A simulation for packet formation in XLPE films

Periodic packet formation in an oxidized cross-linked polyethylene (XLPE) was discussed through a computer simulation, where negative space-charge packet is assumed to be due to deficiency in mobile holes. Under high field, a positive carrier (hole) is generated from the acceptor (impurity) site to a hopping site and trapped there once. It is detrapped by hopping or recombines with the parent ion. At the same time, the acceptor is negatively ionized and behaves as an immobile negative charge. The packet-like behavior was reproduced by introducing extra coefficient of diffusion term. The mechanisms of carrier generation and problems of computer simulation were discussed.