April 22, 2010 Readout

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. Fill out loan agreement for SiPM arrays at UofR (Elton).
3. Start a bulleted list of testing for the SiPMs (Serguey).
4. Dynamic range of signals to sensor and electronics (Andrei).

Tentative Agenda

1. Announcements
2. Review of Action Items
3. Update - USM
4. Simulation runs (Gluex-doc-1474)
5. Geometry
6. SiPM Radiation Hardness Test (Yi)
7. SiPM - Testing Schedules
8. Light guides

Minutes

Attending: Fernando, Beni, Sasha, Elton, Pedro, Tim (JLab); Zisis, George, Andrei (UofR)

1. Announcements
   • First four Bcal modules have been shipped and crossed over into US territory! Expected arrival on Monday.
   • Note: we did not have anyone connect from USM, although the EVO connection was live.
2. Review of Action Items
   • Elton will complete the loan request today
3. Update - USM
   • None
4. Simulation runs Gluex-doc-1474
   1. Andrei updated his presentation with new simulation results
   2. For the dynamic range determination: (All numbers correspond to the sum of three sensors)
      • Upper limit use 2.5 GeV photons centered on segment at 12 deg and downstream (max p.e. ~ 18k), use the inner most segment.
      • Lower limit use 0.06 GeV photons centered between segments at 105 deg and downstream (max p.e. ~ 50), but take max of any readout segment.
      • Dynamic range is threfore about 400. Absolute numbers need to be adjusted for lossed in the light guides and gaps during collection.
      • For complete characterization of electronics also need to know the distribution of p.e. corresponding to each sensor within the readout sum (Andrei will get this).
   3. Comment (Beni)
      • To cover the dynamic range of the Bcal, we should consider reading out each summed output with a two FADCs covering different ranges, one with a high gain (for small signals) and one with low gain (for large signals). This would add 48x2x4/16=24 additional FADCs to the system.
5. Geometry
   • Chuck has been in contact with Inaki on exchanging geometry files to clarify any discrepancies.
6. SiPM Radiation Hardness Test (Yi)
   • Elton summarized Yi's work while he was removing the irradiated sensors from Hall A.
   • Yi has done a beautiful job of collecting all necessary information related to the performance of the SiPMs in the radiation environment. Assessment of the amount of radiation to the detectors relative to what is expected in Hall D still needs some work.
7. SiPM - Testing Schedules
8. Light guides
9. Other
   • Fernando: The calibration plan needs to be firmed up, so that cables/fibers and any other inputs/outputs to the detectors can be incorporated into the mechanical design of light guides and electronic boards.
   • This should be discussed in more detail at the collaboration meeting.