Dec 5, 2011 SiPM Electrical and Cooling

Action Items from previous meetings

1. Decide on cable connections for monitoring cable from Bcal wedge to patch panel. Consider electronics needed for pulsing system (Elton and Fernando) Decided to have a separate patch panel, which allows decisions on these other items to a later date
2. Make a metal die to punch holes in cooling mat to ease assembly. (Nick and Jim)
3. Give Jim a U-board with defective SiPM for devising extraction tool (Nick and Yi)
4. Determine granularity of LED bias and power, as well as multiplicity of trigger signals (Elton)
5. Check on official releases of the 3D model (Elton and Jim) All items will have a drawing. 3D models will be tagged in directories on the group disk.

Tentative Agenda

1. Announcements
2. Action Items
3. Schedule for production and testing (all)
4. mini-Bcal (Elton)
5. SiPM production testing (Yi)
6. Mechanical assembly (Jim)
7. Temperature compensation (Jack)
8. Electronic boards (Fernando and Chris)
9. Light guide gluing setup (Scot)

Minutes

Attending: Jim, Elton, Nic, Jim, Ivan, Yi, Chris

1. Announcements
   • No meeting till next year. Happy Holidays.
2. Action Items
3. Schedule for production and testing (all)
   1. Light guides
      • Approximately 1400 have been delivered and 400 more arrived today.
      • Manpower for the gluing has been identified, but will start the week before the break
      • Will check that tooling does the job and start some dry tests before starting. If necessary make any modifications to procedures/setup.
   2. Bcal assemblies (mechanical)
      • List and sequence of pre-assembly tasks was generated by Elton, Chris, Nic and Jim following the meeting proper (see next)
      • A better estimate for total time to complete the pre-assembly tasks is needed. However, it clearly needs dedicated manpower next month to complete the tasks by February
   3. List of mechanical pre-assembly tasks
      1. Fabricate Cooling Tubing Assembly (Note: fixturing is complete but not tested)
         • Cut
         • Braze fittings onto tube
         • Bend tube
         • leak test fittings
      2. Gluing
         • glue tube into cooling plate
         • glue thermistor onto boards
         • glue RTD assembly. (Note: Chris needs to provide RTDs with wires soldered already)
         • install 2 tube clamps onto plate
      3. Assemble/sort
         • insert threaded rods into spacers
         • sort hardware into labeled bins for use during assembly
4. mini-Bcal (Elton)
5. SiPM production testing (Ivan and Yi)
   • A/C unit has been installed and is working great. No condensation on cooling tubes at 5 degC. Note: RH~38% at 10 degC.
6. Mechanical assembly (Jim)
   • All (mechanical) parts are expected to arrive before the break
   • They still need to be sent out for anodizing. They will be sent out as soon as they come in.
   • There are still hardware items that need to be ordered from McMaster Carr
7. Temperature compensation (Jack)
   • Jack is planning to make the jumper maps next week.
   1. Sensors with high dark rate
      • A question was raised by USM on Tuesday on now to treat some sensors that have unusually high dark rate. They have identified about 25 such units so far.
      • We want to make a decision, so that Jack can make the final jumper maps.
      • Our tentative suggestion is to place the units with high dark rate in the outer layer in the sum of four. Elton will confirm this decision before next week.
   2. Numbering
      • Jack questioned how to number the electronic boards. One possibility was 1-96 with Up being odd and Down being even. A second possibility was U1-U48 and D1-D48.
      • Elton and Chris agree that the second option (U1-U48, D1-D48) was more natural. Will confirm with Fernando that we should go this way.
8. Electronic boards (Fernando and Chris)
   • Still waiting on the first article to arrive. We have the jumper maps for these boards.
9. Light guide gluing setup (Scot)