SPACE-CHARGE PHENOMENA IN POLYETHYLENE AT HIGH ELECTRIC-FIELDS

The paper presents results of experiments undertaken to elucidate the behaviour of polyethylene under the influence of high electric fields. Especially when using virgin samples, some ‘anomalies ’ occur that are a result of a slow transition of the polymer to a preloaded state. It is shown that if two sets of traps are assumed, not only the thermodynamic equilibrium occupation but also the dynamic capture and escape processes must be taken into consideration for the deep ones and anomalies found experimentally under the influence of high electric field strengths in the region of more than 30 kV mm-1can be explained. A numerical simulation program leads to qualitatively correct results. © 1990 IOP Publishing Ltd.