[Sbs] [New Logentry] RC Update [10/6/21]

[flay at jlab.org]

Logentry Text:
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The RC update from the RC meeting is here: https://sbs.jlab.org/cgi-bin/DocDB/public/ShowDocument?docid=122

Overview
- Hall is in Restricted Access
- Jessie and his team have cleaned up the hall
- Jack and his team are powering and testing the magnets to full current on 
  SBS and BB 
- The target group is working on condensing the target; they had software 
  issues during the day, but as of about 5 pm those have been resolved.  
  They will work on condensation, and expect to need a TO at roughly **12 noon Thu**.
- Shift Leader shifts are **cancelled* through Thursday Day.  We have TO shifters on call. 

All teams are working hard in the final stretch; the magnets testing is the 
critical path to obtain the run certificate.  Other notes from today's 
RC meeting are below: 

Magnet Current Settings 
- SBS: 2100 A 
- BB: 750 A   

Analyzer
- Effectively ready for initial commissioning program 
- Progress in setting up automated shift worker analysis 
- Plans: Shift workers type gosbs and run a wrapper/shell script that takes 1--2 command line arguments 
  run-no no-events => replay => bring up analysis GUIs and click through pages of GUI (successively)  
- Division of responsibilities: Shift crew vs experts 
  - Need online GUI parameters (only GEMs have it so far).   
- Training session for shifters, RCs? 
  - Coming in a few days (?)  
- How-To documentation for online analysis is being developed 

DAQ
- Running combined DAQ (GMn1 config) last night.  
- Yesterday: VETROC warnings for the GRINCH (F1TDC).  Bad events? (CODA 3 unidentified event warning in replays 
  seen by DF, Scott B, others)
- Raster test (see beam below) 
- BB shower window reduced by factor of 2 (200 ns -> 100 ns)  
- DAQ running at 4 kHz (good!) 
- sbsvme29 event-by-event readout work ongoing
- Are we turning on the GEM HV tonight (late) or not?
  - Coordinate with Jack since he's doing magnet tests
- All-detector config runs tonight    
  - Make a Pedestal CODA config 

GEMs
- Efficiency: Hypothesis is that it's the new gas mixture system, but not quite sure yet.  
  Minor issues with *configuration* of the DAQ. 
- Seeing efficiencies that make sense 80--90%) with HV before 9/27.  Thereafter down to 60% or so.  
  - Switched from standalone mixed gas system to Hall system that mixes Ar and CO2.  
  - Sean, Zeke, Holly set up pre-mixed gas on J0 earlier today (one of layers that had a huge decrease in eff).  
    Data on this can verify if the Hall gas system is the problem. 
- UVa at lower HV => lower efficiency? 
- INFN showing significantly lower efficiencies; focus gas studies on INFN GEMs? However, gas is the same for 
  the whole system... 
- Compare data from tonight against two nights ago which was a good benchmark.
- Run at HV where we expect high efficiency should tell us something.   

HCAL 
- Gains are pretty well matched at this point 
- Sebastian working on energy calibration code
- EDTM work with Mark Jones; EDTM (HCAL) to EDTM pulser in BB Hodo crate; pulsing fine; coincidence test 
  after this meeting 
- Working on documentation for the first few days (threshold scan + energy calibration) 
- Update DAC GUI 
- Just about ready for beam  

BB CAL 
- Working on documentation (first few minutes, hours, etc).  Thinking about next steps: setting thresholds, etc. 
- SH and PS are calibrated, plots look good 

BB GRINCH
- HV is right where we want it for beam; dialing down from nominal settings; originally matched by gain top to bottom 
  - Multiplicities are single-electron hits with the pulser; trying to be safe for beam.  
- Trying to optimize voltages to get raw PMT counts to about 50% of triggers 
- VETROC scalers stopped working; using up too much CPU cycles? 
- FADC scalers added by the DAQ group
- Documentation is being written; will be updated  
- Tying up last ends; online analysis plots being developed/passed to analysis group   

Beam
- Raster test last night (nominal 2x2).  Found *our* signals are plugged in backwards 
  on FADC (LHRS). Raster pattern looks reasonable
- Need to push replay code to SBS-replay  

Helicity Flip Rate and Reporting
- Settled on **120 Hz prompt reporting**


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This is a plain text email for clients that cannot display HTML.  The full logentry can be found online at https://logbooks.jlab.org/entry/3919256
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