Jan 29, 2013 Calorimetry

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Teleconference Time: 11:00 a.m. EST

  • ESNET (Number is 8542553) and EVO 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 www.readytalk.com (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)

  1. Produce plots of SiPM parameters, such as the ones already shown, for Vover=1.0, 1.1 V (Orlando) Plots showed last week at the Bcal Readout meeting.
  2. After summary of SiPM parameters, provide data to Hamamatsu for comments (USM)
  3. Monitoring
    • Suggest a range of signals in mV required for the LED monitoring system. Establish expected operating range for pmts and signal size corresponding to shower energies. Could use the beam test data for this. (IU)
    • Investigate options for uniform monitoring light delivery (Athens)

Tentative Agenda

  1. Announcements
  2. Collaboration Meeting
    1. Friday February 22, 2013.
    2. 10:55 Session Ic (100) --- Calorimetry - (Organizer: Matt Shepherd) - Chair:
    3. Suggested topics (from Bcal readout meeting) are
      • Bcal production including testing
      • Fcal Update including lead glass stacking
      • Summary of SiPM testing (USM)
      • Monitoring (Bcal production and Fcal status)# Review of Action Items
  3. Monitoring: Media:UpdateFCALJan2013.pdf
  4. FCAL
  5. BCAL
  6. USM
  7. Simulations
  8. TDR update
  9. Calibration of Calorimeters
  10. Any other business


Attendees: Elton, John, Shaun, Beni, Yi, Eugene, David, Tim (JLab); Christina, Pavlos (Athens); Zisis, Andrei (UofR); Hayk, Orlando, Alam, Serguei (USM); Matt, Kei (IU)

  1. Announcements
  2. Collaboration Meeting
    1. Friday February 22, 2013.
    2. 10:55 Session Ic (100) --- Calorimetry - (Organizer: Matt Shepherd) - Chair:
    3. Bcal list confirmed during discussions. Move Christina to first talk
      • Monitoring (Bcal production and Fcal status) (Christina)
      • Bcal production including testing (Elton)
      • Fcal Update including lead glass stacking (Matt)
      • Summary of SiPM testing and Light Guide production (Hayk)
  3. Review of Action Items
  4. Monitoring: Media:UpdateFCALJan2013.pdf
    • 130 x 130 cm2 plexiglass sheet was blasted everywhere except about 10 cm from the edge to investigate response to LEDs
    • Measure with full Pb glass block and pmt and all LEDs and as a function of bias voltage. Good news!
    • Data with all LEDs seem to provide sufficient light output
    • Only central region could be measured with full Pg glass block. Small pmt used to complete more extensive scan.
    • Tentative proposal: use blasting over most of the surface and add black tape on edges to reduce sensitivity at edges.
    • Matt: Suggest to continue to investigate both uniformity and reproducibility of this approach.
    • Christina: also investigated the use of white LEDs. They are large in size and would require a complete redesign of the present board, so it is not promising.
  5. FCAL
    1. Stacking update (John)
      • 360 fully assembled and tested modules (>10%), which is about 10 layers
      • Upon reaching the max width of 59 blocks, survey and alignment will come in and check stacking up to that point.
      • First week with three persons (Manuel was away at start). The goal of stacking 100 bars per day is likely with three persons.
      • Shimming working well. Shims are 3 mils thick.
      • Eugene: Inquired about replacing pmt after stacking? A procedure has been developed that allows an "expert" to replace a pmt.
      • Matt: Asked about the amount of compression needed to insert the rubber padding at end? The movement is between 1/8 and 1/4, closer to 1/8. Tightening is presently done manually. Matt: Try to press onto fixed side during stacking to minimize displacement at end.
    2. FCAL Beam Test (Kei)
      • See also GlueX-doc-2118
      • Kei went over the slides and responded to comments/feedback
      • Eugene: The floor term of 3.5%, taken from the Radphi experience, is quite large for a prototype and may not be the best assumption.
      • Eugene: Also note that at low energy it appears that the stochastic term is dominant and can be determined mostly independent on assumption about the floor
      • Kei: Likely for the paper, only the data will be shown without parameterizations.
      • The intent is to circulate a draft NIM paper in about a week for comments
    3. Dark room (Matt)
      • Need a JLab review of the dark room drawings, especially approval for the cable load and welding procedures.
      • Tim: Will check with Chuck and clarify if any additional information is required from IU
  6. BCAL
  7. USM
    • Scratched MPPC's parameters File:ScratchedMPPCparameters.pdf, File:ScratchedMPPCparameters.xls
    • Scratched MPPC's have been retested and the data provided.
    • USM has not digested the information and will provide plots and conclusions at the Bcal Readout meeting.
    • Software result on scratched MPPC: 3922 File:ScratchedMPPCsoftware.pdf
    • Automatic scanning procedure has been developed that identifies fraction of active area on SiPMs from digital photograph.
    • Last shipment of 360 SiPMs has been returned to Hamamatsu. Serguei will send the tracking number to Elton (completed as of this writting).
  8. USM light guide production (reduced session following meeting)
    • Elton summarized the status of non-conforming light guides, which had been detailed in previous e-mails.
    • The first three non-conforming guides have been packaged and will be sent out as soon as JLab approves shipment.
    • USM will check the light guides and provide feedback on tolerances. A discussion on how to address the problem will follow.
  9. Simulations
  10. TDR update
  11. Calibration of Calorimeters
  12. Any other business