Considerations for conduction mechanisms under AC high field for low density polyethylene

Dissipation current waveform observation method, which has been developed by authors, is very powerful technique to detect high field nonlinear dielectric property and by using this method, not only the various kinds of numerical processing but also the observation on the various kinds of experimental condition by using arbitrary function generator are possible. In this paper, in order to discuss the charge injection and the space charge formation, the electrode´s metal dependences were examined from the results of FFT analysis, that is, the fundamental and third harmonics of dissipation current. Furthermore, in order to clarify the effect of cross-linking by-product, LDPE sheet with and without acetophenone is also examined. In this case, differential parts of dissipation current after the soaking the samples into the acetophenone were carefully estimated under various conditions. From the results of these experiments, it was confirmed that the effect of acetophenone will be varied with the presence of moisture.