Nov 4, 2010 Readout

Teleconference Time: 11:00 a.m. EST

• ESNET 8542553 and EVO session
• Phone in CC L207 is 757-269-7084
• Phone in the Regina Videoconference Suite is 306-585-4204
• 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. Collect this information of testing (including goals and setup) on the wiki for ease of presenting information. (USM)
2. Resolution including summing SiPMs (IU)
3. The JLab team should seriously consider a NIM article for the extensive work on SiPM radiation hardness. Yi will prepare a draft

Tentative Agenda

1. Announcements
2. Fcal calibration
3. Review of Action Items
4. Update - USM
5. SiPM Radiation Hardness Test (Update from Yi)
6. Electronics/cooling
7. Geometry and light guides
8. Monitoring system
9. Simulation runs

Minutes

Attending: Elton, Beni, Chuck, Tim, Fernando, John, Eugene (JLab); Matt (IU); Zisis, Andrei (UofR); George, Christina (Athens); Will (USM)

1. Announcements
2. Fcal calibration
   • Due to a late start, this discussion was postponed to next week. For an advanced view of the work see e-mail from Zisis
3. Review of Action Items
4. Electronics/cooling (Fernando)
   1. Organizational meeting at JLab with detector group to discuss the project. New EE (Jack McKisson) will assist with the temperature feedback board. Chuck and Tim will work on the mechanical cooling.
   2. First article units (80) are expected in February. Fernando is preparing a 16-channel test circuit for testing that reads out individual array cells and can be used to study uniformity. This circuit board can be made available to Regina and USM for additional testing.
   3. Issues that need resolution
      • Light guides: we made the decision that the nominal design will have the trapezoidal light guides. Studies to refine the shape will continue: a) size of output (optimization of collection through air gap into SiPM array), b) flat section at base where they will be glued together (cross talk). [Note by Zisis: KLOE had a 3 mm connection between bare light guides and did not find that cross talk was a problem.]
   4. Additional testing
      • Zisis: New master's thesis student on board, who will study SiPMs. Katherine, taking some leave from present job, is helping revitalize the test setup. Currently using the Hamamatsu and SensL test arrays. Laser head needs replacing. The xy scanner is being outfitted to use an LED, which can perform relative measurements across the SiPM array, while the laser is out of commission. Source measurements with 90Sr are also planned.
      • Elton will check if a spare SiPM array can be lent to USM
5. Geometry and light guides
   • Light guide measurents are being refined, but results are not expected to change. Athens has been using a "thin" (3 cm long) baby cal. Zisis is preparing a longer (~30 cm) baby cal for further studies.
6. Testing of cal modules at JLab
   • Extent of testing of modules that have arrived from JLab is under discussion. Zisis reminded us that they have setup a testing procedure to determine relative light transmission throught the modules that was used initially to check the first machining at ROSS. However, measurements of other modules are not conducted due to the difficulty of performing them at ROSS. However, such a system could be transfered (either physically or as a design) for similar measurements at JLab.
7. Update - USM
   1. Discussions of the sow are ongoing offline
   2. Current concept is to have a single contract covering all work at USM
   3. Tasks under discussion are
      • light guides. USM is purchasing a new large CNC machine which could be used for this purpose
      • testing of individual SiPMs. Received 1 of 8 prototype boards, 40% stuffed. Goal is to have one channel completely operational soon.
      • testing of assembled electronic wedge boards including sensors. There is a concern that a complete assembly with sensors is relatively fragile and should not be transported. Also, the design of this system is still developing, so there is insufficient information to make detailed estimates of the effort an time to complete. The suggestion is for JLab to order electronic boards and mechanical cooling infrastructure, and have the attachment of sensors be done at JLab. USM is willing to send some manpower to JLab to assist in this task.
      • testing of discriminator boards. This might be done in conjunction with other halls, such as Hall B, that will also use the discriminators.
   4. Refinement and discussion of the USM effort and division of responsibilities between JLab and USM will continue offline.