Feb 10, 2011 Readout

Teleconference Time: 10:30 a.m. EST

• ESNET 8542553 and EVO session
• 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
• Phone connection only upon request.
  • +1-866-740-1260 : US+Canada
  • +1-303-248-0285 : International
  • then enter participant code: 3421244# (remember the "#"). P
  • or www.readytalk.com (and code without the #)

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, JLab, Regina)
2. Detailed schedule for testing at USM (Elton and Will). In progress
3. Determine total need of light guides for work at UofR, Athens and JLab (Elton, Zisis, Christina).
4. Update on simulation with summed cells (Andrei and Irina)
5. Update Document Control at JLab with signed copies of QA (UofR), QC/QA (IU), and procedures for signoff of non-conforming items (Elton and Tim).

Tentative Agenda

1. Announcements
2. Review of Action Items
3. USM update
4. SiPM update
   • First Article testing (Carl and Yi)
   • Regina preparations
5. Simulations
   • Statistics of pi0 and etas for Bcal calibration Elton
6. Electronics/cooling
7. Geometry and light guides

Minutes

Attending: Elton, Yi, Fernando, Beni, Tim, Eugene (JLab); Will (USM); Zisis, Andrei (UofR).

1. Announcements
2. Review of Action Items
   1. Light guides: UofR requested 15, Athens requested 15. JLab will need 80 to instrument both sides of a calorimeter module.
   2. Will asked what sizes are needed for UofR and Athens. Zisis will revisit this
   3. JLab will need twice the full set of 40 guides (4x20 types). Elton mentioned that it might make sense to request this quantity as part of a first article on the light guide procurement.
3. USM update (Will)
   1. Making good progress on many fronts. The university is closed for a month of summer break. However, the Center continues to work with Iñaki, Alam and new technician.
   2. Light box is under construction (intend to weld next week, instead of screw)
   3. Prototype electrical board II: Alam estimates it is 80% complete. Final selection of buffer for amplifier is required. Likely sent to China for manufacturer.
      • Elton offered that Fernando could review the schematics. Will to check if he wants us to do this
   4. Light guides: rooms for prototyping and production are being reconfigured, which will allow installation of the large CNC machine. USM infrastructure group has the design and will provide a quote in 5 days.
   5. Hamamatsu has been contacted for a quote to respond to JLab. USM will have to take responsibility for shipping FOB New Jersey. Quote will be for > 2800 units. Hamamatsu has indicated that the price per unit will not change beyond that amount. USM is contemplating he purchase of additional units beyond the Jlab requirement.
   6. Elton said that JLab procurement is close to issuing the RFP to Chile.
4. SiPM update
   1. First Article testing (Carl and Yi)
      • Yi has ordered some parts and all have been received.
      • All labview drivers have been written, but test lacks integration
      • Confidence that the setup will the ready before first article units arrive.
   2. Regina preparations
      • Laser head was sent yesterday for repairs. Expect return from Germany in about a month.
      • Test setup is being reactivated and will be checked with existing SiPMs.
5. Simulations
   1. Regina: Irina has run two configurations a) unsummed b) 2x4(inner) + 2x2(outer) configurations.
      • There are questions about the output, and comparisons with IU results are in progress
      • Andrei will report at the cal working group meeting when IU is present to discuss their initial data on energy resolution and other results.
   2. Statistics of pi0 and etas for Bcal calibration Elton
      • Elton ran bggen to obtain some estimates of the expected statistics for pi0 and eta production for Eg>0.5 GeV, which might be useful for Bcal calibration.
      • The estimates are 16 M pi0 and 3 M etas with both photons in the Bcal and Eg>0.5 GeV in 10 hours or data at 10^7/s.
      • Eugene: Noted that there are factors that will reduce these numbers for a realistic analysis
      • Will: Number of photons at the upstream end may be relatively small. It would be useful to plot the angular distribution.
6. Electronics/cooling (Fernando)
   • Optimizing the front-end
   • Goal is to produce amplifier with very low noise. Individual cells have a capacitance of 5.1 nF, array capacitance is 320 pF.
   • Successfully imported board outline from mechanical drawings
   • Geometrical constraints on connectors at the inner part of the wedge are very tight and may need adjustments. The support structure including cooling tubes may need to be revisited.
7. Geometry and light guides
   • Zisis: Noted that the light guides may require features machined for attachment of the monitoring system. For example, one might need to drill a hole to insert light fibers.
   • Will: It would be most efficient to add these features during fabrication.
   • Andrei added some details regarding his tests:
     • Small 1 mm hole, 2.5 mm deep was drilled into the side of a WC. A short fiber piece was glued into the hole and the other side was glued to the LED. LED was flashed at a bias of about 9.3 V (relatively low). Signal at far end was 4.5 V. Signal at near end was 2 V. The large pulses give us plenty of room for adjustment.