April 12, 2011 SiPM Electrical and Cooling
From GlueXWiki
Action Items from previous meetings
- Determine if swapped bias pins was accidental or in design (Chris)
- Develop front and back views of jumper sheets. Also get latest version of drawings (Jack)
- Request Hamamatsu data sheets from Chile to be used as input to jumper settings for boards (Elton)
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Double-check that the jumper settings for #37 (U-board counting) are correct (Jack) -
Provide section views of board to Fernando (Jim) -
Run temperature configuration for cooling plate with new geometry (Jim) -
When design is complete, order 2 mechanical assemblies with latest geometry (Jim)In progress as design is finalized -
Populate SiPM wedge board to be used for checking electrical issues (Fernando and Chris)
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)
Minutes
Attending: Fernando, Eugene, Elton, Jim, Nick, Andrei, Tim, Jack
- Announcements
- Action Items
- Schedule, reporting, and manpower (Elton)
- SiPM production testing (everyone)
- Software updated to latest changes
- Cable for temperature sensor (borrowed for mini-Bcal) has been replaced
- Chiller is being refilled with liquid
- Bobby, Tom and Elton will meet with Yi to learn how to operate the system
- Mechanical assembly (Scot)
- Mechanical (Jim)
- Showed latest thermal FEA calculations
- Model has ss standoffs and plastic washer to isolate the cooling plate from the spreader board
- The connections to the 4-wire RTD needs to be finalized including connections through the top plate. Could possibly use the connector used for power
- Currently the model shows a variation of 0.8 deg C across the cooling plate. Changing the standoffs to plastic reduces the gradient from 0.8 to o.6 deg C.
- Two watts of heat is conducted from the spreader plate down to the cooling plate
- The cooling plate dissipates 12 W, 10 W is convective heat load
- Maximum temperature on the spreader plate is about 50 deg C.
- It will be useful to study the temperature gradients on the mini-Bcal readout after removing from Hall B.
- Mechanical drawings (Chuck)
- Temperature compensation (Jack)
- Difficulty finding higher precision resistors.
- Final optimization will occur once the operating point is determined for the SiPMs (from beamtest)
- Fernando: may also wish to revisit the standing current in the chain
- Preamp-summing (Fernando)
- Ringing on boards has been found (first in the EEL and also in the beam test data)
- Did not previously look for it on the bench
- Third wedge is almost assembled and will be used to diagnose the ringing problem.
- Data from the beam test with one bias on at a time is being studied for clues to the problem.
- PS is now under new software control in F117