May 20, 2010 Readout

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Teleconference Time: 11:00 a.m. EST

  • ESNET and EVO session
  • Phone in CC F326 is 757-269-6337
  • Phone:
    • +1-800-377-8846 : US
    • +1-888-276-7715 : Canada
    • +1-302-709-8424 : International
    • then enter participant code: 77438230# (remember the "#"). Phone connection only upon request.

Items for followup from previous meeting

  1. Serguei agreed to send out a testing proposal for comments, including preliminary circuit designs and list of available equipment at USM for reference.
  2. Start a bulleted list of testing for the SiPMs (Serguey).
  3. Distribution of p.e. corresponding to each sensor within the readout sum (Andrei). Add min and max for both upstream and downstream readouts.
  4. Will to find out if there is any feedback from USM on terms and conditions from our procurement package.
  5. Complete full circle of sending STP files back and forth between USM and JLab to verify compatibility.

Documents to Review

  • GlueX-doc-1474 BCAL Dynamic Range from the Simulation with FLUKA
  • GlueX-doc-1432 Trapezoidal guides for the light collection for SiPMs (Fig 22)

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Update - USM
  4. USM MOU/contract update (Elton)
  5. Simulation runs
    1. Media:dynamic_range.pdf Estimates from GlueX-doc1474 (Elton)
      • Air gap between guide and SiPM results in a ~50% loss of light (GlueX-doc-1432 Fig. 22).
      • Saturation in SiPM: N_fire/N_pe ~ 1 - f/2, where f = N_pe/N_pixels.
  6. Geometry
  7. SiPM Radiation Hardness Test (Yi)
  8. SiPM - Testing Schedules
  9. Light guides

Minutes

Attending: Yi, Pedro, John, Beni, Elton, Fernando, Eugene (JLab); Zisis, Andrei (USM); Will, Serguei, Alam (USM).

  1. Announcements
  2. Review of Action Items
    • Files from JLab read successfully at USM. We should verify the inverse. Alam inquired about the version of STP files (300 vs 314). Need to inquire from Chuck.
  3. Update - USM
    • Made prototype light guide with new CNC machine (shown at previous meeting)
    • New mech engineer (Iñaki) has joined and is doing very nice work
    • Alam is working on the circuit board for testing 16 SiPMs. Pictures will be shown next meeting. About 75% of electrical design complete, 100% of the preliminary mechanical (light guide, pulsing system, support for SiPMs)
    • New equipment from CAEN has arrived and is being installed
    • A computer cluster with CAMAC and VME crates is being hooked up to run their DAQ. Data can be made available for study. Remote control of equipment is also possible. Data files will likely be in ROOT format.
  4. USM MOU/contract update (Elton)
    • (Almost) final version of MOU is circulating at JLab through the concurrence chain. Should be ready for USM signatures next week.
  5. Cosmic-ray setup UofR
    • Setup to measure no. of pe. using cosmic-rays this summer. Will be able to make measurements with both PMTs and SiPM arrays.
    • Fernando: Has asked Carl to measure response of SiPMs to fiber output (LED measurements are of course already in hand).
  6. Simulation runs
    1. Media:dynamic_range.pdf Estimates from GlueX-doc1474 (Elton)
      • Air gap between guide and SiPM results in a ~50% loss of light (GlueX-doc-1432 Fig. 22).
      • Saturation in SiPM: N_fire/N_pe ~ 1 - f/2, where f = N_pe/N_pixels.
    2. Andrei will check Elton's numbers in the table and provide feedback.
  7. Geometry
  8. SiPM Radiation Hardness Test (Yi)
    • Fit to exponential + constant. Recovery is 8-10 day periods
    • Approximately 1/2 damage is permanent (constant term)
    • Gain seems to recover to original value.
    • Serguei: Radiation damage appears very similar to APD radiation damage. Can check CMS references for discussion.
    • Discussion: Fernando brought up the possibility that the increase in dark current may be due to larger amount of leakage currents (as opposed to an increase in dark rate)
    • Suggestion: Use a 1x1 mm2 SiPM to record dark rate and dark current, then irradiate in Hall A (previous measurements indicate that they do not even have to be powered) and check dark current and dark rate after irradiation.
  9. SiPM - Testing Schedules
    • no update
  10. Light guides
    • no update