April 26, 2011 SiPM Electrical and Cooling

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Action Items from previous meetings

  1. Determine if swapped bias pins was accidental or in design (Chris)
  2. Develop front and back views of jumper sheets. Also get latest version of drawings (Jack)
  3. Request Hamamatsu data sheets from Chile to be used as input to jumper settings for boards (Elton)

Tentative Agenda

  1. Announcements
  2. Action Items
  3. Schedule, reporting, and manpower (Elton)
  4. SiPM production testing (everyone)
  5. Mechanical assembly (Scot)
  6. Mechanical (Jim)
  7. Mechanical drawings (Chuck)
  8. Temperature compensation (Jack)
  9. Preamp-summing (Chris)

Minutes

Attending:

  1. Announcements
  2. Action Items
  3. Schedule, reporting, and manpower (Elton)
  4. SiPM production testing (everyone)
    1. Mechanical assembly (Scot)
      • Cover plate has been installed and looks good
      • Damaged cable connections have been repaired
    2. Testing (Yi)
      • Checking of new hardware is underway. Is almost ready
      • Bobby and Tom went through a training session on Monday.
      • Elton has prepared a Pansophy checklist/traveller for the SiPM testing procedure
      • After putting on final touches, Bobby should start the testing
      • Testing will start at about 10 deg C.
      • Tests at lower temperature will require conditioning the air in the dark box. Fernando suggested some AC units based on Peltier coolers, which he will investigate as an option.
  5. Beam Test (Elton)
    • See Beam test Log Book for details
    • First chiller failed on Sunday by cooling continuously. Cooling plates were chilled to 1.5 deg C. Condensation found covering the cooling tubes. The electronics seemed to be dry due to the nitrogen flow.
    • Upstream and downstream assemblies were taken out, dried and reinstalled.
    • Tom found a new high capacity chiller and installed it. It is plugged into a remotely controllable power strip installed by Yi.
    • The circuit breaker with Hall B beamline equipment and the new chiller tripped yesterday. The chiller was plugged into a new circuit and left running at noon.
    • Based on the temperatures of the cooling plates, it appears that the chiller has tripped, although the power strip is still on.
    • Scot may have found the problem with the original chiller. Will confirm tomorrow. It may be returned to the hall if problems persist with the new chiller.
  6. Mechanical (Jim)
    1. Light guide templates were ordered on Monday. Expect 2 week turn around time
  7. Mechanical drawings (Chuck)
  8. Temperature compensation (Jack)
  9. Preamp-summing (Chris and Fernando)
    1. Procurement Decisions and timeline (should be completed by end of May)
      • Precision thermistor resistors have at least a 10 week lead time.
        • Will evaluate the SiPM samples already delivered to JLab and USM to determine the range or resistors required
        • If entire set is consistent, we will inquire from Hamamatsu whether they expect any differences from new batches.
      • Ringing on outputs
        • Scope checks seem to show that the ringing is greatly reduced with optimized circuits
        • Need to verify the wave forms with the beam test data
      • Gain resistors
        • Beam test data will also help us determine the operating point above breakdown (SiPM gain) and required ADC gain settings to match the FADC dynamic range.
  10. Light Guides
    1. Jigs for gluing have arrived and need to be checked out
    2. The clean tents need to be setup in the ESB and plan for production testing.