Observation and analysis of charge behavior in gamma-irradiated LDPE

Observation and analysis of charge behavior in gamma-irradiated low-density polyethylene (LDPE) is carried out. In our previous works [1], it is found that a large amount of electrons and parent positive ions, which was escaped from recombination, remained in LDPE irradiated by relatively low dose gamma-ray. When a de high voltage was applied to the gamma-irradiated LDPE, positive charges were observed near cathode and they spread towards the cathode. It is supposed that the observed positive charges are parent ions and it becomes observable when the electrons are swept out into the anode by de voltage application. In this report, a simple model of charge behavior is proposed which is based on the measurement results and the time dependence of charge behavior is numerically analyzed. Furthermore, the results of the analysis are compared with the measurement results.