[Sbs] [New Logentry] RC Update [10/4/21]

[flay at jlab.org]

Logentry Text:
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The slides I presented at today's RC meeting are posted to the doc-db: https://sbs.jlab.org/cgi-bin/DocDB/private/ShowDocument?docid=119. 

We're in the final days before beam arrives on Wednesday, and there's a lot of activity going on in the hall and remotely in this final stretch.  Details are below (with updates through about 6:30 pm): 

- BB survey:
  - Give Jessie a threshold for pointing: 20 mm pointing to the target

- Analyzer
  - Good shape; efficiency plots on the GUI
  - Question of DAQ/raw data producing mixed endian-ness of data?
    Replay bug was fixed.
  - Last steps: automating software

- DAQ
  - Iterative improvements, testing TI
  - Full DAQ config testing ongoing 
  - Tested spot++ on standalone LHRS DAQ config (HALOG:3917863, plots in 3917832, 3917838, 3917850, 3917851, )

- HCAL
  - Brian: <more> confused with what's happening with the 24 modules (long tails)
    Not in signal path, HV.  Base, tube, module itself? Latest hypothesis:
    pulser shows gain is very high => problem in module? Light collection in
    WLS may be compromised.  Sebastian and Scott are swapping tubes and bases
    to see if the problem moves with the tube/base or stays with the module.
    if it's with the module, can't fix it in-situ.  Maybe re-glue light guide?
    If no improvement, we'll take data this way, and calibrate HV to compensate
    due to low light collection

- Spectrometer Magnets
  - BigBite & Super BigBite: low-power testing over the weekend
  - BigBite: Leaky hoses swapped with new ones over the weekend and pressure tested (30 mins)
    - Leak found today; fixes ongoing.  Pushes survey to Tuesday
  - Super BigBite: Installation of SBS corrector magnet 
  - Full-field testing planned for Wednesday

- GEMs/Tracking
  - Fixed J2 middle, running with HV since then, big accomplishment/effort
    J2 top remains as the problem.  Need detailed plan for making that swap.
  - All other latency changes
  - Argon gas ran out (!) DF & Alexandre changed that out Sunday
    Working on alarms to monitor this better.  We want this on the shift checklist
    Monitoring flow rates, and <not> pressure readbacks.  Running Ar and C02,
    mixing on site, not pre-mixed.
  - Weekly GEM expert schedule.  Advance notice (to RC) switch bottles
  - Is this mixing system the one to be used in the future? This won't sustain the
    SBS GEMs. Follow-up offline (DF, Kondo, Brad, Jack, others)braces & guards on cabling/LCW hoses

- BB CAL
  - PS calib almost done
  - SH calib complete
  - Looking at calibration scripts to have ready for Wed
    - Trig Rate vs threshold
  - Ready by Wednesday

- Beam Line (monitors, vacuum, correctors,...)
  - BCM u_new flatline? Not unexpected (0 V signal => 0 Hz)
  - Dave Mack & Simona Malace re-configured fanout of Dx10 to Moller polarimeter setup

- Target
  - Vacuum pumpdown of all three sections (target chamber + DP station + downstream beamline) underway
  - Plan to cool with He tomorrow if all goes well tonight
  - No need for a shifter until we condense H2/D2.
  - Need access to the hall for condensation on Wed Oct 6.  Can be controlled access, but <uninterupted>

- Radiation Monitoring
  - Ellen Becker is setting up NDX detectors that will be placed in the BB GEM electronics bunker and the SBS bunker; plan to finish tomorrow. 

- Shifts
  - Cancelled through Wed Owl. On pace for starting shifts for Wed day shift


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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/3917941
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