Observation and numerical calculations of space charge behaviour in gamma-irradiated low density polyethylene

摘要

When polymers are used for electrical insulation in space or at nuclear power plants, radiation-induced space charges or surface charges may give rise to an unexpected surface discharge or breakdown. The charge generation and accumulation process can be understood by examining the distribution of space charge inside the polymers irradiated by low-dose radioactive rays. In a previous report, the residual space charge distribution in γ-irradiated low density polyethylene (LDPE) was examined using the pulsed electroacoustic (PEA) method [1]. In this report, the space charge behavior inside a γ-irradiated LDPE is analyzed by a computer simulation technique. The simulation was performed based on the hopping model, assuming the mechanism which was expected from the previous experimental results. The simulation results are compared with the measurement results.