RC meeting and Run Plan, Wednesday Nov 21
From HallCWiki
Contents
RC Meeting Information
RC Daily Meetings are at 4:30 PM, 2nd floor Counting House Meeting Room
- 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
Useful Links
- Detailed Kinematic Group Settings
- KaonLT-SIDIS Group 2018-2019 Shift Schedule
- Hall-C Controls
- Hall-C Logbook
- MCC White Board
Current Status
- Since swing yesterday beam was less reliable than weekend, e.g. two separate downtimes >1hr in owl shift (details in RC daily update).
- At ~13:40 today completed kinematic Group 15 (Q2 = 4.77, x = 0.6, pi+)
- Reconfigured and currently running for Group 11 (Q2 = 5, x = 0.5, pi+)
- During HMS spectrometer move, drive controllers flagged red, reset not possible, tech-on-call called and controlled access made by J. Beaufait to reset shunt trip breakers on HMS and SHMS.
- RC Daily Update Wednesday, November 21
Current Run Plan
- Order of Kinematic Groups
- Group 11 (Q2 = 5.0, x = 0.5, pi+)
- For 11-3 rate test setting will be performed (changing beam current and cross-checking good coincidence yields)
- Group 12 (Q2 = 5.0, x = 0.5, pi-)
- Group 8 (Q2 = 3.979, x = 0.5, pi-)
- Group 7 (Q2 = 3.979, x = 0.5, pi+)
- Group 11 (Q2 = 5.0, x = 0.5, pi+)
Notices in Effect for Shift Crew
- If the HV trips for SHMS S1Y5B contact Simona M. DO NOT change the HV from the nominal value!
- Shift leaders, please fill out the check list once per shift!
- It is no longer required to fill out the standard.kinematics file online, it is now done automagically
- Split the large desired charge between multiple runs (~1 hour per run)
- Listed currents are estimates. For runs at less than 60uA, increase current until SHMS singles rates are between 400k-500k.
- How-to power cycle PLC I/O chassis: https://logbooks.jlab.org/entry/3625862, https://logbooks.jlab.org/entry/3625900
Current Issues
- Worsening of coincidence time resolution
- Cause of coin. time jitter (resolution loss) may have been found? -Brad S.
- Coincidence time after insertion of passive delay -Dave G.
- Follow-up Re: Coincidence time after insertion of passive delay -Dave G. with comment from Dave M.
- More jitter tests -- nothing found on scope... -Brad S.
- HMS/SHMS TOF resolutions using hodoscope beta -Mark J.
- RF time and coincidence time -Mark J.
- Yet more jitter tests -- found small issue w/ ref time, but nothing that impacts coin. times -Brad S.
Planned Accesses to the Hall
- Monday Nov 26 energy change and move to restricted access. Current plan according to MCC white board is to lock up Hall Tue swing.
- Monday Nov 26:
- Aerogel change
- Vladimir Berdnikov and Walter Kellner's team
- Need SHMS below 20 deg. and the HMS above 40 deg.
- HallC ramp
- SHMS HB magnet field OFF, detectors HV OFF, roof OFF (craning operation)
- SHMS hut, detector site will be occupied (craning operations)
- 8h for operation minimum
- As less activity in the hall as possible
- HGC work, Walter K. is aware, Brad and others from University of Regina will work around aerogel change.
- Walkthrough request in morning for University of Regina.
- Dave Meekins has requested access to Hall and to the top of the target with manlift to diagnose the issue and possibly affect a repair on the loop 3 JT valve. Need to coordinate with Walter.
- Aerogel change
- Tuesday Nov 27:
- Walter Kellner and Steve Lassiter will install brushes (originally planned for Tuesday and Wednesday, need to coordinate if possible only to be done on Tue)
Planned Accelerator Configuration Changes
- Monday, Nov 26: Energy change to 1.86 GeV/pass, we will be moved over to 500 MHz laser.
- Current plan is swing Tue 11/27 Hall will be locked up (see MCC scheduling board).
- Target group recommend keeping target cold for 4 shifts between Monday Day and Tuesday Swing (Tue D. Meekins removing tritium from Hall A so unavailable to re-condense in C).
- Sunday D. Meekins will warm up the Hall A target (shouldn't be affected)
Special Requests
- Harp scan at 3H07A and 3H07B with raster off to address possible issues with harp (https://logbooks.jlab.org/entry/3624463)