Dec 11,2012 Readout

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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 and Canada
    • +1-303-248-0285 : International
    • then use participant code: 3421244# (the # is needed when using the phone)
    • OR from type access code 3421244 into "join a meeting" without the # (you need java plugin)

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

  1. SiPMs (USM)
    • Provide histograms of all measured units for each specification at T=20 deg C and V=1.2 V above breakdown.
    • Show distribution of light guide measurements (Alam, Francisco, Iñaki)

Presentations from recent meetings

Tentative Agenda

  1. Announcements
  2. Review of Action Items
  3. Monitoring
  4. Update from USM
    1. File:Xtsudy.pdf
  5. Discussion and decision on Noise SiPM assignment
  6. Status of testing at JLab
  7. Status of testing at Regina
  8. Simulations
  9. Beam Tests, Cosmics
  10. Other


Attending: David, Yi (Jlab), Elton (GSI), Hayk (USM), Christina, Pavlos (Athens), Shaun, Andrei, Zisis (Regina)

  1. Announcements: none
  2. Review of Action Items: items have been dealt with and striken from the list above.
  3. Monitoring:
    1. FCAl first article: it has been received and preparations are underway for the measurements.
    2. BCAL: min boards procced as per plan and controllers are being stuffed by Kappos. Delivery will be after XMas. Christina will communicate with Elton to arrange the shipments in view of minimizing customs duty.
  4. Update from USM: Hayk showed Orlando's histograms on the dispersion and magnitude of the cross talk. The former quantity is unaffected by over bias (1.0, 1.1 and 1.2 V distributions are quite similar) but the magnitude climbs from 18-25%. This is in agreement with JLab measurements. With all factors considered, it was decided to have Vob=1.0V as our starting point (at the 20 C of our initial test) and tweak later based on our experience looking at showers. 0.9V is good for 20 C, but 1.0 V satisfies all lower temperatures.
  5. Discussion and decision on "noisy" SiPM assignment: following discussion, we all agreed that the "noisy" SiPMs be treated as all the rest, for three reasons: a) it is hard to see from the plotted distributions where to put a cut on the dark rate, above which a SiPM is considered "noisy", b) after irradiation the dark rate climbs to 100 MHz making the noisy 40MHz (divided by 3 for cool operation, ie down to 10-13MHz)a moot point and c) logistically for the SiPM and electronics maps and assembly this would add more work and possibly lead to errors. Decision: treat all SiPMs (including abnormal ones with one cell off) the same.
  6. Status of testing at JLab: no report.
  7. Status of testing at Regina: Shaun will work on IV and PDE measurements starting next week and for the month of January, using the laser and the 10 first article MPPCs.
  8. Simulations: Andrei will wrap up the sampling fraction simulations by the end of the year and send to David. David reminded us that his changes are not set as default. When they are implemented they would not affect the data challenges but would affect reconstruction such as Paul M's. The changeover has to be coordinated with the Physics and Software WGs.
  9. Beam Tests, Cosmics: no report.
  10. Other: no other business.