Jan 10, 2019 Calorimeter

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Meeting Time: 11:00 a.m.

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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. FCAL: Cross check MC changes by Richard to make sure that gains are not affected in both Geant3 and Geant4 (Matt/IHEP)
  2. Fix FCAL online monitoring plugin to properly plot low level digi quantities in 2D displays. 2D display of pedestal is hard to get because occupancy plot is filled in a different loop. (Tolga)
  3. BCAL: Check pulsing rate of LED triggers when FP trigger bit is missing (start with early runs in fall 2018). With discerning software, check pulsing rate of later runs where it appeared that the downstream FP LED bit was not firing.

Long term items:

  1. From Mike's work: -cos(phi) type dependence in the data and a phi dependence at the downstream end of the bcal. See Sep 21, 2017 Calorimeter Meeting.
  2. FCAL: It has been noticed that the pi0 mass shifts when the LED pulser runs at high rate. This is still not understood. See Log Entry 3595928 and references.

Goals for Calorimetry Group

  1. Determine preliminary photon reconstruction efficiencies as a function of E, phi and theta in data and simulation with a point-to-point precision of at least 5%.
  2. Measure systematics of pi0/eta mass calibration as a function of detector position to a precision of at east 5 MeV.
  3. Demonstrate agreement of photon reconstruction efficiency and resolution between data and simulation as a function of E, phi and theta to within 5%.


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

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Run Updates
    1. FCAL
    2. BCAL
  4. Calibrations
  5. Reconstruction and Simulation
    1. hdgeant vs hdgeant4 calorimeter response (Richard)
    2. Costhe Efficiency Method (Elton)
  6. Monitoring
  7. Review of Goals for the Calorimetry Group
    • Discussion was postponed to a future meeting.
  8. NIM articles
  9. Any other business


Attending: Elton, Colin, Mark (JLab); Curtis, Will, Alex (CMU); Matt (IU); Christina, George (Athens); Zisis, Tegan, Karthik (Regina); Richard (Counting House); Tolga (FSU).

  1. Announcements
  2. Curtis: Collaboration meeting Feb 22-24. Template is up. There is a section on Detectors.
  3. Action Items
  4. Run Updates
    1. FCAL
      • Turned FCAL back on and only a few bases need replacing.
      • PRIMEX will likely load their own voltages for the run. There is already an file archive of the run voltages set for the fall during commissioning.
    2. BCAL
      • Elton: Pressure in upstream chiller has increased since last fall. Josh Foyles has back-flushed the system and replaced filters. The filters collected iron material, which must be residue from iron valves that have been replaced. The pressure came down from about 60 psi down to 30 psi. Tim would like the pressure to remain below 20 psi. Note that the pressure in the downstream chiller is less than 10 psi. They plan to do another flush with 85 degF water, which might help loosen particulates.
  5. Calibrations
    1. FCAL
      • Spring 2018. 4 ns offsets essentially complete. [There are two runs that need to checked, but they looked fine during the last monitoring launch]. Offsets are relative to a single "reference" run that has some 4 ns offsets itself. How these are treated is under discussion.
      • Fall 2018. Offsets of entire crates and slots seem to be more stable. Should require a smaller calibration effort.
    2. BCAL
      • Fall 2018 low level timing Mark: For timing, monitor v8 indicates some channels had been missed, but they are now corrected. Next level of run dependent time calibrations has been completed.
      • Fall 2018 att, gain ratio, position calibrations Mark: These are in process and should be completed soon.
      • Gains: 2018 completed all checks with existing skimmed files. Elton will verify with Sean that the remaining skims get collected.If skim files for fall are already available checks can start on these data.
      • Input from gain ratio (upstream/downstream) to gains. Mark will check that the gain ratios for 2018 are the latest.
      • Mark: Wanted to check that gain ratios are properly included into the CCDB gain constants. Tegan described the process and it seems correct. He will work with Karthik to make sure he understands the procedure.
      • Karthik is creating new plots requested by Mark and also developing a comprehensive set of plots for a summary report on ains.
  6. Reconstruction and Simulation
    1. hdgeant vs hdgeant4 calorimeter response (Richard)
      • Sean had mentioned that there have been some inconsistencies in shower simulation/reconstruction between hdgeant and hdgeant4.
      • To check this, single showers were generated with hdgeant and hdgeant4 and the measured vs through showers were plotted.
      • Some systematics were found in FCAl and BCAL, but in all cases, the differences between hdgeant and hdgeant4 were smaller than measured systematics.
      • The main systematic in the FCAL was the slope (p1) had some theta dependence.
      • The main systematic in the BCAL was a non-zero offset (~70 MeV) prevalent at lower angles (~20 deg).
      • Mark: Some of these systematics could arise from using profile histograms instead of fitting Gaussians. Richard will redo his plots using Gaussian fits (instead of averages given by the profile plot).
    2. Costhe Efficiency Method (Elton)
  7. Monitoring
  8. Review of Goals for the Calorimetry Group
    • Discussion was postponed to a later meeting.
  9. NIM articles
  10. Any other business