Rad damage to teflon and PTFE

["Jeffrey A. Leavey (532-4595 / 5-3466)" <certhp@VNET.IBM.COM>]

I hope someone can help with a non-HP question:
What is the rad damage resistance of teflon and teflon-like
materials (ie. PTFE)??

We use PTFE insulators for electrical penetrations on our
accelerator and had one fail recently. It lead to a vacuum
leak which shutdown a beam line. Our theory is fluorine
was liberated from radiation which attacked the insulator.
We run a 700 MeV synchrotron with a 90 MeV LINAC injector.
I measured 7 rad (photon and fast neutron) over one month
(typical operating conditions) and the insulator was in place
for about 5 years. 35 rad total seems way too small to me.

Any info or ideas are welcome.

Thanks,
Jeff
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Jeffrey Leavey                          certhp@vnet.ibm.com
X-ray Lithography Program                         IBM Corp.
914-892-4595                       East Fishkill, NY  12533
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