Radiation ageing of polymers

Radiation effects on polymers in the presence of air are characterized by d ose rate effects and at enhanced temperature by synergistic effects of temp erature and radiation. For a reliable simulation of long-term ageing of pol ymers, conditions for the homogeneous radiooxidation have to be reached. Th e dose rate values, at which the homogeneous oxidation of irradiated EPR/EV A plates of various thicknesses occurs throughout the sample interior, have been determined. The methodology for the lifetime assessment of cable poly meric materials on the base of the oxidation induction time determination i s described.