High-field conduction and space charge in polyethylene

We have investigated space-charge behaviors in polyethylene by using the laser-induced-pressure-pulse technique and discussed the space-charge effects on high-field phenomena, such as conduction and breakdown. The effects of space charge on conduction current have been reported in many papers, but they are not well understood yet. One of them is a transient current peak in polyethylene. This was observed by many researchers and was explained by the transient SCLC (space charge limited current) theory. But there has been no direct evidence for it so far. In this study, we measured conduction currents and space-charge profiles in cross-linked polyethylene (XLPE), and discussed the relationship between conduction current and space-charge