Dec 17, 2009 Readout

Teleconference Time: 11:00 a.m. EST

• ESNET and EVO session
• 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. Order prototype light guides (Elton)
2. Determine the amplitude vs Npe for the light sensors (Carl)
3. Testing of new modules to determine the range of phoelectrons expected.

Documents to Review

1. Plan for SiPM Testing (Carl and Fernando)
   • Summary of the BCAL Readout Tests Using SiPM Arrays
   • Report on Hamamatsu MPPC arrays
   • Stress Test of Hamamatsu MPPC array
   • MPPC Irradiation Test

Tentative Agenda: Internal Review of SiPM Option

1. Announcements
2. Review of Action Items
3. Overview (Elton)
   1. Segmentation for all SiPM option Number of SiPMs = (24+16)*2*48 = 3840
4. SiPM - update
   1. Electrical Tests (Fernando)
   2. PDE/Dark Rate (Carl)
   3. Acceleration Tests (Carl)
   4. Tests still planned
5. Detailing the SiPM option
   1. Light collection and dynamic range (number of photons expected per sensor)
   2. Cooling / temperature stabilization (specifications)
   3. Output (gain and PDE) stabilization and summing
   4. Geometry model
6. Discussion - path forward
   1. Baseline Schedule
7. Discussion - MOU with USM

Minutes

Attending: Matt, Ryan (IU); George, Zisis (UofR); Beni, Elton, Eugne, Carl, John, Chuck, Tim, Mark, Howard, Stepan, Fernando

1. Announcements
2. Review of Action Items
   • Carl updated the amplitude vs incident photon plot in his slides. He has not yet extended the measurement to higher light yields where saturation is expected.
3. Overview (Elton)
   1. Segmentation for all SiPM option Number of SiPMs = (24+16)*2*48 = 3840
4. SiPM - update
   1. Electrical Tests (Fernando)
   2. PDE/Dark Rate (Carl)
      • Output variation of SiPMs across the sensor is a concern, as well as how to adjust initially. One option is to use adjust bias on electronic boards with resistor dividers. Howard pointed out that optical filters can also be used (by reducing light to sensor), and the filter could move with the sensor.
      • Eugene: temperature compensation system will need monitoring
      • Stepan: Temperature stabilization of the forward calorimeter uses both liquid and dry N2. Stability is better than 0.2% and runs at 17deg C.
   3. Acceleration Tests (Carl)
      • Radiation: Dose delivered using a 137 Cs source. Should add a temperature monitor inside the box for later reference.
      • Sensitivity to Hadronic radiation: Stepan to provide information on damage to SiPMs during NH3 pol target run.
   4. Tests still planned
5. Detailing the SiPM option. Most of the following items were discussed during the course of the presentations.
   1. Light collection and dynamic range (number of photons expected per sensor)
   2. Cooling / temperature stabilization (specifications)
   3. Output (gain and PDE) stabilization and summing
   4. Geometry model
   • Most of these items were discussed during the course of the presentations.
6. Discussion - path forward
   1. Baseline Schedule. It appears that the baseline project of the project allows for a year for start of SiPMs delivery and one year for testing before they need to be mounted on the Bcal modules.
7. Discussion - MOU with USM
   • Not discussed due to the interruption of network connections.