RC meeting and Run Plan, Tuesday Oct. 3, 2023

Return to the RC Meeting Calendar

RC Meeting Information

Time: Monday - Friday at 3:30pm

• Location: Counting house conference room

• ZoomGov Meeting Connection Information

https://sbs.jlab.org/cgi-bin/DocDB/private/ShowDocument?docid=431

Useful Links

• MCC White Board
• CEBAF status
• Accelerator Status

Procedures

Hall A call-in instructions:

• Call RC first.
• Techs on site 7am-4:30pm Mon-Thu, 7-11am Fri. RC will call Hall A work coordinator (Zach) during normal working hours. After hours, RC calls Tech on-call.
• After 9pm everything non-emergency needs to be deferred. What is emergency and what's not? Call RC. RC talks with Mark to decide.

Hall Access procedure:

• Access check list (binder on the counting room desk) needs to be filled out before making an access.
• Scan (take pictures with phone) and post it to the logbook.
• Any work inside the SBS, BB boundary need to have PS locked out -- requires two QEWs to throw the big switch. Exception: field measurements.

New instruction for shift crew when changing target:

• Beam restoration instructions have been updated. Printed version is in the counting room.
• When we change target, make sure the SOFs of Target BPMs are set to the correct values.
• SOFs for different targets: Look in the 'HOW TOs' page on the SBS Wiki for details (Note: SOFs for major target positions are on the Control Room whiteboard.)

Status Update

Overall Summary

After the access was completed yesterday, the beam was not restored until mid-way through SWING shift. Due to fighting with the DAQ, production was not ready to restart until 11:35 pm. During OWL shift, production data was taken at 40uA to let the target polarization continue to recover from the 8 hours that the lasers were off. DAY shift increased the beam current to 45uA, where it has stayed since.

Accelerator status

• The 4-pass separator work took 12 hours to complete, so beam recovery couldn't start until 9:15pm.
• Since then, the beam has been stable at 45uA.
• Hall B plan on restarting during SWING shift, but this isn't set in stone.
• No maintenance day on the MCC white board (until 10/10/2023).

Data collected :

• Accumulated corrected charge collected: 0.972C from midnight until 1:30pm.
  • 0.685C during OWL
  • 0.287C during DAY (until 1:30pm)

Hall A Subsystems Status

Target

• The target span up overnight, and is stable.
• Latest polarization measurement: 38.3% (https://logbooks.jlab.org/entry/4191731).

Hall access requests

• If anyone wants to make an access, let me know! There is no planned maintenance day before Tuesday 10th, so any accesses need to be opportunistic.

Shift schedule

• Still need to fill open slots
  • 10/5 - need a TO for OWL
• Please check when your shifts are!

https://misportal.jlab.org/mis/physics/shiftSchedule/?experimentRunId=SBS-GEn-2022

Please sign up for any open shifts!

Short Term Run plan

• Continue running at 45uA.
  • If the target polarization drops significantly, lower the current to 40uA.

==> List of items in case He3 production running isn’t ready:

1. Take data on reference cell at 10 atm H2 (portions that add up to 1 day) [85% (4200 elastic events) more data required for Bigbite momentum calibration]
2. BigBite Sieve slit => only during day (Techs needed)
   1. with 8 carbon foils and take optics for 1 hr at 40 uA (Sean/Andrew - confirm time)
   2. 1 hour for single foil (magnets off) => Chance BBcal HV setting to appropriate values
3. BigBite/single foil location reconstruction (~20 mins?) - BigBite + HCAL detector experts on call consulting analysis experts like Andrew/Sean (magnet on)