallCWiki
RC Meeting Information
RC Daily Meetings are M-F at 4:15 PM
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Tuesday 15 Sept 2020.
General updates
(See d2n Run Plan 2020 for broader status/overview.)
- Target work during beam studies yesterday was successful
- Replaced spectrum analyzer mounting plate. [1], [2], [3]
- Measured target field direction. [4] These measurements are consistent with Bill/Murchhana's earlier measurements. So target field angle is not the driver for lower than expected polarization.
- Rotated target to Transverse/270 -- Done [5], [6]
- Took some parasitic Carbon-Optics runs during CW portion of beam studies in Kin-A and Kin-X
- Beam handed back to us in early OWL, and continued production running in Kin-A, Kin-X at transverse/270
- Alternating between triggers T1 (1hr), T2 (3hrs); then repeating
- Lost SL 2K coldbox at 8am Tuesday morning [7]; minimum 4 hour down, cryo identified the problem but still working on repair (as of 9:15am)
- Will continue production running in Kin-A, Kin-X at transverse/270 (w/ T1 and T2 triggers) after standard beam profile checks.
Notes for the Future
- Moller measurement planned for Wednesday DAY starting at 8:30am
- Hall A's Moller will run Wednesday DAY as well. Will need to coordinate on IHWP switches.
- 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 are ongoing [Melanie]
- 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.
- 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)
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 [13]
Opportunistic Jobs/Access
- Target calibrations / tests (Particularly anything that will be needed at 1-pass!)
- Just before Moller measurement, and/or other known downtimes
- See D2n_Run_Plan_2020#Target_Calibrations_and_Tests
Current Run Plan
Tuesday DAY → Tuesday SWING
- Wait for 2K coldbox repair, and south linac to be restored
- Continue production data in Kin-A, Kin-X with pol 3He target, Transverse/270 polarization with pNMR/NMR every 5 hrs.
- NOTE: Take 1 (1hr) run with T1(3/4) trigger; then 3 runs (1hr each) using T2(EL_real) trigger; Then repeat that cycle.
- Be sure to monitor and set the prescales correctly.
- Put T1 or T2 in the CODA comments field for the runs.
- Note the T1 or T2 trigger type for each run in the Shift Summary and Run database using the
add_run_commentcommand.
- NOTE: Take 1 (1hr) run with T1(3/4) trigger; then 3 runs (1hr each) using T2(EL_real) trigger; Then repeat that cycle.
Wednesday OWL → Wednesday SWING
- Moller measurement on Wednesday DAY at 8:30am (Murchanna, Bill)
- This will also be used to infer polarization at 1-pass (if it fails, we'll try again on Thursday DAY)
- Wednesday OWL or DAY during Moller 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
-- General plan below this point is fixed, but details may be adjusted as beam/target requires --
Wednesday OWL → Wednesday 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
Thursday OWL → 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 Move to Controlled Access (w/ RadCon support) to begin transition to 1-pass
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 (had one strange hangup lately)
- 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
