June 24, 2022

Current Status

• Accelerator status:
  • No Beam last 24 hours, expected back any minute
  • RF recovery did not go as well as planned
  • Will try to push to 80 uA (current 45 uA is highest stable available current)
• Experiment status:
  • pionLT continues to make progress on run plan, though we are still behind schedule, unless Ops is able to deliver 80 uA at >50% efficiency
  • On page 33 of run plan. New Setting: Q2=2.45, W=3.20, x=0.21, high ε data taking. Angles are set, awaiting SHMS Dipole troubleshooting

Current Run Plan

pionLT Summer 2022 Run Plan

Physics Status

Notices in Effect for Shift Crew

• Please pro-rate ABU for max current limit in run plan (uA) in beam time accounting. For example, if we receive 15 uA instead of the max_current_limit in the run plan, then the ABU should be: ABU_prorated = 15/(max current limit) * ABU
• Check the HMS/SHMS rates for when production starts, since for Heep coin. production SHMS saw higher rates. Make sure shift crew takes snapshot of scalers at every setting
• When analyzing LD2 or Al dummy or LH2, please leave the target_mass_amu in the standard.kinematics as that of the proton, but when analyzing the data with the pionLT script, specify the target used, as different targets will have different ranges in the cuts when integrating the missing mass peak. Refer to log entry: https://logbooks.jlab.org/entry/4005387 These instructions are given in the pionLT run plan.

Current Issues

• shift crew continues to see HMS DC noise outbursts more frequently, see log-entries:
  • See log-entries: https://logbooks.jlab.org/entry/4005325 , https://logbooks.jlab.org/entry/4005330
  • study noise dependence on HMS DC thresholds, and found that noise temporarily went away @ DC threshold 5.8 V, but re-appeared on the next runs see log-entry --> https://logbooks.jlab.org/entry/4005624 This issue will have to be addressed today during maintenance day
• Hall C BCMs and Accelerator BCMc (i.e., MPS BCMs) mismatch --> https://logbooks.jlab.org/entry/4005801
  • I would think this is just a scale factor missing between the two measurements? Usually S. Wood did this in the past. I have notified S. Wood in the log-entry

Planned Accesses to the Hall

• • Need new plan to address HMS DC noise. Replace cards with spares?

Special Requests

• Mark Jones would like to take HMS optics data with a 4x4 mm^2 raster at some point (when HMS is at a lower momentum, i.e., current setting) for checks. ( DONE )
  • D. Gaskell took a run with Carbon target and raster set to 4x4 mm^2. See run https://logbooks.jlab.org/entry/4004280