RC meeting and Run Plan, Monday December 13th

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RC Meeting Information

Run Coordinator: Brian Quinn

Location: Counting House Conference Room

Time: 3:15PM

Remote connection link: https://bluejeans.com/256205934

Toll-Free Number (U.S.& Canada): 1-888-240-2560

Bluejeans Meeting ID: 256 205 934


Upcoming Shift Which Needs Filled

One vacant shift remains until the winter break shutdown:

  1. Sat Dec 18th, OWL, TO

Thanks!!! to Thir, Scott, Nathaniel, Maria, Bob, Sean, Albert, and Zeke!!!... and especially Kondo who filled in for Saturday day, at short notice, allowing us to keep running!! ... and to Alexandre for filling two of the final 3 shifts.

Accelerator and Hall Status

  • Optics studies Tuesday now scheduled for 9:00-11:30.
    • Requested controlled access.
    • There may be some delay getting sweep, all halls will probably go to controlled.
      • PD suggests we shut off beam to Hall at or before 8:15, and request change to controlled
      • RadCon asks we be ready to shutdown earlier, if they are available.
    • GEM chamber, J2, may be removed from the Hall during the access
      • May have to store somewhere safe, if radioactive (probably table in EEL 126... checking with David Hamlette.

Special runs done

  • Friday Day: low current (2 uA) test runs on LD2 with GEM HVs decreased by 50 V, 25 V, and 0V, relative to nominal.
  • Friday Swing: SBS-off running 2hr LH2, 3hr LD2 (With SBS-off HV-settings for BBCal)
  • Saturday Day: BBCal cosmics 3.2 M events (run 12744)
  • Saturday Swing: GRINCH-LED-only runs at 100 Hz with varied HV
  • Sunday Day: HCal-LED-only (run 12775)

Unfortunately, the last 3 were made possible by long accelerator-down periods... including one caused by bird-droppings in Richmond!

To be Done During Extended Down Time

(Nothing left, if J2 is removed tomorrow.)

Run Plan

  • Finishing cycle 16
    • Continue following cycle pattern and ticking off runs-completed on paper copy at SL desk

(Reviewing the Run List shows that the check-off list has gotten out of phase with the numbering of the cycles. Rather than re-numbering the cycles we've been taking, I annotated the Run List with 'long cycles' (20 M LH2, 80 M LD2) starting with Cycle -3! That's followed by cycles -2, -1, 0 and 1. Using that numbering system, we are now on Cycle 16. There were also 7 'short' cycles (10 M LH2, 40 M LD2). )

Opportunistic Access Requests for Tuesday

  • Put network-readable 'scope on trigger signals to quickly identify 70 ns timing shifts. (Alexandre)
  • Try changing HV channel for J0 lower module (to see whether lower current is a result of bad read-back) and perhaps check HV divider (if accessible) (Zeke or Holly).
  • Remove unused HV card from HV mainframe for hodoscope (Ralph)
  • GRINCH (change pulser brightness) (Todd/Maria)
  • Maybe, change rpi & SD card in HCal's upper HV mainframe... Probably NOT!! (Sebastian & Ellen)
  • Test HCal pulser and make measurements with difference latency (Scott & Sebastian)
  • Reboot rpi's for HV mainframes that have been giving trouble (Sebastian)
  • Replace Vetroc in slot 6 (Bryan/Alexandre)

Resolved Issues

  • Low DAQ rate alarm for hung MPD (End, Reset(twice?), configure, download)
  • GRINCH LED pulser now prescaled (PS5=4) to give ~10 Hz
  • "MPD NotFound" error:
    • See two-page printout from GEM documentation, on SL desk
    • On page 3, section 3.3 (marked by bracket in the margin) tells how to boot the VTP crate
    • If that doesn't fix it, see the next page for how to boot UVa MPD crate (or call Alexandre or GEM expert on call)

Unresolved Issues

  • Hodoscope HV alarms (Ralph and Steve are working on it)
  • BBCal HV alarms with CH HV-control showing HV off by more than 50 V while JavaGUI shows it at setpoint
  • BBCal HV alarm with JavaGui showing HV at ~500 V
  • HCal HV changes (contact Scott or Sebastian to reload the values and make sure everything get's properly loaded)
  • Occasional timing shifts of ~70 ns
  • GRINCH sync errors (can be ignored)


Subsystem Updates

  1. HCal
    1. F1 errors (HCal sync errors)... Don't ignore!! End, Reset(twice?), Configure, Download. If that doesn't work, call Alexandre. One happened this morning.
    2. Correlation plot of HCal ADC time and HCal TDC gives clear sign of 70 ns shift in either ADC or TDC... Andrew will add this to the critical plots.
    3. Binder of good and bad HCal plots for LH2 and LD2 target will be put in CH... Sebatian now has the binder.
    4. Sebastian is working on list of runs with timing shifts. Bryan thinks there were only 2 real ones many of remainder caused by SL seeing timing peak of LEDs when beam is off.
  2. BBCal
    1. Many HV communiction issues. Arun wants to reboot rpi tomorrow
    2. Andrew is worried that BBCal rate does not scale linearly with beam current. Seems to go UP more than proportionally with current for change from 1 uA to 12 uA... may be result of measurement errors at low beam current.
  3. Timing Hodoscope
    1. David Hamilton reports Rachel is making progress since discovering left TDC copy of RF signal had a problem. She will report on status in an RC meeting in the near future.
  4. GRINCH
    1. Maria is changing HV to gain-match the tubes. Will be using the DAQ tomorrow during access... talk to her if you need to use it.
  5. GEMS
    1. There are no plans to take out all GEMs over Dec.-Jan. break. Some electronics will be disconnected to allow GEMs to be slid to side for access. Support for J0 4-slot backplane will be repaced with 3-slot backplane.
    2. Diagnosing efficiency would be easier with low current runs (~1-2 uA) on either LH2 or LD2 with low BBcal threshold to give ~3 kHz trigger rate. Done Friday, not yet analyzed.
    3. Andrew believes it is worthwhile to turn on J0 top. Zeke agrees and has tried. A low-voltage problem was encountered, which will be addressed tomorrow by cycling the power and connecting to remote power strip.
    4. May be necessary to by-pass zapped APV card to initilize top module of J0.
    5. J0 bottom may have only a problem with current read-back on HV power supply channel, or problem with HV divider... which may not be possible to address during tomorrow's access.
  6. Beamline
  7. Replay analysis
    1. Will look for LH2 elastic events to use them to understand BBCal and HCal responses.
    2. Trying to calibrate momentum, using H-elastic at lower Q^2.
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