Transmission of neutron and γ-irradiated fused quartz, crystalline quartz, teflon, polyethylene and TPX at mm- and sub-mm wavelengths

The transmission of fused and crystalline quartz, teflon, polyethylene and TPX was measured at mm- and sub-mm-wavelengths after neutron and γ-irradiation of the samples at doses comparable with typical values for vessel windows in ignited fusion experiments. Whereas fused and crystalline quartz and — with some restriction —teflon and polyethylene retained their transparency even after such extreme exposures, the transmission of TPX was degraded by irradiation doses one or two orders of magnitude below those expected for such experimental conditions.