Re: Plastic and radiation damage

[Scott Schwahn <schwahn@cebaf.gov>]

I resend an old summary about plastic embrittlement, which was a summary
of replies to a similar question I posed:

Texts of Interest:
- AIP's "Atomic, Molecular & Optical Physics Handbook"
- CERN Report 82-10 (Compilation of Radiation Damage Test Data  Part
III:
Materials used around high energy accelerators.)
-At SLAC we have an internal document CN-104 entitled "Radiation
Resistance
of some Plastics and Insulating Materials" which takes data from
radiation
damage studies done at CERN.  This document shows that PVC shows mild to
moderate damage at 10e7 rads and unusable at 10e8 rads.
- The most comprehensive compilation of radiation hard materials that I
know
about  is held in the CERN reports 79-08, 79-04,82-10 and 89-12
-  Engineering Compendium on Radiation Shielding.  There is a table that
states the radiation tolerance levels for most plastics.

Other comments:
- approximately 100,000 rads to 2" thick HDPE before embrittlement
- it looks like most non-elastomer polymers have a damage threshold of
about
10**6 Gray. Kapton is an order of magnitude better and Teflon 3 orders
worse.


-- 

Scott O. Schwahn, CHP
Thomas Jefferson National Accelerator Facility
Newport News, VA
schwahn@jlab.org