RC Meeting, Monday, Dec 20, 2021

RC Meeting Information

RC Daily Meetings are at 10 AM, 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

Useful Links

• Fall 2021 Shift Schedule
• PionLT Physics Status
• PionLT Runplans
• Hall-C Controls
• Hall-C Logbook
• MCC White Board
• Note: 7:45, 8 am and 1:30 scheduling meetings have switched to Zoom
  • OPS 7:45 RC meeting Zoom link
  • OPS daily 8:00 meeting and Wed 1:30 new Zoom link

Announcements

• There will be a test of the JLab Access Control System Tuesday (Dec. 21) at 8 pm for about 30 minutes. JLab badges will not work to unlock doors during that time, so the Counting House, CEBAF Center, etc. will not be accessible.
• We will switch to Zoom for RC meetings starting in January. I will post updated links on the wiki next year.

Current Status

Current RC: Dave Gaskell

• Taking data on LH2, pi+ Q2 =6.00 GeV2, W=2.40 GeV, x=0.55, low epsilon, left. 5766 good pion events so far.
• Completed aluminum dummy pi+ Q2 =6.00 GeV2, W=2.40 GeV, x=0.55, low epsilon (SHMS left) running at 4:15 pm yesterday (Sunday).
• Beam off since 1 am due to issue with 1L05 RF

Future plans

• BCM calibration - Monday afternoon (2:30 pm): Note this may be cut depending on when beam comes back
• Need about 2 more shifts of high efficiency running to get full statistics on LH2 at this setting
• We will likely not attempt to begin the next setting (Q2=2.45, W=3.2)
• If time remains after completing LH2 at this angle, suggest going back to 9.12 degrees to get more statistics on LH2

Current Run Plan

We are currently on (Ebeam=8.0 GeV) Q2=6.00, W=2.40, x=0.55, low ε data taking – PART TWO [See run plan]

• Target: LH2
• Q2=6.00 GeV2, W=2.40 GeV, x=0.55, low epsilon,
• HMS angle=34.58deg, HMS momentum = -2.139 GeV/c
• SHMS angle= 13.12deg (left), SHMS momentum= 5.512 GeV/c

Notices in Effect for Shift Crew

• The Raster Coil pair Ax and Ay are off. Raster needs to be at 4x4. Raster gui has been updated - can now request 2x2.
• With LHe alarms it is good to check the cameras for plumes. If no plume and it is below the LO alarm and above LOLO then monitor with a plot and halog the problem.
• With LNitrogen alarms are not that critical. Just need to start monitoring the problem with plot and Halog.

Current Issues

• Vertical beam position on target has changed a little - will ask Dave Meekins to adjust target ladder positions when beam returns in January.
• There is a rotation issue that has come up if moving HMS between 19 to 25 degrees. It usually gets stuck around this range, please be wary of this issue. We will likely skip settings in this range if this drive controller error cannot be solved. For singles it will not be a big deal to skip settings for HMS at those angles. We need a longer access to address this issue.
  • SHMS cannot be rotated to angles > 30 degrees - the proximity switch has either moved or was accidentally set in the wrong place. Not an issue for now - will be addressed before we restart in January,
• The Raster Coil pair Ax and Ay are off
• Diffuser limit at 46uA (Note: is this still valid?)

Crew Chiefs, We have permission to raise the Hall C diffuser raster limit to allow running >46uA to Hall C. This limit is normally imposed when one of the two rasters is not operative. Since the hall was able to double the running raster current to get the same size raster on the target as having both rasters, Keith is allowing us to raise the limit. To get to the setting, open the Hall C diffuser interlocks screen. Go to the bottom right corner and open the Expert screen. Just below and to the right of the FSD bits, raise the "Raster 1 OK Limit" to slightly above the highest current the hall wants to run at. Do not change the Raster 2 limit. Make a log entry with screen shots. Make an ABIL entry, System MPS and an expected removal date of 3 Jan. 2022. Paul

Planned Accesses to the Hall

• None

Planned Accelerator Configuration Changes

• None

Special Requests

• Tasks for end of run at 7 am Tuesday
  • Ramp down all SHMS and HMS magnets to zero
  • Turn off detector HV except for the HMS and SHMS scintillators (Simona wants to take some cosmic data)
  • Dave Meekins will warm up the target early Tuesday (target operator does not need to stay around - Dave G. will watch the target if needed)