Reponse of Rubber Insulation Materials to Monoenergetic Electron Irradiations.

摘要

The electron charge disposition in ethylene-propylene rubber (EPR) insulation specimens irradiated with monoenergetic electrons has been investigated. Studied was charge disposition in slab and cylindrical (cable) geometries. For each geometry, charge behavior was observed as a function of environment, electron energy, and surface termination. Under certain conditions charge was accumulated and spontaneous breakdown did occur during irradiation in the vacuum environment; however, no evidence of breakdown was observed during ambient air exposures. Based on these experiments, it is concluded that electron charge buildup and breakdown is not apt to occur in EPR rubber insulation exposed to electrons from a LOCA radiation environment provided that the insulation is in contact with an ionized medium. The results can probably be applied to other organics and it appears that the LOCA beta spectra need not be precisely duplicated insulation-radiation qualification tests.