From: Geoffrey J. Gettelfinger
Sent: Friday, September 30, 2005 3:03 PM
To: Michael C. Zarnstorff; James H. Chrzanowski; Wayne T. Reiersen;
Bradley E. Nelson
Cc: Allen J. Patterson
Subject: LN2/Fabric/Material Tests

Some pieces of common industrial materials were immersed in LN2 to see how they behave.

1.  Woven Kevlar tape: Remained fully flexible, unfortunately not a vapor barrier in its uncoated form

2. Woven Kevlar, Nomex, and fiberglass composite cloth:  Same as 1, remained fully flexible, unfortunately not a vapor barrier in its uncoated form

3.  Polypropylene woven webbing:  Became hard and stiff during immersion but remained tough and did not break

4.  Silicone-coated fiberglass cloth:  Became hard and stiff during immersion but remained tough and did not break.  This product IS a vapor barrier and when used in thin sheets will likely perform well.  This product seems quite similar to the St. Gobain product used by C-Mod.

5.  Mylar (polyester) sheet:  No surprise here, it did just fine.

6.  Kapton (polyimide) sheet:  A mild surprise to the uninformed (me) the Kapton stayed nicely flexible.

A materials anecdote quite tangential from the above effort  comes from the recent testing of the TRC.
Red-colored GP-03 grade polyester/glass angle and channel was used for pedestrian brackets and raceways in the coil cryostat and was found to work quite well.  That said, the CTE may be exciting (badly).

Geoff