RC meeting and Run Plan, Tuesday November 23th

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Daily_Meetings

RC Meeting Information

RC Daily Meetings are at 3:15pm, remote connection link: https://bluejeans.com/256205934

Current RC: Brad Sawatzky

Accelerator and Hall Status

  • Hall A is in Restricted Access and the configuration change to SBS-11 is underway -- will be completed at end of DAY shift today
  • Hall will lock-up around 4--5pm today (Tuesday) and Accelerator will proceed with pass change to 5-pass during Swing today (instead of Wed)
    • Please ensure all systems are ready for Production
  • 4th pass separator repairs are ongoing
    • PD Update: 4th Pass IOT
    • This primarily impacts Hall C at this point, but there will be downtimes associated with reintegration and tuning once repairs are completed.


Run Plan for When Beam Returns (Tuesday Evening or Wednesday)

This runplan is a draft.  Stay tuned for changes (and updates to the ??? below.)

Need to assign on-call experts for beam checkout and GEM HV scan portions.
  • Take BBCal cosmics data with magnets on to get HV settings established as soon as Hall can be locked up
    • Keep beam out of the Hall until this is completed
  • Beam restoration to the Hall
    • Start with Sieve IN
    • Ensure target is OUT
    • GEM HVs OFF
    • SBS, BB OFF
    • All other systems should be ready to go
  • After initial steer-up into Hall is complete
    • Verify beam profile with Harp scans
    • Determine raster size and position on target
    • Ramp BB and SBS to production currents
    • Verify beam position and raster size are still good and tweak as necessary.
  • Initial threshold settings for BBCAL and HCAL
    • [FIXME] BBCAL threshold 0.5 GeV (Ensure readback is: 1.00 V)
    • [FIXME] HCAL threshold ??? (??? mV)
  • Turn GEM HV back ON; Ensure other detectors are ready to go.
  • Contact GEM expert to monitor the GEM checkout program [GEM expert on whiteboard]
  • Optics Runs for SBS-11
    • Zero Field Alignment
    • SBS OFF, BB OFF, Sieve IN
    • single C foil target
    • [FIXME] BBCAL threshold 0.5 GeV (??? mV); adjust threshold/beam to get a few kHz of rate
    • I = 5 uA
    • 30 min of beam on target
    • Vertex and Angle Reconstruction 1/2
    • SBS ON (2100A pos.), BB ON (750A neg.), Sieve IN
    • 5-foil Optics target
    • [FIXME] BBCAL threshold 0.8 GeV (??? mV)
    • I = 20 uA
    • 60 min of beam on target
    • Vertex and Angle Reconstruction 2/2
    • SBS ON (2100A pos.), BB ON (750A neg.), Sieve IN
    • 4-foil Optics target
    • [FIXME] BBCAL threshold 0.8 GeV (??? mV)
    • I = 20 uA
    • 60 min of beam on target
  • Escorted Access to take Sieve OUT (needs trained personnel!)
    • Call RC ~1 hour before you will need to do this
  • Low current GEM runs
    • SBS ON (2100A pos.), BB ON (750A neg.)
    • [FIXME] BBCAL threshold 2.0 GeV (??? mV); Can lower threshold to get to a few kHz of triggers
    • 1 uA on LH2 target
    • Take ____ ~5 min long runs with different GEM HV settings for quick voltage scan
      • [FIXME] GEM expert driven
      • Voltages:
  • GEM Rate Study
    • Ensure GEM HVs are back at standard settings
    • SBS ON (2100A pos.), BB ON (750A neg.)
    • [FIXME] BBCAL threshold 2.0 GeV (??? mV) -- want a nominal 100k triggers/run
    • LH2 target
    • I=1 uA ; take 1 30min run
    • I=15 uA ; take 1 30min run
    • I=5 uA ; take 1 30min run
    • I=1 uA ; take 1 30min run
  • Move to Production Running cycle
    • SBS ON (2100A pos.), BB ON (750A neg.)
    • [FIXME] BBCAL threshold 2.0 GeV (??? mV)
    • [FIXME] HCAL threshold ??? (??? mV)
    • Goal: HCAL calib
      • LH2 Target; I = 15uA
      • 10M triggers (nom. 1 hr)
    • Goal: Production
      • LD2 Target; I = 8uA
      • 40M triggers (nom. 4 hr)
    • Goal: HCAL calib
      • LH2 Target; I = 15uA
      • 10M triggers (nom. 1 hr)
    • Goal: Production
      • LD2 Target; I = 8uA
      • 30M triggers (nom. 3 hr)
    • Goal: Production/Dummy
      • Dummy Target; I = 15uA
      • 2.5M triggers (nom. 0.5 hr)
  • This nominally takes us to Friday 11/26 in the SBS-11 Runplan (PDF) document. Progress will be reassessed and subsequent runplan updated as needed.

