Aug 27, 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. Consider developing data structures for the peak value (Elton: consult with David)
  2. Provide information to Curtis' document on performance for FCAL (Matt) and BCAL (Elton and Zisis)

References

  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. GlueX Performance document: BCAL & FCAL high-level plots GlueX-doc-2775
  4. Run preparations
    • Solenoid cooldown and ramp up mid August
  5. FCAL Update
  6. BCAL Update
    1. Log Entry 3349631 Muon decays (Elton)
  7. Calorimetry F250 Firmware Discussions
  8. Reconstruction and Simulation
    1. Eta reconstruction (Tegan)
  9. Calibration
    1. Effective Speed of Light and Time offsets GlueX-doc-2796 (George)
    2. Preliminary TDC calibration File:BCAL TDC Preliminary.pdf (Mike)
  10. Any other business

Minutes

Attendees: Elton, Mark, Matt, Adesh (JLab); Will, Curtis, Mike (CMU); George (Athens); Ahmed (Regina)

  1. Announcements
  2. Action Items
    • Addition of peak into data structures will be done by Will in consultation with Mark.
  3. GlueX Performance document: BCAL & FCAL high-level plots GlueX-doc-2775
    • Need to modify BCAL entry to eliminate interpretation that goals have been reached. Will will make plots of eta widths to see if they can/should be added. George will produce a z-resolution plot relative to tracking. Should add time resolution for pid. [Note added: Elton and Curtis have recently updated the document].
  4. Run preparations
    • Solenoid cooldown and ramp up mid August
  5. FCAL Update
    1. Hardware (Adesh)
      • FCAL is up and running except for one base
      • Replaced 15 bases. Two bases had the same ids but fixed
      • Serguei is helping to get the stand-along DAQ up and running, setting pedestal values to 100. Should be ready for LED data when the solenoid starts ramping.
      • Hovanes will modify the EPICS interface to check validity of ADC inquiries, which can now be done with updated firmware.
    2. MC (Adesh and Matt)
      • Simulations have checked the reconstructed pi0 width with varying thresholds and gains, but see no changes in the width. This is puzzling, so Adesh is generating single photons to study the simulated detector resolution.
      • Elton: Asked if Simon's timing selection in the clusterizer had any effect on pi0 reconstruction. See Log Entry 3346861. No changes were seen for run 2931.
  6. BCAL Update
    1. Log Entry 3349631 Muon decays (Elton)
      • Statistics have been collected and investigated using the raw window data.
      • The muon lifetime is clearly seen in the data.
      • The occupancy was plotted for electrons and muons. They display some distinct features, likely due to the geometry of bcal and cosmic rays. The highest statistics are in layer 4 where we hope to improve calibrations
      • The naive energy sum of hits accounts for about half the energy expected from Michel electrons and needs further study.
      • An equivalent amount of mode 7 data has been taken. Will is taking a look at it and will write a plugging to analyze it. Initial looks at this data reproduces Elton's results.
    2. Gain ratios (Mark)
      • Completed a plugin to do determine the gain ratios and attenuation lengths and submitted a pull request.
      • The plugin should be run during the next launch so that run-by-run constants can be determined for the ccdb.
  7. Calorimetry F250 Firmware Discussions
    • We have provided feedback to Sasha for updating his document. Expect an advanced draft later this week for comments early next week before passing it on to the fast electronics group.
  8. Reconstruction and Simulation
    1. Eta reconstruction (Tegan)
  9. Calibration
    1. Effective Speed of Light and Time offsets GlueX-doc-2796 (George)
      • Reviewed draft of document on the portal.
      • The measured veff depends on layer and on run conditions (production B=on and B=off and cosmics)
      • Mark: Is the ADC or TDC time being used: Answer is ADC time
      • The value of veff converges on about 17 cm/ns when a selection of hits using |z_point - z_track| < 20 cm.
      • These values will be loaded into ccdb after one iteration of veff, so the selection cut uses initially determined values of veff
      • Offsets: The tup - tdown offsets appear more consistent between various runs and there is no clear layer dependence. Thus there are more stable.
      • Elton: Suggests that the constants (both veff and offsets) be plotted one run vs another for ease of visualization.
      • George: Continues to search for selection cuts which are less biased than the |z_point - z_track| difference.
      • Elton: Suggests to select higher momentum tracks (less multiple scattering and bending may improve extrapolation). Also select on track chi2 if it is not done already.
      • Mike: Consider fitting over a more limited range in z and investigate how this affects veff.
    2. Preliminary TDC calibration File:BCAL TDC Preliminary.pdf (Mike)
      • Added entries into the ccdb to hold TDC time-walk corrections and offsets.
      • Uses peak value for the time-walk corrections, but access is a kludge. Should add entries into the BCAL classes so that the peak value can be accessed directly.
      • Added entries into the ccdb for the runs that were analyzed.
      • The default code continues to use the ADC time, but the TDC time can be selected using a command-line flag.
  10. Any other business
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