May 31, 2018 Calorimeter

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Video Conferencing Information

Meeting Time: 11:00 a.m.

  1. To join via a Web Browser, go to the page [1]
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Participant Direct Lines

  • JLab Phone in CC L207 is 757-269-7084 (usual room)
  • JLab Phone: in CC F326 is 757-269-6460
  • Phone in the Regina Video-conference Suite is 306-585-4204
  • Athens Phone: in Christina's office is 011-30-210-727-6947

Action Items

  1. Add new gain calibrations to ccdb (Tegan) Preliminary constants added about three weeks ago.
  2. Homework from NIM paper. Non-linearity correction of SiPMs (Elton)
  3. Enrich pi0 skim with layer 3 events (Tegan with support from Sean/Mark)
  4. BCAL: Create non-linearity corrections for MC for gain adjustment.
  5. BCAL fixes: Hot TDC channel

Complete after new launch

  1. Report back on study of eta with in FCAL [Mark] Lost track of specific reason for this item. Presumably interest in evaluating FCAL calibration for an independent set of data from the pi0 used to calibrate. Also, the eta mass resolution is only weakly dependent on the position resolution (unlike the pi0). Finally the eta pi+pi- final state can use the vertex obtained from the charged pions to determine the vertex. Pass this check onto the FCAL group.
  2. From Mike's work: -cos(phi) type dependence in the data and a phi dependence at the downstream end of the bcal


  1. FCAL HDFCAL log book
  2. BCAL HDBCAL log book

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Collaboration Meeting Spring 2018
  4. Run Updates
    1. FCAL
    2. BCAL
  5. Calibrations
  6. Monitoring
  7. Reconstruction and Simulation
  8. NIM articles
  9. Any other business


Attending:Elton, Simon, Colin, Mark (JLab); Tegan, Zisis, Ahmed (UofR); Christina (Athens); Sean (FSU); Tolga (FIU); Jon, Jared (IU); Curtis (CMU)

  1. Announcements
    • None
  2. Action Items
    1. Gain update / skims (Tegan)
      • Reduced skims have been created from the original skims to shorten iteration times. But a bug was found and new reduced skims are being produced.
      • Preliminary 2018 gains for the BCAL were entered into ccdb about three weeks ago.
      • Gain matching will be conducted using a tagged version of the code so that changes are confined to differences in the constants.
      • Sean: Suggested that Tegan use the tagged version from the Workfest. This one is stable and will be used as a basis for the next reconstruction launch.
  3. Collaboration Meeting Spring 2018
  4. Run Updates
    1. FCAL (Colin)
      • Turned off FCAL about a week ago after swapping out a final set of bases.
      • Base failure rate during beam ~8-12 bases/week
      • Base failure during downtime ~ 2 bases / week. Last Nov replaced 60-70 bases at turnon after about 25 weeks off.
      • So far about 19 "repaired" have failed and are being evaluated. They are on the test bench and will be checked later today.
      • Curtis: How many failures to date? Colin/Jon: About 500. Suggest that these numbers be collected for the collaboration meeting.
      • Handful of "repaired" bases do not show a signal
      • Plan to turn the FCAL back on at the end of July with sufficient time to check status and replace any failed bases.
      • Curtis: How may spares? Colin: Have 20-30 ready spares; about 20 bases that need checking and about 20 that need repair (i.e. about 60 total ready for August)
      • Zisis: Consider accelerator schedule that includes both fall and spring running.
    2. BCAL
  5. Calibrations
    1. Calibration Dashboard
      • Reviewed calibration dashboard. BCAL Gain entry needs updating and FCAL timing should be ready soon.
    2. FCAL 4ns Timing Calibratons (Jared, IU)
      • Progress on assessing 4 ns offsets. Procedure is iterative, first determining crate-level shifts, then slot offsets and finally channel offsets.
      • Sean/Mark: There are two sets of tables. One for coarse (4 ns) offsets, which can use the LED events, and a fine timing obtained from physics. Mark noted that the coarse timing for BCAL changes run to run but the fine timing does not, so it makes sense to keep the tables separate.
      • Elton: When will you be ready to update the ccdb with the coarse offsets? Jared: Sometime next week. Sean: Good, we can do a monitoring launch when you are ready.
      • Sean: Who did the fine timing adjustment 2017? Colin did and can repeat for 2018.
      • Mark: Small timing variations of the LED pulser across quadrants is due to the four independently pulsed LED plates in front of the FCAL.
  6. Monitoring
  7. Reconstruction and Simulation
    • Tolga: He is working on some neutron reconstruction, but no results yet. Might present something at the next meeting.
  8. NIM articles
  9. Any other business
    • Zisis: Colleen Henschell is working at UofR this summer. She has built the fine-grained BCAL geometry into geant4. Her task will be to analyze cosmic data and use fine-grained MC to check calibrations, focusing on layer 4. She may give an update at the next meeting.