RC Meeting and Run Plan, Wednesday, February 13th 2020
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RC Daily Meetings are at 4:15 PM, 2nd floor Counting House Meeting Room
Wednesday 13th Feb. 2020.
General updates
- Around 6 pm, Feb 12th, 2020 completely backed out of Moeller. 87% polarization. [1]
- Data taking at SHMS=-3.4 GeV, HMS=-3.5 GeV with reference cell, empty and N2 runs are completed.
- Accelerator issues: Vacuum VIP1L07B bad cable and cavities 1L04 and 1L12 refused to go in HV. Beam was gone between 8:45 pm - 3:00 am.
- Severe beam quality issue over the owl shift started with ion chamber tripping during reference cell N2 runs. [2] [3] [4] [5] [6] [7] [8]
Pending problem
- Beam quality issue. [9]
Fixed problem
- SHMS Dipole threw interlocks twice during the day shift. Resets were successful.
Recent polarization measurements
Current Run Plan
- Tentative plan until we're ready for production running. Give target people priority for their studies.
- Take ref. cells data at -3.4GeV/-3.5 GeV SHMS/HMS momenta:
- Ref. cell should be empty, if not pump cell to empty
- Take 2h beam-on time of Ref. Cell empty runs at -3.4/-3.5 GeV with 30 uA.(charge goal of 200mC).
- Fill with 145 PSIA (10atm) of N2.
- Take 40min beam-on time of Ref. Cell N2 runs at -3.4/-3.5 GeV with 30 uA. (charge goal: 67mC).
- Vent the ref. cell and then fill with 145 PSIA (10atm) of H2.
- Take 2h beam-on time of Ref. Cell H2 runs at -3.4/-3.5 GeV. (charge goal 200mC).
- 1h beam-on time (100mC charge goal) on "Carbon Optics" (not Carbon Foil, not Carbon Hole), 40uA with raster 0.5mm diameter.
- Restore raster size to 4mm.
- Change the spectrometer settings to SHMS=-2.6 GeV, HMS=-2.9 GeV
- Take ref. cells data at -2.6GeV/-2.9 GeV SHMS/HMS momenta:
- Ref. cell should be filled with H2 from the previous setting.
- Take 1.0h beam-on time of Ref. Cell H2 runs at -2.6GeV/-2.9 GeV with 30uA.(charge goal of 100mC).
- Vent and pump the cell to empty.
- Take 0.5h beam-on time of Ref. Cell empty runs at -2.6GeV/-2.9 GeV with 30 uA.(charge goal: 50mC).
- Fill the reference cell with 145 PSIA (10atm) of N2
- Take 40-min beam-on time of Ref. Cell N2 at -2.6GeV/-2.9 GeV. (charge goal 67mC).
- 0.5h beam-on time (50mC charge goal) on "Carbon Optics" (not Carbon Foil, not Carbon Hole), 40uA with raster 0.5mm diameter.
- Start taking data with Polarized 3He
- Spectrometer settings: SHMS=-2.6 GeV, HMS=-2.9 GeV
- Target: polarized 3He
- Target spin: longitudinal
- Raster 5mm, always ON
- ps1=0, ps2=ps3=ps4=ps5=ps6=-1 on BOTH SHMS and HMS
- Ask for 30 uA and take 1h runs. Do NMR measurement every 5 hours.
- If beam goes away for more than 2h, or if during the downtime, MCC does operations that may change the beam tuning (except work on transport magnets), then do beam recovery procedure (do YAG viewer part only if your are suspicious of the harp scan results)
- Make sure all the beam specs are followed (e.g. no raster size below 4mm on 3He cell).
- Always take 120Hz of EDTM
- 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).
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! !! !! 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 !! !! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Future
- General idea: if target polarization is about equal for transverse vs. longitudinal, alternate 4 hours of transverse and 20 hours of longitudinal data taking. Do NMR before and after transverse, and every 5 hours during longitudinal.
- Production at 30 degrees. We may want to start from HMS/SHMS=-2.9/-2.6 momentum setting, complete this and then go back to HMS/SHMS=-3.5/-3.4 momentum.
Hall Access
- The next possible hall access is on Friday, Feb 14th, 2020 when the Wien flip is scheduled by the accelerator.
- Hall C safety walkthrough (5 people)
- Installation of the spare rotation stage. Are the mounting materials ready?
- Power supply swap - replace Agilient with new Kepco.
When there is a down:
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
- Spectrometer GUI (
go_magnets) should always be visible on Shift Leader computer, hcdesk3 - 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.
- If SHMS dipole trips again, take a screenshot of the PSU window before resetting the interlock and post it to hclog.
- Spectrometer GUI (
- Inform the RC of any access that the Target Team requires. The RC will coordinate with RadCon to make everything run smoothly.
- The operators have been somewhat careful with our beam orbit locks. 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[10]
- Temporary Laser instructions can be found here [11]
- Do not change SHMS momentum until we fixed the current lead valve
Planned Accelerator Configuration Changes
- 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
