The effect of X-ray radiation on conductivity of PP film

The authors deal with the delayed effect of X-ray-induced conduction in polypropylene (PP) film. The results show that resistivity, ρ, of the sample decreased with increasing dose rate and recovered gradually to the original value during a period of storage. The ρ of samples exposed to different dose rates had similar recovery rates in storage. If the sample was irradiated for a long time with a larger dose rate, ρ did not recovery completely. A TSC (thermally stimulated current) test showed that it was possible that some defects were formed in this situation. To explain the experimental results, the excitation and recombination theory of electron-hole pairs is used, assuming an energy-level model for the PP material. The theoretical conclusion agrees substantially with experimental data