Sep 25, 2014 Calorimetry

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Video Conferencing Information

Meeting Time: 11:30 a.m. Eastern (until switch from DST and then return to 11:00am)

  1. To join via a Web Browser, go to the page [1]
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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. Determine the effect of the mis-placing ch 0-8 of SiPM in downstream modules. (Elton) See meeting notes
  2. Add iron shields to top cosmic-ray counters (Elton)
  3. Investigate difference between north and south trigger rates (Andrei) See meeting notes
  4. Check into procedure for new MOUs (Elton)

Tentative Agenda

  1. Announcements
  2. Time of WG meeting
  3. Collaboration Meeting
  4. Action Items
  5. On call pager
  6. FCAL HDFCAL log book
  7. BCAL HDBCAL log book
  8. Reconstruction and Simulation
  9. Calibration
  10. Any other business


Attendees: Elton, Manuel, Mark, Will, Andrei, Irina (JLab); Zisis, Ahmed Foda, Tegan, Noemi, Laura (UofR); Matt (IU).

  1. Announcements
    • Accelerator schedule nominally to begin operation Oct 3, closeup of Hall D on Oct 10, photon beam commissioning starting Oct 17. See e-mail from Eugene
  2. Action Items
  3. On call cell phone (Elton)
    • On-call cell phone for calorimeters and scintillation counters
    • Will need to cross-train between Bcal and Fcal, but also with other systems, such as TOF and SC
    • Need to develop 'expert' documentation for reference and also to help training
  4. FCAL HDFCAL log book (Manuel)
    1. Slow controls
      • Significant progress on control software and GUIs to control HV
      • Need to update documentation to point to new GUIs
      • Monitoring data from the last week was lost during conversion to EPICS based system
    2. Triggering
      • External triggering electronics is being moved from NIM to VME
      • LED pulser trigger is not outputing NIM signals as it does for the Bcal.
      • Hovanes will update the firmware to the latest version
    3. Base problems (Matt)
      • Problems are being checked by Paul Smith at IU
      • IU needs to develop a more complete test setup to study problems in detail
      • One problem of bases resetting has been traced to a reset pin sensitive due to poor quality control
    4. Anagate quatro (Zisis noted this in the log book)
      • Manuel: Sporadic problem found with the anagate that provides power to 400 bases. This one replaced, but problems also seen with new one. Keeping an eye on this one.
      • Would like to add a remote power reset on this one.
      • (Elton) We are also investigating switched power distribution units (PDUs) that would allow us to remotely reset the Bcal bias crates also.
  5. BCAL HDBCAL log book
    1. Bias settings (Elton)
      • First 8 SiPMs on the downstream readout assemblies are being powered by the wrong HV line, i.e. HV1 feeds SiPMs that should be feed with HV2 and vice-versa. Same is true for HV3,4.
      • Checking the values of the HV1-HV2 and HV3-HV4 show that the difference is usually within 10 mV, sometimes as high as 15 mV on a few channels.
      • The voltage settings at T=18degC are within 20 mV of the voltage settings at T=5 deg C. We may wish to stay with a single voltage settings for all temperatures.
    2. TDCs (Mark)
      • Need a reference time to use the TDCs. For this fall run, we will not have the RF signal available and discussions are ongoing to decide how to address this for this upcoming commissioning run.
      • Log entry showing the resolution for ADCs and TDCs (no time-walk corrections) from LED pulser runs
      • Log entry showing the time-walk of TDCs for various thresholds (250, 100, 50 mV). Because the TDC have an additional factor of x5 gain, this corresponds to ADC pulses of 50, 20 and 10 mV.
    3. Cosmic-ray trigger (Andrei)
      • Andrei investigated the discrepancy between north and south trigger rates
      • First noted that the rates in the bottom counters was about 5 Hz (south) and 10 Hz (north), where the expected rate is about 50 Hz.
      • Raised the HV in the counters about 300 V and adjusted the rates to be about the same.
      • The new rates in the bottom counters are now about 100 Hz (twice expected from cosmics).
      • Rates in cosmic-ray data taken with the new conditions north/south are within a factor of 2. A direct comparison to previous rates was not possible because of pedestals problems on the trigger counters.
      • The remaining asymmetry may be due to the offset of the top trigger counter to the north. Cosmic-ray simulations seem to show this level of effect
  6. Reconstruction and Simulation
    1. (Will) Generating pi0 data with BGGEN to estimate data quantity needed for calibrations
      • Using the commissioning and reconstruction geometry
      • Need more statistics. Waiting on events being generated by Sean and follow up with suggestions from Simon
      • Report at collaboration meeting
    2. Fcal reconstruction studies (Matt)
      • IU has developed a plugin that takes info from Paul's framework and drill down to the block level energies. This might be useful to Will in developing similar code for Bcal. Matt will send Will the plugin file.
      • IU is also looking at inclusive omega->gamma pi0 reactions in order to tag clean pi0 showers. These could be generally useful in calorimeter calibrations.
    3. BDT studies (Tegan)
      • Tegan and Justin presented their latest work at the reconstruction meeting last week.
      • Comparison with Will L.'s cut-based code, shows it worked reasonably well.
      • Update at the collaboration meeting.
      • (Matt) The REST format saves only limited data. There are some parameters, such as E9/E25 shower shape parameters that might be useful in reconstruction and also should be saved. As reconstruction proceeds, we need to think about what additional information should be added to the REST data format.
  7. Calibration
    • Noemi is getting up to speed to the calibration software and should start contribution soon.
  8. Any other business