RC meeting and Run Plan, Wednesday November 24th

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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 Upcoming RC: Xinzhan Bai (Starting this afternoon) 

Note: Updates in progress below

Accelerator and Hall Status

  • Configuration change to SBS-11 completed during Tuesday DAY shift
  • Accelerator worked on the pass change through Swing into Owl, got some beam into the Hall mid-Owl shift
    • Had difficulties completing the Raster and Beam position checkout. Possibly due to optics issues downstream of the raster in the A-line [1], [2]. Under investigation during day shift
  • DAQ latencies noted on the GEMs seem to be global and caused issues with data taking throughout the night
    • It is still unclear why these changed [3], [4], but latencies are being adjusted based on what we are seeing this morning:
  • Had some trouble with BBhodo HVs [5]
  • Cryo flow to target was found to be constrained last night (This did not impact the program and has been corrected this morning.)
  • Ran into a few computer related issues during Tuesday swing, now corrected [6], [7]
  • 4th pass separator issue will be worked on today (Wednesday)
    • Original 4th Pass IOT ("IOT3") has been declared unrepairable (for now)
    • Plan is to move 2nd Pass IOT up to 4th (then move it back later in the program) [8]
    • 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 Wednesday

This will be updated as we better understand what needs to be redone with corrected readout latencies.
We should be able to complete the 'Initial Beam steer-up', raster and beam position checkout this morning.
  • 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 (MCC driven program to get beam to the dump)
    • Start with Sieve IN
    • Ensure target is OUT
    • GEM HVs OFF
    • SBS, BB Magnets OFF
    • All other systems should be ready to go
  • After initial steer-up into Hall is complete (call Don Jones if you have issues during Swing/Owl or David Flay during the Day Phone Numbers)
    • Verify beam profile with Harp scans
    • Determine raster size and position on target
      • When complete be sure to make a halog and update the whiteboard
    • Ramp BB (750A neg)
    • Call MCC and have them go through their procedure to ramp SBS to production currents (2100A pos) and adjust correctors as needed
    • Verify beam position and raster size are still good. Tweak as necessary.
  • MCC will need to complete Ion Chamber calibrations in this period.
    • 'Thin' target ion chamber calibration may have been completed Wed OWL (covers carbon foils, dummy)
    • Still need to do ion chamber calibration on LD2 target after we are happy with the beam position and raster
  • Initial threshold settings for BBCAL and HCAL
    • BBCAL threshold ~0.5 GeV (readback is: -100 mV)
    • HCAL threshold ~0.5 GeV (readback: -80 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
    • BBCAL threshold 0.5 GeV (-100 mV); adjust threshold/beam to get a ~3 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
    • BBCAL threshold 0.8 GeV (-160 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
    • BBCAL threshold 0.8 GeV (-160 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.)
    • BBCAL threshold set to establish sufficient rate for a GEM efficiency HV scan; Adjust threshold to get to a few kHz of triggers
    • 1 uA on LH2 target
    • Take 7 ~5 min long runs with different GEM HV settings for quick voltage scan
      • GEM expert driven ONLY (ensure GEM expert on shift; or call RC if not sure)
      • Voltages: 3653, 3608, 3564, 3519, 3475, 3430, 3385
Confirm Production Threshold Settings in BBCal and HCal
  • GEM Rate Study
    • Ensure GEM HVs are back at standard settings; detectors should be at Production settings
    • SBS ON (2100A pos.), BB ON (750A neg.)
    • BBCAL threshold 2.0 GeV (-400 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.)
    • BBCAL threshold 2.0 GeV (-400 mV)
    • HCAL threshold ~0.5 GeV (-80 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.
  • Hall A left side camera not responding (can't switch to it) [9]
  • HV Questions/Issues
    • BB hodoscope HV issues [10] (Steve, Ralph?)
    • HCAL HV status display glitch? [11] -- Cause understood. Due to 'Crate OFF' button being used. Largely cosmetic
  • HCal:
    • Present data on HCal detector calibrations (timing, energy calibration and uniformity over acceptance, coordinate resolution) at upcoming meeting
    • 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
    • Parts arrived for PMT dry-air flushing system; needs SSG support
  • Timing hodoscope:
    • Working on RF alignment (needs status update from group)
      • Bob M. has some concerned about RF signals/hardware, group should follow-up with him if analysis/alignment is having problems
  • 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 on LED data 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, mark, Andrew, and other DAQ/GEM experts will try to nail down the timing and cause of this shift
        • Mark will halog a summary of what is now understood
    • DAQ latencies issues noted in the GEMs seem to be global and caused issues with data taking throughout the night
      • It is still unclear why these changed [12], [13], but latencies are being adjusted based on what we are seeing this morning: HCAL, GEM, UV GEMs, BBCAL?, BBHod?, BBGrinch?
  • Beamline:
    • David F is looking at scaler sanity checks with Paul
  • DAQ:
    • Need electronics, timing diagrams that represents 'as-built' system
    • Latency configurations seem to be a mess based on comments in Slack (scattered across many files, interactions between global and 'local' settings, etc)
      • At minimum, this should probably be documented on the wiki?
  • Replay analysis:
    • GEM work is ongoing (see above)
    • Eric working on end-of-run report file output along with Dave F.
      • Probably most useful for full replays? (Online histo display should cover most/all of what the shift crew need to monitor already?)
    • Online analysis golden runs -- what do shift crew check run-by-run
      • Generate a stripped-down set of plots for shift crew monitoring; experts can use a different Panguin config with a full set of plots
    • Plan for full analyses on Farm?
      • This seems to be one of the items holding up more complete analyses of prior data
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