Jan 24, 2012 Readout

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 www.readytalk.com type access code 3421244 into "join a meeting" without the # (you need java plugin)

Participant Direct Lines

• JLab Phone: in CC F326 is 757-269-6337 (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. Understand differences in PDE measurements between JLab, USM and UofR. Full discussions underway

Presentations from recent meetings

1. Update from USM at Bcal Readout Meeting
   • SiPM testing
   • Light guides
   • Station 2 report
   • Production Manager Report
2. Presentations at Cal Working Group Meeting
   • Characterization studies of silicon photomultipliers NIM A620 (2010) 217 (Link for JLab)
   • Key Figure 8
   • PDE measurement update at USM
3. Presentations at PDE Discussion on Jan 20
   • SiPM PDE extraction at Regina
   • Comparison of PDE measurements in literature (Elton)
   • Comparison of Current vs Rate (Yi)

Tentative Agenda

1. Announcements
2. Review of Action Items
3. Update from USM
   1. run manager report
   2. Gain comparisons
4. USM Web Interface to DB
5. Discussion of PDE measurements
6. Status of Testing at JLab
7. Other

Minutes

Attending: Javiera, Hayk, Will, Serguei (USM); Elton, Yi, John, Beni, Tim (Jlab); Zisis, Mehrnoosh, George, Andrei (UofR); George, Pavlos, Christina, Stratos (Athens)

1. Announcements
2. Review of Action Items
3. Monitoring (Athens)
   • Kappos has finished the design for the Bcal boards. They will send the design to JLab later today or tomorrow.
   • The Fcal design should be completed on Monday.
   • Elton said that Christina should go ahead and submit an invoice for this milestone, so that it can proceed in parallel with the submittals.
   • Samples of flexible cable pcs are being ordered from two companies with large cost difference to see if the lower cost company is acceptable.
4. Update UofR
   • Mehrnoosh has started PDE measurements with the laser and a 120 ns gate. They will be reported soon
5. Update Jlab
   • SiPM production testing is nearly ready
   • One of four boards is mounted, software is almost ready. Additional transition boards to ADC also need to be populated.
6. Update from USM
   1. run manager report
      • All first-article SiPMs have been measured in the stage 2 setup
      • Number of boards per day has been tracked and the time has been reduced to allow about 5 tests per day
      • Expect to have 40 units tested by the weekend.
      • Thermisters in stage 3 setup were calibrated last week. Found some burned out amplifiers and replaced.
      • Two MPPCs arrived with bent pins. Hamamatsu should be notified and requested to improve their packing and replace the two damaged sensors
      • Second shipment of SiPMs is in customs in Santiago.
   2. Gain comparisons
      • Plots show gain measurements with station 3, giving G~7-8x10^5. Fluctuations across cells is likely due to amplifier gain determinations
      • The overvoltage used by USM is 71.1 V (20 deg) vs Hamamatsu Vop = 72.6 (25 deg) ~ 72.3 V (20 deg). These differences do not make sense as the Hamamatsu voltage, as determined by JLab, is 0.9 V above breakdown.
      • The JLab PDE measurement for a gain of 7.5x10^5 is 27%, very close to the USM measurement. However, note that the USM PDE measurement was performed in station 2 and the gain measurement in station 3, which could have systematic differences.
      • Checks are ongoing.
      • Elton: Asked about the thermal contact of SiPMs to cooling plate in station 3. At the moment there is not contact, but tests are ongoing at 5 deg to check how important this is.
      • USM also has some measurements of cross talk (16-25%) and dark rate. However, the data are not yet in a form which is easy to plot. They will do this shortly.
7. USM Web Interface to DB
8. Discussion of PDE measurements
9. Status of Testing at JLab
10. Other
    • Elton asked if Zisis could run the Cal Working group meeting next Tuesday and he agreed. Thanks!