May 21, 2015 Calorimetry

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Video Conferencing Information

Meeting Time: 11 a.m.

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Participant Direct Lines

  • JLab Phone: in CC F326 is 757-269-6460 (usual room)
  • JLab Phone in CC L207 is 757-269-7084
  • 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. Work with Hovanes to activate VME LED pulser setup for FCAL (Elton). Orlando has gotten his crypto card to work and will check into operation of the FCAL pulser.


  1. FCAL HDFCAL log book
  2. BCAL HDBCAL log book
  3. BCAL Action Items and Working Tasks

Tentative Agenda

  1. Announcements
  2. Action Items
  3. FCAL Update
  4. BCAL Update
  5. Summer plans
  6. Reconstruction and Simulation
    1. Wavetrain code vs. single-energy code (Tegan)
    2. IU and CURVATURE Shower Comparison (Tegan)
  7. Calibration
  8. Any other business


Attendees:Elton, Jon, Manuel, Adesh, Will, David (JLab); Christina, George (Athens); Zisis, Tegan, Ahmed (Regina)

  1. Announcements
    • Aram Teymurazyan has been hired into the department at Regina as the Fedoruk Chair in Nuclear Imaging (starting July 1)
  2. Action Items
    • Orlando has straightened out the issues with the cryptocard and will work on the FCAL pulser system
  3. FCAL Update
    1. Hardware (Manuel)
      • Hovanes has updated the EPICs IOCs to turn off bases that read above some max voltage (e.g. 2000 V) after verifying the anomalous reading after a preset delay (about 15 s).
      • (Jon) Working on a more permanent fix to this problem by updating the firmware with better diagnostics.
    2. Calibration (Adesh)
      • Working on pi0 and electron calibrations.
      • Looking for pi0 at lower energy threshold and investigating systematics
      • So far charged track showers are included in the samples. Updating software to veto showers connected to charged trcks
      • Considering Bfield=0 runs, which may be used to add to the number of pi0s
    3. Will: Consider adding skim files together into one (using evio_merge_files) to reduce the total number of jobs that need submission
      • BCAL is also using sqlite files for keeping intermediate values of constants during iterations
    4. Charged particle showers (Elton)
      • Posted some plots on charge track matching to FCAL in Log Entry 3341857.
      • There seems to be a cutoff in the momentum (not FCAL shower energy). In conversations with Simon, it may be that this is due to a tracking inefficiency at low angles, which he will investigate. Adesh: Does not see the same cutoff, but requires hits 20 cm < r < 60 cm, which result in apparent cutoff at higher energy. See Log Entry 3341935.
      • The measured width of the FCAL energy in single counters requiring that the momentum lie between 0.975 < p < 1.025 GeV is about 25-30%. Adesh sees widths of order 12%. Elton will redo plots excluding showers close to the beam hole.
      • Adesh: Investigates energy in a single block for tracks matching showers. They appear very uniform at about 50% of the momentum.
      • The pi0 width is about 11-12% for the spring data. Fall data will be inspected next.
  4. BCAL Update
      • See Log Entry 334096 Problematic FADC channel
      • FADC channel reported at collaboration meeting is not understood. The FADC board was replaced, but the problematic channel (#11) is still exhibiting anomalies. Will continue to investigate.
  5. Summer plans
    • Take cosmic-ray data and look for electrons from muon decays (Michel electrons). Tegan will pick up Will's trail and will move toward this analysis working with Andrei on extracting gain factors.
    • Elton will investigate options for running over the weekend.
  6. Reconstruction and Simulation
    1. Wavetrain code vs. single-energy code (Tegan)
      • Plots have been updated since last week
      • At first glance, the 'single energy' code looks more like the data and compares favorably with the 'wavetrain' analysis
      • David: It would be nice to see how the MC compares with real data.
      • Elton: Need to think about how to do the comparison with data. Pedestals could be compared, but should agree with data since parameters were derived that way BGGEN? Parameters per shower might be the easiest to compare.
      • Once final internal checks are completed, Tegan will check in the code after advance warnings to Mark Ito and Sean.
    2. IU and CURVATURE Shower Comparison (Tegan)
      • New code with "curvature" tables has been implemented and comparisons made with nominal reconstruction. Most variables compare closely.
      • Elton: On the z-distribution, events reporting z positions outside the BCAL are being dropped in the "curvature" reconstruction. Should consider a way of keeping these events, even if they report outside the physical boundaries due to resolution. Tegan and Zisis will consult Andrei on the best way to accomplish this.
  7. Calibration
      • Effective Velocity (George)
      • Plotting zshwr = 0.5 ceff(tu=td) vs ztrak. Slope of linear fit (p1) determines the measured veff relative to the value in the data base ceff=16.75 cm/ns.
      • Discussion of results and systematics seen in first look at data.
      • For next time, analysis will be iterated and should be ready for inclusion into the db.
    1. Update on pi0 reconstruction (Will)
      • See Log Entry 3341906
      • pi0 width and mass plotted vs z of shower. There is some systematics seen in the mass position (increasing with z)
      • Warning: Care needs to be taken with the origin used in BCAL and FCAL z coordinates, some are referenced to the center of the target, not the global coordinate system. David: Should consider changing everything to the global coordinate system to avoid confusion.
      • Will continue to investigate systematics for the mass and width
      • First look at omega -> pi0 gamma
  8. Any other business