RC Meeting, Monday, Dec 13, 2021

RC Meeting Information

   Have RC meeting today

RC Daily Meetings are at 10 AM, remote

• Bluejeans remote connection information:

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 To join via Room System:
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 Meeting ID : 861439920
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Useful Links

• Fall 2021 Shift Schedule
• PionLT Physics Status
• PionLT Runplans
• Hall-C Controls
• Hall-C Logbook
• MCC White Board
• OPS 7:45 RC meeting bluejeans link, weekends usually 9am.
• OPS daily 8:00 meeting and Wed 1:30 bluejeans link

Current Status

RC meeting today

Current RC: Salina Ali, Dave Gaskell takes over after RC meeting

• Owl shift

Continuing from swing shift taking production data on LD2 at 70 uA 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= 9.12deg, SHMS momentum= 5.512 GeV/c; Approx 4500 pions after owl shift

• Day shift

Continue taking production data on LD2 at present settings.

Future plans

• Continue production data at 70 uA for LD2, and switch to LH2 target (estimated toward end of swing shift)
• Photo cathode forecast
• Tues Dec 14th, there is is OPS test plan for 9-1 and Hall access
  • Radcon (David Hamlette) confirmed they can allow controlled access 9-1 pm tomorrow during beam injector test to allow maintenance work on SHMS and HMS. Work by Walter Kellner and Steve Lassiter to start around 10 AM (after radon survey is complete). Not enough time to address HMS rotation issues.

• Check with Steve about moving to 6.16 degrees on Dec 20th. This can be done with remote oversight.
  • Need to be sure that the Gui angle is modified to agree with the true angle when at 8.16 deg.

Current Run Plan

We are currently on 8.0 GeV Part 2 [See run plan]

• Target: LD2

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= 9.12deg, SHMS momentum= 5.512 GeV/c

At about 9:30 am we had about 6500 pions

Notices in Effect for Shift Crew

• The Raster Coil pair Ax and Ay are off. Raster needs to be at 4x4.
• 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

• William Gunning has fixed the issue with the raster pattern showing a rotating rectangle.
• 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 (cannot be done on tuesday 12/14)
  • There is also a rotation issue that comes up with the SHMS but it is more of a forward proximity error and NOT a drive controller error see log entry here.
• UPDATE on target pressure issue: Target pressure issue has been fixed
  • Old: target pressure for loop 2, LH2, is lower than usual - around 17-18 psi. The alarm went off early in the day shift which brought it to the target operator's attention (Bill Henry). Usually acceptable pressure is around 22 psi. If this drops to atmospheric pressure, 14.7 psi, then we have a problem. The pressure for LH2 was around this range 17-18 psi during LD2 runs as well. We did contact target expert JP to resolve issue but it is currently ongoing and UNRESOLVED. We assume we can continue to take data. Most likely this would involve an access to the hall. See log entry from Greg Smith for an update on this issue (12:15 PM 12/11/21)
• The Raster Coil pair Ax and Ay are off
• Diffuser limit at 46uA

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

• OPS Beam injector test tomorrow Tuesday (12/14) scheduled 9 AM- 1 PM (no beam during this time)
  • Radcon (David Hamlette) confirmed they can allow controlled access 9-1 pm tomorrow during beam injector test to allow maintenance work on SHMS and HMS. Work by Walter Kellner and Steve Lassiter to start around 10 AM (after radon survey is complete). Work should take about 2-3 hours. Not long enough of an access to address HMS rotation issues.
    • Maintenance to pump down HMS transfer line.
    • Need to clean the SHMS encoder wheel.

Planned Accelerator Configuration Changes

• none

Special Requests

• none