Abstract
High energy electrons play an important role in triggering the damage process in polymeric dielectrics, causing ageing or initiating avalanche breakdown. In order to investigate the transport properties of these high energy electrons, first paraffin is used as the model material for polyethylene, and the interfacial photoemission technique, the method to inject electrons into it. The results are compared with those measured using polyethylene sample. The mean free path of the photoelectrons deduced from the energy distribution curves was found to be in the order necessary for electron multiplication, thus indicating the possibility of the occurrence of avalanche breakdown. The possible energy loss process of the high energy electrons injected into hydrocarbons is also discussed.