A note on charge recombination in low density polyethylene under a moderate ac 50 Hz field

Low density polyethylene 500 mu m thick samples have been submitted to a 15 MV m(-1) rms ac 50 Hz field. No charge accumulation in the samples has been observed after a few hours of polarization. This has been attributed to the recombination of the majority of electrons and holes alternately injected each half cycle. To confirm this assumption, a space charge has been injected in the sample by using a de electrical stress. Coupled measurements of space charge and electroluminescence have been made under a single and a double alternation ac 50 Hz field. Results have shown that the decrease of the installed charge at the interfaces is partially due to the recombination with injected carriers.