Revision as of 09:44, 18 June 2010

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) - addressed in agenda below
2. Will to find out if there is any feedback from USM on terms and conditions from our procurement package.
3. Investigate options for robust mechanical and electrical connections of SiPMs to boards during testing and production (Fernando)
4. Send thermal properties of the SiPM casing to Serguei (Fernando)
5. Collect this information of testing on the wiki for ease of presenting information. (USM)

Documents to Review

Tentative Agenda

1. Announcements
   • Elton is out this week. Zisis will lead the meeting.
2. Review of Action Items
3. Update - USM
   • Test plans from Sergey K.
   • light guide shipment status - "your check is in the mail"
     • Photo 1
     • Photo 2
     • Photo 3
4. Simulation runs
5. Cosmic-ray setup at UofR
6. Air gap measurements at UofR Media:AirGapTest.jpg
7. Geometry
8. SiPM Radiation Hardness Test (Update from Yi)
9. SiPM - Test Electronics (Fernando)
10. Light guides

Minutes

Attendees: Beni, Yi, Fernando, Chuck (JLab), Will, Alam, Sergey@CERN (USM), Andrei, Zisis (Regina)

1. Announcements: none
2. Review of Action Items:
   • Will reported that the USM MOU is imminent and that the contract boiler plate was shown by the director of graduate studies to the lawyers who suggested that it passed on to the Valparaiso Center for Technology that has experience in dealing with such contracts, and this is doable under the USM-Valparaiso bi-lateral agreement. The idea of having a look at the boiler plate in advance was a very good one.
3. Update - USM
   • Serguei gave a presentation (see link above in the Agenda) on the SiPM/MPPC plans for testing. Some thinking still needs to go on the number of points to measure (e.g. temperatures), but the current plan can handle up to 500 SiPM arrays in a month. Measurements on the 3x3mm2 SiPMs were shown, and notable was the 15% cross talk which is higher than what Hamamatsu claims. No after-pulsing effect seemed noticeable. The information will be transferred to a Wiki in the future.
4. Simulation runs: nothing to report.
5. Cosmic-ray setup at UofR: as of last night, the cosmics runs started. There should be a preliminary report at next week's Calorimetry video conference.
6. Air gap measurements at UofR Media:AirGapTest.jpg: The left plot is with optical grease and the right one with a 1.5mm air gap; the spacer had a 2cm opening so the geometry favours these measurements over a SiPM placed with a 1.5mm gap. Two Hamamatsu calibrated PMTs were coupled to the Construction Prototype, through 2x2cm2 viewing ports. An Athens LED was placed on the Winston Cone of one, and the air gap test was done on the opposing (far end) PMT. About 50% loss of light is observed between air gap/optical grease between Winston Cone and far end PMT window.
7. Geometry: Chuck asked about the trapezoidal light guides. Zisis said that the air gap measurements can be repeated with those, when they arrive from Regina. (Chile has sent them). Discussion ensued on the fastening of the 40 light guides as a unit and then gluing to the module. Serguei suggested a reflective material from VM2000 (now VM) and will send a link with this information. Yuri Sharabian in Hall B has worked with it, and it seems promising.
8. SiPM Radiation Hardness Test (Update from Yi) - Yi updated the fact and conclusions on his Wiki page. 50% recovery in DR in 10 days. Pavel was asked to simulate the Hall A setup more realistically. An Americium-Beryllium source will be borrowed from RadCon (they use this to calibrate their neutron detectors) whose dose is know and we can use that to understand the neutron fluence. The CERN report had 10^10 fluence but this included neutrons and gammas. Serguei suggested looking at long time duration (1.5 milli sec) for very large pulses in the SiPMs, as seen at CERN. It is supposed that these are due to n-alpha reactions.
9. SiPM - Test Electronics (Fernando): Information (tolerances, materials) regarding action items 3 and 4 were sent by Fernando to Serguei on the connection sockets. The pin diameter falls in the middle of the range of tolerance/acceptance of socket. The three finger arrangement is good. Beryllium-Copper is used, which has good elasticity and springiness. It should tolerate many many couplings and re-couplings without any Cu removal.