EFFECTS ON THE THERMALLY STIMULATED DISCHARGE-CURRENT SPECTRA OF A CURED EPOXY RESIN SYSTEM EXPOSED TO UP TO 2 MGy OF GAMMA AND NEUTRON RADIATION

摘要

The effects of high radiation doses of both γ and neutron radiation on the thermally stimulated discharge spectra of an epoxy resin system have been investigated. The glass transition temperature was found to depend both on the dose level and the nature of the radiation. Thermal cleaning techniques have been applied to the measured TSDC spectra which were shown to be due to charge migration. Modelling of ion charge transport showed that resultant TSDC spectra behaved in a similar fashion to dipolar processes, allowing a similar analysis. As a result data pertaining to the relaxation process can be derived and from which it was shown that the same compensation law operated for both irradiated and pristine samples. This relationship between the activation entropy and activation enthalpy held for both thermally cleaned TSDC spectra and for spectra obtained at different polarisation voltages.