Jun 4, 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. Keep events reporting z outside the BCAL physical boundaries in the "curvature" reconstruction (Tegan)
  2. Change BCAL and FCAL coordinates use the global coordinate system (not the target center) (who?)
  3. Understand BCAL efficiency estimates (cluster vs enhanced) for m7 and m8 data taking modes (Ahmed)


  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. Summer plans
  4. FCAL Update
  5. BCAL Update
  6. F250 firmware discussion
  7. Reconstruction and Simulation
  8. Calibration
  9. Any other business


Attendees: Elton, Matt, Mark, Adesh, Manuel, Will (JLab); George (Athens); Sean (NW); Noemi, Ahmed, Tegan (UofR).

  1. Announcements
  2. Action Items
  3. Summer plans
  4. FCAL Update
    1. FCAL studies of Pedestal and Pulse Integral (Manuel)
      • See Log Entry 3342815
      • Study of pedestal widths depending on number of samples, either in a single event or over multiple events
      • Consider using a rolling average (using multiple events)
      • Data set from last summer taken at about 100 Hz
      • Finds variation of peak/peak ~ 1.5 %.
      • Sean: Studies of optimal NSA should look at beam data, since pulse shapes may be different between pulser and physics data.
      • Elton: Should look at the pulse height variation of the widths.
    2. Calibration (Adesh)
      • Working on plugins, but debugging in progress
      • Goal is to create pi0 and electron skimmed files with ROOT trees for ease in calibration
    3. Other
      • Jon is working on firmware for bases.
  5. BCAL Update
    1. LED bias scans (Mark)
      • Completed analysis of bias scans.
      • Some interesting results. Results depend (very slightly) on which LED side the pulser is flashing.
      • At the Vover=0 V we still measure a small signal (~5% of nominal) indicating that the break down voltage is not precisely set (to within about 50 mV).
      • Estimating the gain changes between the fall and spring run gives (T=18 deg V=1.2 / T=10 deg V=1.4) ~ 0.73. The ratio of gains determined by Will using pi0s gives a ratio of 0.69. Consistency is within 6%. The remaining difference might be able to be explained by temperature changes of the LED and could be investigated by taking data with opposite sides set a different temperatures. However, in practice we will need to calibrate with data at the settings of the experiment, so detailed understanding of these systematics are probably not necessary.
  6. F250 firmware discussion
    1. GlueX-doc-2752 fADC250 Operational Characterization: Air Flow, Temperature and Pedestals
  7. Reconstruction and Simulation
      • pi0 peak reconstruction (Tegan)
      • Comparison of mcsmear output using original and updated code.
      • Comparison is reasonable, but differences remain.
      • Pi0 peak for both reconstructions is at about 100 MeV. Suggested that variation=mc for ccdb should be used. [Note added: Tegan already made new plots with this setting and indeed peaks went up to about 120 MeV]
      • [Note added] Elton: At this point, the comparison between new/old is not as important as understanding how the generated energies in geant are propagated to simulated hits with new code.
    1. Efficiencies (Ahmed)
      • Trying to investigate differences in efficiencies between mode 7 and mode 8 by targeting events which are not reconstructed
      • Finding some inconsistencies between hdview2 and analysis, which needs further investigation
  8. Calibration
    • BCAL - Effective Velocities and Time Offsets (George)
    • Good progress. Systematic differences between layers is notable, but is smaller for cosmic-rays compared to beam data.
    • Sean: Mike Staib is working on CDC alignment, and may have useful tracking updates
    • Will: Could consider using beam data with B=0 for comparison to cosmic runs
    • Elton: Concern that there is bias when choosing the radius of intersection for track based on the measured value of z in shower.
    • First report on time offsets between upstream and downstream, which are close to zero.
  9. Any other business
    • BCAL - Radial Dimensions (George)
    • Differences found in the geometry between different ways to access them. Elton will check with David L.