Oct 22, 2015 Calorimetry

From GlueXWiki
Revision as of 15:29, 22 October 2015 by Elton (Talk | contribs) (Minutes)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Video Conferencing Information

Meeting Time: 11:15 a.m. (new time!)

  1. To join via a Web Browser, go to the page [1] https://bluejeans.com/907185247.
  2. To join via Polycom room system go to the IP Address: (bjn.vc) and enter the meeting ID: 907185247.
  3. To join via phone, use one of the following numbers and the Conference ID: 907185247.
    • US or Canada: +1 408 740 7256 or
    • US or Canada: +1 888 240 2560
  4. Upon connection all microphones are automatically muted. To unmute your mike on a Polycom or equivalent unit, enter *4. Unmuting on a computer is trivial as there is a microphone button than can be clicked.
  5. More information on connecting to bluejeans is available.

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

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Commissioning
    1. FCAL Update
    2. BCAL Update
  4. Reconstruction and Simulation
    1. eta/pi0 statistics as a function of beam energy
  5. Calibration
    1. Calibration Challenge
  6. Any other business


Attendees: Elton, Mark, Matt, David (JLab); Sean (NW); Will, Mike, Curtis (CMU); George (Athens); Tegan (UofR)

  1. Announcements
    • At the morning run coordinator meeting it was reported that the accelerator south refrigerator has a problem, which they are diagnosing. This will delay beam by at least one week.
  2. Action Items
  3. FCAL Update
    1. Pedestals (Adesh)
      • Study of comparison of analysis using fixed pedestal for a run with using event-by-event pedestals
      • Finds substantial (~5%) events with an event-by-event pedestal reported as zero. This had a large impact on reconstructed quantities, but could be fixed by using a run pedestal if the event-by-event pedestal was reported as zero.
      • Mike: Time of hit has the coarse resolution time (~1-2 samples) when the pedestal is reported as zero. This needs to be considered in reconstruction.
    2. Time calibration (Adesh)
      • Developing code to determine the timing offsets for FCAL
      • HV settings will be updated based on spring analysis. Dan and Manuel are coming up with proposed settings.
    3. Calibration photons
      • Jon Zarling continues to work with MC to find selection criteria for omegas->pi0 gamma, where the bachelor photon can be used for calibration purposes
      • Based on work that Simon showed at the collaboration meeting, using the recoil proton, one can select a nice sample of exclusive omega events. Further tagging of photons from the pi0 can identify the bachelor photon.
    4. Hardware
      • Continue to investigate bases that turn themselves off spontaneously.
      • Failed bases returned to IU for investigation.
      • Paul Smith at IU found that one base with typical symptoms was fixed when a resistor with excess solder underneath was cleaned/replaced. This resistor acts as a switch to turn the multiplier circuit on when two reference voltages are within predetermined ranges. Its behavior before cleaning off the solder was temperature dependent.
      • Other bases with similar problems were cleaned in the same way, but no all have been completely fixed.
      • Adesh has removed 10 additional bases and shipped back to IU for fixing.
      • Initial concern that bases could be damaged due to new but flawed firmware was not born out. Therefore, when Adesh gets back the FCAL will be powered up and kept on for more extensive tests.
    5. Hadron response (Elton)
      • Log Entry 3354252
      • Investigation of hadrons pointing at Fcal shows that there is a response in addition to the minimum ionizing peak which is not quite understood. Various plots were shown
      • In particular, hadrons that match a single fired Fcal block have an energy distribution with a large response at energies below the mip, which is not understood.
      • Matt: Suggested to check response of TOF to the charged tracks.
  4. BCAL Update
    • Bcal has been turned on and will stay on till the run. The chiller settings are 18 deg C with a typical dew point of 5-6 deg C. This is a comfortable margin.
  5. Reconstruction and Simulation
    1. eta/pi0 statistics as a function of beam energy
      • Exclusive pi0s and etas were selected by using the recoil proton.
      • Will produced a table of the number of photons in the pi0 and eta peaks for different energy ranges, separated according to whether they hit the Bcal or Fcal.
      • Matt: The angular distribution seems to have a dip at about 35 deg. Is this due to the material in the FDC frames? Not clear, Will to investigate
      • Sean: Suggest to look up the cross sections for these reactions so the normalization can be determined.
  6. Calibration
    1. Calibration Challenge
      • All detectors should plan on developing plugins that can be used for automatic run-to-tun calibrations during data launches.
      • (Tegan) Searching for eta' sample, but not successful due to limited statistics.
    2. Veff (Georgios)
      • Aside: President of France visiting Greece, so the brouhaha was distracting him from the meeting
      • As suggested by Mike, George is starting to look at the B not zero cosmic-ray runs for comparison with the extracted vet
  7. Any other business
    • Sean: Paul Mattione mentioned that the kinematic fits for neutrals are presently being limited by incorrect (imperfect?) covariance matrices for the Bcal and Fcal. We should look into this.
    • Matt: For the Fcal this should simply be a matter of scaling factors in the error matrix to match the expected resolution.
    • Elton/Mark: The Bcal error matrix could also be scaled, but would also benefit from improving the clusterizer.