RC Update and Run plan for Sep 11,2020
From HallCWiki
RC Meeting Information
RC Daily Meetings are M-F at 4:15 PM
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Friday 11 Sept 2020.
General updates
(See d2n Run Plan 2020 for broader status/overview.)
- Production running on Transverse target (@ 90); Kin-C, Kin-Z continues.
- General plan when this is done is to complete Kin-A, Kin-X (partially done already); then move on to Kin-B/Y and/or 1-pass running as time allows.
- Moller measurement was rescheduled for today (2nd attempt); still working on it as of 3:30pm (Accelerator issues) [1]
- Target was rotated to 90 deg yesterday
- Max Target Tommy polarization @ 90 since yesterday has been 38.5% [2], but could just need more uninterrupted pump up time.
- For comparison, maximum seen with target at 90 deg last week was 44% (9/5/2020 22:56:38)
- Maximum seen at 270 was 37.5% [3]; Recent max around 36% (Thursday) [4]
- QWP optics were inspected during controlled access Friday morning and camera was re-aligned to get a better visual of the transverse QWP rotation stages [5], [6], [7]
- NOTE: There was apparently a change in the 'transverse right' software offset (associated with the home position). This would certainly affect the initial 'dead-reckoned' starting point. See https://logbooks.jlab.org/entry/3846026 for details.
- Took ~8 hours of data in Swing, early OWL on Transverse @ 90 before machine fell over
- Mike Nycz noticed that the SHMS s2Y(+/-) scalers stopped counting as of run 11247 (2020-09-03 21:00; last Thursday)
- SHMS dipole tripped 2pm Friday (lead flow fault) [14]. Reset cleanly [15]
- Hall C Techs helped us make some shim blocks for the target cell mounting jig 'V'-blocks Fri morning. This allows us to go ahead with mounting Butterball.
- Retrieved the unfinished spectrum analyzer mounting parts from the JLab machine shop and worked with Hall C Techs to complete the work Fri morning
- Parts look to be complete now, dry-fitted everything we could
- Junhao is locating the last few screws, dowels, etc that we need
- Plan is to install this spectrum analyzer collimator at next opportunity
- Needs followup with RadCon support [Brad]
Notes for the Future
- Beam Studies planned for Monday @ 10am to 6pm (including recovery), Sept 15
- RadCon will support going to CA at 10am, we can stay in CA for roughly 2 hours; OPS wants Hall C dump available after that
- Simona wants access at this time for SOLID cherenkov related work
- Target work? (install spectrum analyzer collimator if it can be ready)
- Check field at target region for 270 setting
- Want to determine field direction at the precision of a few degrees vs the alignment laser
- Bill, Murchhana check compass/field measurements
- 1-pass running tentatively scheduled for Sept 17/18
Pending Issues
- Check EPR calibrations (particularly for 270deg setting, but others too) [Melanie]
- Spectral analyzer collimator parts are complete (verify!)
- Junhao is locating the remaining screws, dowels, etc that will be needed for final mounting
- Backing plates should be painted on the inside using the high-temp 'oven' paint
- Target polarization for Tommy @ 270 is low (mid to high 30s)
- Spectrum analyzer collimator was broken at some point and present optics setup may be allowing transient light to interfere with spectrum measurement and QWP scans
- JP wonders if the field direction is off for the transverse settings (Bill, Murchhana: see note in Target group chat from late Thursday)
- Beam energy drifts
- Hall C 5-pass polarization goes down as energy (HALLC:p) goes up [16]
- Trip rates
- Hall A Limited to 140 uA to Reduce ILM0L02 Trips [17]
Opportunistic Jobs/Access
- Beam Studies planned for Monday, Sept 14 (Note date change!)
- Target calibrations / tests
- Just before Moller measurement, and/or other known downtimes
- See D2n_Run_Plan_2020#Target_Calibrations_and_Tests
- SOLID Cherenkov Test -- Access request [Simona]
- She would prefer to have access as soon as possible starting this 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.
- Preferably, this work can be done during Day Shift, but it can also be done on Swing/Owl.)
Current Run Plan
Friday DAY → Friday SWING
- (No beam since 2am...)
- Moller measurement planned for Friday DAY shift to begin around 9:30am
- Acclerator issues pushed this to 1pm
- Before handing over to Moller, the target experts will
- Take NMR/pNMR
- Take escorted access to inspect QWP situation (ended up being opportunistic access)
- Wait for Moller to complete and get production beam re-established (late-DAY, early-SWING)
- Continue production data (HMS Kin-C/SHMS Kin-Z) with pol 3He target, Transverse/90 polarization with NMR every 5 hrs.
Friday OWL → Thursday OWL
- Continue production data (HMS Kin-C/SHMS Kin-Z) with pol 3He target, Transverse/90 polarization with NMR every 5 hrs.
Standing Orders
- 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.
- 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!
- 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
