Space charges in ethylene-styrene copolymers irradiated by low-dose gamma rays

Space charges in ethylene-styrene copolymers irradiated by low dose gamma -rays were studied from the results of DC conduction, thermal pulse current, thermally stimulated current and residual voltage measurements. The number of carriers induced by gamma -rays and escaping from recombination becomes smaller with an increase in styrene content. The reason for this is thought to be that styrene absorbs the energy of electrons and increases the average energy necessary for ionization. The relationship between gamma -induced space charges and the morphological state of styrene is also studied in three kinds of polymers (random and graft copolymers and polymer blend). It can be said that styrene must be dispersed uniformly and bonded with ethylene in order to fully utilize the electron energy absorption effect of a benzene ring.