Mar 1, 2011 SiPM Electrical and Cooling
From GlueXWiki
Action Items from previous meetings
- Determine if swapped bias pins was accidental or in design (Chris)
-
Make low voltage cables for the SiPM test (Chris) -
Acquire material to absorb water for the box (Carl) -
Order dew point sensor (Jim)
Tentative Agenda
- Announcements
- Action Items
- Schedule, reporting, and manpower (Elton)
- SiPM production testing (everyone)
- Mechanical assembly (Scot)
- Mechanical (Jim)
- Mechanical drawings (Chuck)
- Temperature compensation (Jack)
- Preamp-summing (Chris is out but sent these notes)
Minutes
Attending: Jack, Carl, Jim, Chris, Chuck, Scot, Eugene, Nick, Yi, Elton.
- Announcements
- Action Items
- Schedule, reporting, and manpower (Elton)
- SiPM production testing (everyone)
- Optical
- Optical calibration complete and in log book
- Suggestion to keep one SiPM array for reference between measurement sets
- Static dissipation equipment installed
- micro-switches ready to install to interlock HV
- Testing preparations
- Checking all channels
- Nine V792 QDC modules. One mod has a single bad channel
- Cables are ok
- 3 out of 4 boards are fine. One has some dead channels.
- Connector to QDC boards miss connections, but seem to be ok on the bench. Investigating
- Different locations give different gains by 20-30%. Appear to have baseline oscillations which may be causing the problem. Will ask Fernando to take a look.
- Once the channels are checked, a full check of gain and light uniformity using SiPMs will be performed.
- Optical
- Mechanical assembly (Scot)
- All light guides have been measured for dimensional uniformity and look good.
- Have 11 J guides and 9 K guides. Have informed USM of the count.
- Gluing setup will require adding set screws to keep pressure on light guide while gluing. For the mini-Bcal will glue one guide at a time.
- Mechanical (Jim)
- Mechanical drawings (Chuck)
- Brackets have been designed for the mini-Bcal mount and they are in the machine shop for quotes.
- Clarification comment on light guide drawings have been added and drawings re-released.
- Temperature compensation (Jack)
- Spread sheet has been sent out with list of proposed voltage settings.
- Does not yet include the 80 FA + 120 last guides. They will be added soon.
- Patent disclosure has been requested so we are holding off on making detailed design and calculations available to external collaborators.
- Preamp-summing (Chris)
- Wedge board is complete with connectors and ready to be tested
- U-boards have come in. They will be assembled as time permits
- Fischer connectors are expensive and have long lead times. We will substitute them with trim trio connectors.
- Wrapping (Elton)
- Presented measurements of light transmission for no wrapping, tedlar, acid-free paper and Al mylar. No significant difference was seen.
- Tedlar was chosen for the wrapping material. Tedlar is the thinnest option. There is a concern that paper may absorb water over time and Al mylar is partially transparent.