[Halld-tracking-hw] FDC Prototype Gas leak discussion

[Tim Whitlatch]

Hi All,

Here are my notes from the discussion of the gas leaks in the FDC full 
scale prototype.

1. Causes and potential fixes for the production  packages were discussed
2. Some known and Possible causes of leaks include leaks through the 
rohacel bonding boudaries, deflection of unsupported wireplane pc board 
under o-ring, grounding vias on pc board, bond voids on cathode 
sandwich, protrusion of traces (3-4 mils) on pc board, not enough 
compression on o-ring, too much compression on rohacel, not enough 
stifnness in outer channel supports.
 
Action items

a. Develop test plan for testing existing design, slightly changed 
design and addition of G10 ring to support bolts and gas seal (Bill Crahen)
b. Get worst case additional material to Simon for background analysis 
(Bill Crahen)
c. Perform background analysis on increased material (Indiana U?)
d. Gather all changes needed for production pc board (Kim Shinault).

Cheers,

       Tim