RESEARCH OF THE EFFECTS ON A NUCLEAR CABLE MATERIAL IRRADIATED BY BETA/GAMMA IRRADIATION

摘要

In this paper, irradiated samples by different irradiation doses of the beta/gamma radiation from a selected nuclear cable material, which were studied by tensile machine, DSC and DMTA. The research results show that the elongation at break (EAB) drops with absorbed dose of beta/gamma radiation and at the same dose the EAB drop for beta-irradiated samples is higher than that for gamma-irradiated samples, which means that this material becomes more brittler with more irradiation. The OITP value for the irradiated samples exhibits pronounced drop with absorbed beta/gamma irradiation dose. And moreover, the OITP value of these gamma irradiated samples drops faster than that of those beta irradiated samples. DMTA researches show that the storage modulus (E′) and the loss factor (tanδ = E″/E′, E″represents the loss modulus) of the irradiated samples present higher values with the increase dose of beta /gamma radiation. It is interest that the E′ behaves firstly an increase, then decreases by rising the temperature within the temperature range of -30-20 °C , and this trend becomes pronounced with increase of irradiation dose, combined with the activation energy, correspond to the glass transition process, for all the irradiated samples which hints that the glass transition process may be hindered in terms of a higher activation energy, but the movement unit could be smaller with a lower Tg, as a result of the beta/gamma irradiation.