Effect of electrical aging on space charge distribution in polyethylene

The dependence of the space charge distribution of a polyethylene sample on injecting time or aging time is studied using the pulsed electroacoustic method. In non-aged samples, the space charges, originated from homo-polar electrode injection, distribute in the vicinity of the electrode interface. It is shown that charge injecting time affects the peak height and width of the space charge distribution curve. In aged samples the amount of space charges increase significantly, and their distribution peaks with positive and negative polarities appear alternatively, which gets more apparent with aging time