Aug 26, 2010 Readout

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Teleconference Time: 11:00 a.m. EST

  • ESNET and EVO session
  • Phone in CC L207 is 757-269-7084
  • 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. Testing goals and setup (Serguei)
  2. Will to find out if there is any feedback from USM on terms and conditions from our procurement package.
  3. Will to update statement of work for USM contract and develop detailed schedule.
  4. Collect this information of testing on the wiki for ease of presenting information. (USM)

Documents to Review

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Update - USM
    • SiPM test stand (Alam)
    • Status of statement of work (SOW)
  4. SiPM Radiation Hardness Test (Update from Yi)
  5. Electronics/cooling
  6. Geometry
  7. Simulation runs
  8. Cosmic-ray setup at UofR
  9. Light guides
  10. Collaboration Meeting (Five 25-min sessions allocated), some topics...
    • SiPM report
    • Bcal construction
    • Fcal construction
    • Preparations at USM
    • Decisions: Fcal insert, monitoring/calibration

Minutes

Attendees: Eugene, Beni, Yi, John, Elton, (JLab), Andrei, Zisis (Regina); Will (local), Alam (USM); Zisis, Andrei (UofR);

  1. Announcements
  2. Review of Action Items
    1. Will to find out if there is any feedback from USM on terms and conditions from our procurement package.
      • An agreement was reached between the Basal Grant and the university (USM) that the grant will carry any risks associated with accepting JLab procurement condtions. This is allow procedures to move forward at contract time. This agreement was reached at the time the MOU was signed.
  3. SiPM Radiation Hardness Test (Update from Yi)
    1. The wiki page has been reorganized, and plots have been updated with corrections factors for the neutron probe.
    2. The estimated lifetime of SiPMs at this time is about 8-9 calendar years (at 10^8/s). However, this estimate includes an extension of the lifetime of a factor of 2 (annealing) and additional factor of 3 for running at 5deg C. Both factors will be checked on irradiated samples when new samples are received from Hamamatsu in a couple of weeks. (Yi will remind Hamamatsu that the schedule for receiving the samples is very important to us).
    3. Data files from Carl has allowed Yi to fit for the dark rate.
      • Increase in dark current is consistent with the dark rate. Also, the estimated cross talk is extracted and about 13-15%.
      • Gain of samples remains unchanged.
      • The revised estimate for the dark rate of "outlier" 1x1 mm2 sample irradiated in Hall A gives a factof of 2.4 larger rate than other samples. This is lower than originally estimated. (Note that the plots on the wiki page used different pre-amplifer factors for the three plots, which is indicated in the comments).
    4. Carl will measure the variation of dark current across the irradiated arrays to check for uniformity. This is waiting on electronics from Fernando?
  4. Update - USM
    1. SiPM test stand (Alam)
      • Electronic (bare) boards for testing the dark current and SiPM signals have been fabricated (visually verified on video). Each board will allow readout all cells (16 chanels) from one array. (Alam could you verify this number?)
      • Boards need to stuffed (~1 week). Major components are in hand, some additional connectors can be added later.
      • The boards will check that signals (first with oscilloscope, later with ADC).
      • The boards will then check that accurate measurements of dark current can be made (requires careful control of environment, humidity, etc)
      • Adjustments to the boards may be necessary before producing more boards.
    2. Status of statement of work (SOW)
      • No update.
  5. Electronics/cooling
    • no update
  6. Geometry and light guides
    • no update
  7. Simulation runs
    • Computer runs have been completed (reported at previous meeting) and results are being used in the analysis of CR data
  8. Cosmic-ray setup at UofR
    • Data taking has been completed in the end of this week. Fitting of center point has been performed, but a combined fit to all data sets is in preparation. Simulations from Irina show that DeltaE from 2x2 area is about 12 times more than from the single fiber. VERY PRELIMINARY (NOT FOR ANY KIND OF REFERENCE!) Npe fit gives about 10 times more photoelectrons than we had from single-fiber test with Sr90 (with 20-25% error on the value). Assuming a 90% transmission of light guides, it looks like the module light output is consistent with extrapolations from single-fiber measurements though it's necessary to finish the analysis to make any certain conclusion. After the analysis will be finalized, the results will be reported next week at the cal WG and/or at the collaboration meeting.
  9. Collaboration Meeting (Five 25-min sessions allocated), some topics... Elton will propose time allocations for discussion next week at the cal WG.
    • SiPM report
    • Bcal construction
    • Cosmic-ray measurements (Andrei)
    • Fcal construction
    • Update on Bcal reconstruction
    • Comparison of light transmission of light guides (Athens)
    • Preparations at USM
    • Decisions: Fcal insert, monitoring/calibration