June 29, 2022
From HallCWiki
Revision as of 09:48, 29 June 2022 by Wmhenry (talk | contribs) (→Notices in Effect for Shift Crew)
Current Status
- Accelerator status:
- RF recovery and access to tunnel made yesterday
- After the down we could only get to 25 uA
- Down for the day as more work is done to get us to higher current (RF restoration, try magnetic extraction, look at 8E02 BLM on scope,......)
- 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 91 of run plan 3 10% of LD2 data collected. Dummy data taken for this setting on OWL. Current Setting: Q2=3.85, W=3.07, x=0.31, high ε data taking.
- Q2 power supply was repaired yesterday
- Drift chamber noise is absent in latest runs
Current Run Plan
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.
- Keep on eye on HMS DC chamber wire maps. See current issues
- Contact Brad S. before next spectrometer rotation unless (OWL shift)
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
- Gains and offset need to be update https://logbooks.jlab.org/entry/4006872
Planned Accesses to the Hall
- Need new plan to address HMS DC noise. Check thresholds on cards, low voltages, check grounding, add copper tape, and follow Brad's suggestions. Last resort we can swap nanometrics card.
- Will notify SoLID parasitic group to see if they need access
Planned Accelerator Configuration Changes
- Possibly take down machine Monday to get us to higher currents
Special Requests
- Install telegram on RC Phone (DONE)