July 26, 2011 SiPM Electrical and Cooling
From GlueXWiki
Action Items from previous meetings
- Develop front and back views of jumper sheets. (Jack)
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Check into AC units based on Peltier coolers for SiPM production tests (Fernando)See SRCOOL12K and MovinCool -
Review Fcal LED and controller monitoring boards (Fernando) -
Decide on size of overlap of voltage bins for the SiPMs (Yi and Jack) -
Complete molds for wrapping and order forms (Jim)Elton to test wrapping forms. -
Thermal mats need to be ordered (Jim said that Fernando or Chris will take care of this) -
Cooling tubes need to be brazed in (Jim?)Bending and brazing tubes in progress -
Circuit board and micro-Dsub connector for monitoring system needs to be completed (Chris and Jim)
Tentative Agenda
- Announcements
- Action Items
- Schedule, reporting, and manpower (Elton)
- SiPM production testing (everyone)
- SiPMs assignment for new boards
- Mechanical assembly (Jim)
- Temperature compensation (Jack)
- Electronic boards (Chris)
- Light guide gluing setup
Minutes
Attending: Elton, Fernando, Yi, Chris, Nick, Scot
- Announcements
- Action Items
- Schedule, reporting, and manpower (Elton)
- Light guide schedule: Two sets are promised for shipping tomorrow. Once in production, USM expects to be able to produce many sets per week.
- SiPM production testing (Yi)
- Ben St.Laurent has been analyzing the data that Bobby took
- All SiPMs are good except for one outlier
- The 3rd cooling plate was very noisy. It was possible to remove the systematic noise using the average over all tests.
- Comparison with the Hamamatsu gives confidence in the test data from Hamamatsu.
- Sixteen units with low PDE were found, but all measured in one batch. It is likely the testing had a problem and will be retested.
- Data taken on cross talk and afterpulsing, but it has not yet been analyzed
- Optimal bias voltage setting has been revisited. Original conclusions that showed a minimum at an overbias of 1.15 V was faulty. The corrected calculations show a slow improvement with voltage up to 2 V. The suggestion is to keep the setting at an overbias of 1.2 V
- SiPMs assignment for new boards
- Shaun Krueger has been working on algorithms to assign SiPMs to wedge boards, including the required jumper settings.
- Ben St.Laurent has been analyzing the data that Bobby took
- Mechanical assembly (Jim)
- James Wagner has completed all the component drawings, but they are not yet completely checked or signed off. They should be ready next week
- Assembly drawings have not been done and we still need to decide how many are needed. A least the top-level drawing is required.
- Temperature compensation (Jack)
- Electronic boards (Chris)
- All boards and supplies are in
- The populated Wedge board have been received and a testing is planned for next week
- The 86k 0.1% resistors have been received. These will be substituted onto the boards.
- The spare board will be updated to match the mini-Bcal boards including new gains for fADC and TDC outputs
- A direct comparison of the new pre-production boards and the spare board will be done, before any further optimization.
- Light guide gluing setup
- Tent for gluing has been completed and is in the ESB
- New gluing fixture parts are in. Jim will give Scot the parts for assembly and checkout