Apr 7, 2016 Calorimeter

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Video Conferencing Information

Meeting Time: 11:00 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. Modify covariance matrix for FCAL and BCAL to correspond to the current resolution of the detectors (Matt).


  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. Run Preparations
    1. FCAL Update
    2. BCAL Update
  4. Reconstruction and Simulation
  5. Calibration
  6. Any other business


Attendees: Elton, Mark, Simon, Adesh, Curtis, Will, Jon, Andrei (JLab); Sean (NW); Ahmed (Regina); Matt (IU).

  1. Announcements
    • Beam expected 'noonish'
  2. Action Items:
  3. Run Preparations
    1. FCAL Update
      1. Base repairs (Jon)
        • Replace 10 bases this week. One more cannot hold HV, one will not connect
        • Test setup at JLab is operational in CC F117.
        • Failures may be accelerated by temperature. Have a setup that allows heating bases to 35 deg C. Three days of operation in these conditions has had no failures
        • Working with Nick and Chris to get setup operational. Beginning to start repairs by replacing must boards, and possibly comm boards.
        • Some bases are starting to have communication errors in detector, which we had not seen before. No errors seen in the test setup
        • Elton: Is the new computer up and running? Not yet, they need to transfer the ownership before software reinstallation
        • Monitoring with EPICs is showing some discrepancies. The set points on the bases are not reinitialized on soft reset. Working with Hovanes to add bits to EPICS archiver to check the set vs read back.
      2. pi0 calibration (Adesh)
        • Iterating on the pi0 calibration, presently on iteration 2. Pi0 peak has moved from 117 MeV up to 130 MeV, and needs more iterations, which are in progress.
        • Matt: Could consider starting the iteration from gain constants that are scaled to the pi0 mass. Adesh: Has tried that in the past with poor success, so continues with systematic iterations.
        • Sean: Notes that modes borrowed from LQCD are being returned, so there is more pressure on the analysis queues.
        • HV on the pmts will be updated when the calibration is complete
    2. BCAL Update
      • Humidity U1
      • The response of 2 humidity sensors seem to be affected by magnetic field changes, leading to apparent erratic behavior.
      • We had noticed this with a sensor six months ago but did not notice the correlation with magnetic field. Need to continue tracking the response and see if alternative sensors might be available for replacement.
      • LED Pulser
      • Orlando has created a script to loop through various configurations during production running 16 configurations=(1 column at a time, upstream or downstream, two LED bias voltages)
      • He is presently working on an interface to EPICs GUIs so that this can be easily used by shift personnel. At the moment use is by an expert. See BCAL Expert Instructions.
  4. Reconstruction and Simulation
    1. BCAL Cluster Update (Will)
      • Note that some runs have no begin run record and new NSB changes are not accessed.
      • Note added from Sean: The list is available at RunPeriod-2016-02_Validation. The problem is due to an intermittent (?) problem with the ER, which is supposedly fixed, but we're keeping an eye out to see if it continues to occur. The data are usable, but require a different calibration.
      • Clusterizer work improved by 1) having different selection of cells in the Ecell/Ecluster vs separation space
      • 2) separate rho*Delta theta and rho*theta*Delta phi selections
      • 3) Allow rearrangement of cells into clusters after first iteration to move cells into "beat cluster"
    2. Matt: Old KLOE code used cylindrical coordinates with delta Z cuts. Moved to spherical coordinates, that are presently being used and improved by Will
      • Checked clusterizer using samples of single photon and pi0 MC samples
      • Visualization of the improvements of the clusterizer use the new improved BCAL event display by Mark
      • Net effect improves number of pi0 reconstructed by a factor of 50%, pi0 mass mean increases by 9 MeV, width increases slightly, but no calibrations have been done yet with new clusterizer.
      • Seed energy used to start clusterizer has been reduced down to 15 MeV, but may need to be reduced even further for proper reconstruction of 50 MeV showers.
      • Going forward: improvements can be made by making the cuts layer and z dependent.
      • Sean: Has the algorithm been checked with charged pions? No. Mark: Brief look, but this is another challenge because charged particles do not point to the target
      • Matt: KLOE code resulted in a huge number of split-offs for hadrons.
      • Simon: When will these changes be merged into the master? Not this week, but likely next after calibrations and more testing.
    3. mcsmear updates - BCAL, FCAL
      • Need to revisit comparisons with MC after the updates to the clusterizer are made.
      • FCAL: need to check that block thresholds and smearing in the MC are correct and match data.
      • Need to keep track of dead channels, especially bases that are being continually replaced. Adesh: Gains are computed on average and less than a dozen channels are not functioning at any one time. Will need to perform a systematic tudy to see what effect a dozen dead bases has on the reconstruction.
      • Mark: Does CCDB have the hooks to take care of dead channels? Sean: Not for the public version, but he has private version that has such capabilities for testing.
  5. Calibration
    • BCAL calibration (Elton for George)
    • New tables for the veff have been added to CCDB, which allow for a quadratic term
    • The fits with a single linear term (layer dependent) with be used to fill the old veff tables, which will be compatible with existing code
    • The fits with a linear and (layer dependent) quadratic terms will be used to fill the new tables.
    • The code that uses these constants will need to be modified to use the new tables. This is in progress.
    • Sean: Need to check implementation in MC for the quadratic term. Mark: The quadratic term is due to the shower widths developing through the module. Therefore, the MC should already contain this effect.
  6. Any other business
    • Ahmed: Is checking the LED test data in preparation to examine and understand the LED data taken during production. Further discussion will continue offline.