July 29, 2010 Readout

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)
2. Will to find out if there is any feedback from USM on terms and conditions from our procurement package.
3. Will to update statement of work for USM contract and develop detailed schedule.
4. Collect this information of testing on the wiki for ease of presenting information. (USM)

Tentative Agenda

1. Announcements
2. Review of Action Items
3. Bcal thresholds and resolution at low energies (PDF Slides) (Matt)
4. SiPM Radiation Hardness Test (Update from Yi)
5. Geometry
6. Light Guide Gluing (Chuck)
7. SiPM positioning (Chuck)
8. Update - USM
   • Status of statement of work (SOW)
9. Simulation runs
10. Cosmic-ray setup at UofR
11. Light guides

Minutes

Attendees: Yi, Fernando, Beni, John, Elton, Eugene, Chuck (JLab); Matt, Dan (IU); Andrei, George (UofR); Pedro (USM).

1. Announcements
2. Review of Action Items
3. Bcal thresholds and resolution at low energies (PDF Slides) (Matt)
   • Model resolutions using MC reconstruction
   • Use old geometry (no summing, inner segments SiPMs, outer segments FM pmts)
   • Optimistic, since summing will likely degrade performance. Dan is implementing the new scheme and will rerun programs when complete.
   • New normalization comes from Andrei, corresponds to 165 photons/MeV in fiber/side compared to nominal 75 photons/MeV in fiber/side.
   • Results show that a factor of 10 increase in dark current changes resolution sigma by about a factor of 2.
4. Estimation of Cross Talk GueX-doc-1553 (Yi)
5. SiPM Radiation Hardness Test#Test with RadCon AmBe Source (Update from Yi)
   • See page for details. Radiation tests with RadCon calibrated AmBe neutron source (En ~1-10 MeV).
   • SiPM Radiation Hardness Test#Fluence simulation of Hall D gives an estimated 6.5 years for SiPMs (at 10**7 s/year) to increase dark rate by a factor of 10.
   • One anomalous 1x1mm2 cell irradiated in Hall A shows a dark rate increase by factors of 4 higher than other measurements and needs checking.
   • Additional checks needed:
     1. Check annealing time for 1 and 9mm2 units irradiated with RadCon source
     2. (Beni) Check if increasing temperature helps annealing process
     3. Check temperature dependence of annealing
     4. (Eugene) Silicon micro-strips at CERN are kept cold ( about -70 deg) to increase radiation hardness from krad to Mrad. (Freeze out defects?) It is worth understanding the mechanism.
6. Geometry
7. Light Guide Gluing (Chuck)
   • Check options for gluing guides on module before installation into magnet
   • Consider not gluing guides to each other using a band to secure them at the base and the fitted plate with square holes at the other end.
8. SiPM positioning (Chuck)
   • Make window opening for sensor large enough so that it does not impede adjustment of distance between sensor and guide
   • Next: must design the gas volume for dry air (or nitrogen), as well as scheme to avoid problems with condensation.
9. Update - USM
   • No report.
10. Simulation runs
11. Cosmic-ray setup at UofR
    • Will complete tests with calibrated pmt
    • Next measure response using SiPM array, air gap with a) WC and b) trapezoidal guides