May 22, 2014 Calorimetry

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Teleconference Time: 11:00 a.m. EST

  • ESNET (Number is 8542553) and SeeVogh session (GlueX Calorimetry meeting room)
  • Phone connection only upon request.
    • +1-866-740-1260 : US+Canada
    • +1-303-248-0285 : International
    • then enter participant code: 3421244# (remember the "#").
    • or (and code without the #)

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 Videoconference Suite is 306-585-4204
  • Athens Phone: in Christina's office is 011-30-210-727-6947

Items for followup from previous meeting(s)

Tentative Agenda

  1. Announcements
  2. Action Items
  3. FCAL
  4. BCAL
  5. Reconstruction and Simulation
  6. TDR update
  7. Calibration
  8. Any other business


Attendees: Matt (IU); Pavlos, George (Athens); Zisis, Teigan and Andrei (UofR); Manuel, John, Elton, Will, Shayne, Zach, Jon, Laura, David (JLab)

  1. Announcements
    • Jlab staff is moving today from F-wing down to A-wing first floor in Cebaf Center
  2. Action Items
    • See e-mail from Hamamatsu
    • (Elton) Communicated with Hamamatsu regarding max ratings on the MPPCs. The danger is high currents, which should be limited to less than 1 mA per sensor. Presently the LV channels provide up to 10 mA for ten sensors, which would limit the current for each MPPC to 1 mA if it was distributed equally. However the circuitry should be checked to see how this might affect a single channel in case of failures.
  3. FCAL
    • HDFCAL log book
    • (John) No new problems
    • Survey is installing the (permanent) beam pipe from the back of the dark room back to the west hall of the hall. When the FCAL carriage gets pulled upstream into place, an extension will be added to the back to transport the beam to the photon dump
    • The beam pipe will have a thin window downstream of the dark room, requiring hearing protection in that area
    • New students are on site and learning about the detector
    • Air conditioning unit has been plumbed into the dark room. The dark room is cool, in the 50's with the detector off. Will warm up slightly with the detector on. Adjustments will be made to keep the temperature at the operating temperature.
    • Environmental monitoring parameters are being made available in EPICS. This will allow systematic studies of pedestals, stability, etc.
    • (Elton) When is the VESDA system planned for installation? Interlock signals need to be provided to the VESDA system at that time.
  4. BCAL
    1. Status
      • (Will) We have moved from the north side to the south side and are in the process of checking status of all sensors.
      • We have identified three modules with problems. One has HV1 disconnected, one has HV2 not reaching its sense voltage and the third module has two blank channels.
    2. HDBCAL log book
      • Elton went over Mark's log entry, which shows that there are large timing shifts between different LED columns and that the timing varies as a function of time with a period of about 3 hours, which is the period of temperature variations in the crates, presumably reflecting ambient air conditioning cycles.
      • (Andrei and George) Changes could be due to poor grounding and power cycles
      • (George) Should also check if timing is correlated with trailing edge of 100 ns LED pulses. (Timing is continuous, so this may not be source)
    3. Plan
      • Fix modules
      • Check readout of TDCs
      • Check response at different chiller temperatures
      • Study cosmics
  5. Reconstruction and Simulation
    • Teigan has downloaded the virtual machine from the workshop and learning about BCAL reconstruction
  6. TDR update
    • BCAL - present version has been sent to Mike for review. There are known updates that will need to be made, but draft is useful in present form
    • FCAL - Matt will work on this next week
  7. Calibration
    • (Manuel) Considering using thru muons to calibrate the block response.
    • (Matt) Single cosmics only deposit about 30 MeV of equivalent energy, so may be difficult to use as calibration. First the gains will be modified to smooth out the response from LEDs.
    • (Elton) could consider using Michel electrons from muon decay. We will try to do this for the BCAL.
  8. Any other business