COMPUTER-SIMULATION OF CHARGE DYNAMICS IN ELECTRON-IRRADIATED POLYMER FOILS

A computer simulation is described which allows the study of charge motion in thin polymer films of the type used for electret transducers. The simulation operates with a variety of possible boundary conditions and can include nonlinear transport terms as well as time-varying radiation-induced conductivity. Electron-irradiation parameters, including radiation-induced conductivity and electron deposition profiles, are computed using a single-scattering Monte Carlo model of the polymer. The time-dependent charge-transport equations are solved by direct discretization of the partial differential equations. Using a fast minicomputer, the charge-transport solutions run approximately in real time for realistic polymer parameters. Results are discussed for open- and short-circuit irradiation and for charge recall experiments.