Reminders / Notes

  • Role sharing between SL and TO was discussed
    • TO should support the SL wherever possible while still keeping primary focus on the target
      • Beam Time accounting; Shift Checklist tasks are low-hanging fruit
      • Suggestion is to have TO start/stop runs and maintain the Run Log spreadsheet?
  • Run plan communication / documentation will be 'officially' documented on the Daily_Meetings#RC_Meetings page
    • Don has made the Run Coordinator 'Run Plan / Report' page more visible on the wiki (and nicely formatted it)

Subsystem Updates

Notes remain from yesterday.  Updates in progress.
  • HV Questions/Issues
    • BB hodoscope readbacks in 'main' GUI broken? [1]
    • HCAL HV status display glitch? [2]
  • HCal:
    • Present data on HCal detector calibrations (timing, energy calibration and uniformity over acceptance, coordinate resolution)
    • Working on clustering in SBS offline
    • Will be using old HVs for SBS-11 startup
  • BBCal:
    • New HV settings made for upcoming BB/SBS on/off settings
      • Contact BBCal experts [Arun] to load these and monitor BBCal performance during beam restart
    • Reminder to group to watch for fringe field impacts on PMT gains in this setting
      • Analysis will be done after lockup later today (hopefully)
    • Parts arrived for PMT dry-air flushing system; needs SSG support
  • Timing hodoscope:
    • working on RF alignment (needs update)
      • Bob M. is concerned about RF signals/hardware
    • HV instructions for hodoscope are in the wiki (and also re-posted to halog)
  • Grinch:
    • Study of LED data taken under different BB+SBS conditions underway
    • Maria/Todd/Bradley will be taking some more opportunistic LED pulser data tonight (Monday)
    • Status update to Halog was requested
  • GEMS:
    • GEM experts will be monitoring the gas bottles over the holidays (should be fine, but extra eyes will help)
    • GEM HV Cosmic Scan Status
      • No analysis of these runs yet -- many had bad latency; may not be useful
    • Work continues on calibrating/understanding the new GEM layer
      • Andrew reports things seem to be generally working, but some issues still being worked on
      • Identified an incorrect guess/assumption for the z-location. When corrected, that significantly improved tracking performance (the steep incident angle for cosmics makes tracking particularly sensitive to the z-location of the layers)
      • Still investigating the following: large number of fake tracks; possible issues with pedestal suppression, or perhaps indication of cross-talk; unclear... (this hypothesis is still under test)
    • GEM "HV-off" cosmics data are on disk -- not clear if it has been looked at (may help disentangle potential cross talk sources)
    • Some confusion over an apparent latency shift for the new UV layer?
      • Identified 2 peaks in a trigger timing histogram separated by ~100ns (4 GEM samples); also seen with EDTM triggers
      • Alex, Mark, Andrew will make a post; one hypthesis is that the TS is doing something strange when two triggers are present at the TS at the same time?
      • Tentative plan is to unplug the BBCal_Lo trigger for now
      • Alex, Andrew, and other DAQ/GEM experts will try to nail down the timing and cause of this shift
  • Beamline:
    • Clock signal rates measured here: https://logbooks.jlab.org/entry/3946822 [Resolved]
    • L-HRS scaler gate fixes and notes: [3], [4] (Bob. M)
      • Notes that the ET events have not been checked recently
    • David F is looking at scaler sanity checks with Paul
  • DAQ:
    • Need electronics diagram that represents 'as-built' system
    • CODA ET library updated Monday afternoon
      • ET system seems to have stabilized. End-of-run scaler event for sbsvme29 reenabled [5]
      • Alex will do some stress tests on DAQ while the Hall is open
    • General DAQ stability?
      • Frequent crashes at start or end of run
      • New runs frequently do not start successfully and require cycles of reset/config/reset
      • Could be ET issue, but some failures tied to VTP crate as well
  • Replay analysis:
    • GEM work is ongoing (see above)
    • Eric working on end-of-run report file output along with Dave F.
    • Updates to BCM Scaler Database Files (David F.)
      • Fixes some duplicate variable names in the TSsbs tree


  • Counting House Computer requests [Ole will be looking into a number of these items]
    • analyzer updated on hadesk machines
    • Streamline access to common tools (halog, go_* scripts, etc)
      • Perhaps get them in a common bin/ directory and added to $PATH?
    • Firefox configurations differ quite a bit depending on user@host
      • Update common configuration to improve useful bookmark toolbar links
      • halog, elog, SBS wiki, Shift crew help, etc
      • 'New' tabs default to something useful, etc
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