RC Update and Run plan for Sep 9,2020
From HallCWiki
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: +1.408.740.7256 (US (San Jose)) +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
- NOTE: The HALLC:p (beam energy) has been drifting over the past few shifts by ~3 MeV. Yesterday, the PD (Jay) made a log-entry (14:31) to address this observation: [1]. Today, at MCC 7:45 meeting, it was agreed upon by all Halls that work would be done at the Injector (~10:00 - 11:00) in order to improve beam polarization to Halls B/C/D. This was cancelled as of 10:25 (See PD log-entry: [2]), however, as there was a sign error that lead to the incorrect prediction that polarization would increase at higher beam energy. See William (Bill) Henry's log-entry: [3] which shows that as beam energy (HALLC:p) increases, polarizartion will go down.
- Sep 08/09 Swing/Owl (yesterday/today):
- Sep 09 Day (today):
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. [9]
- NOTE2: Yesterday, B. Sawatzky noticed abnormaly high rates when beam to Hall C was OFF (during d2n temperature tests) while beam to Hall A was ON. This lead to the suspicion of bleed-through beam from A to C [10]. Follow-up entry by William (Bill) Henry shows exactly when suspected bleed-through started (~15:36, yesterday) [11]. According to Brad, the problem is not as bad as was initially thought, but will have to keep an "eye" for this during target work.
- NOTE3: Hall A will run a PITA scan scheduled for 17:00 today, and will last ~10 min. During this time, the Aq (Charge Asymmetry) will be made larger (will trigger Hall C Aq alarm). Hall A will notify C a few mintues ahead of time.
- Sep 08/09 Swing/Owl (yesterday/today):
- Junhao Chen did d2n temperature tests (~15:30 - 16:30) with Target: "Pickup Coil" inserted. The results are posted at: [12]
- At ~16:24, field was rotated from +90 to +270 deg [13].
- At ~16:36, NMR mesurement was done at +270 deg and target polarization was determined to be 33.5 % [14].
- Beam was restored at ~20:50 and beam profile checks were done [15],[16].
- At ~21:43, NMR measurement of Pol He3 (+270 deg) was determined to be 36.7 % polarization (still too low) [17]. It was decided to change to reference cell target (scraping checks: [18] and take reference cell (N2, 135 psig) to allow for polarization to increase closer to ~40 %.
- At ~05:17, NMR measurement reported 37.6 % polarization. It was decided to start (05:20) d2n Pol He3 (+270 deg) production at HMS Kin-C and SHMS Kin-Z at IHWP = OUT configuration.
- Sep 09 Day (today):
- Continue taking d2n production data at Pol He3 (+270 deg), HMS (Kin-C) and SHMS (Kin-Z). Currently, we are at IHWP = IN.
Run Plan
- Continue taking d2n Pol He3 (+270 deg) production data.
d2n List of Tasks (target work) During Downtimes
- A detailed list of target calibrations / tests that need to be done can be found at: [19]
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)
- 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.)
Recent NMR/pNMR Polarization Measurements
- Sep 08/09 (Swing/Owl):
Recent IHWP Changes
- Sep 03 (Swing, as of 19:58) | IHWP = IN
- Sep 04 (Owl, as of 04:00) | IHWP = OUT [30]
- Sep 04 (Day, as of 12:01) | IHWP = IN [31]
- Sep 05 (Day, as of 14:55) | IHWP = OUT [32]
- Sep 06 (Owl, as of 07:00) | IHWP = IN [33]
- Sep 06 (Swing, as of 22:04) | IHWP = OUT [34]
- Sep 07 (Day, as of 12:11) | IHWP = IN [35]
- Sep 08 (Owl, as of 05:05) | IHWP = OUT [36]
- Sep 09 (Day, as of 13:57) | IHWP = IN [37]
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: [38]
- 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[39]
- 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
- Spectrometer GUI (
- 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
