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

The effects of high radiation doses of both gamma and neutron radiatio n on the thermally stimulated discharge spectra of an epoxy resin syst em have been investigated. The glass transition temperature was found to depend both on the dose level and the nature of the radiation. Ther mal cleaning techniques have been applied to the measured TSDC spectra which were shown to be due to charge migration. Modelling of ion char ge transport showed that resultant TSDC spectra behaved in a similar f ashion to dipolar processes, allowing a similar analysis. As a result data pertaining to the relaxation process can be derived and from whic h it was shown that the same compensation law operated for both irradi ated and pristine samples. This relationship between the activation en tropy and activation enthalpy held for both thermally cleaned TSDC spe ctra and for spectra obtained at different polarisation voltages.