Space charge distribution measured with short period interval up to electrical breakdown in polyethylene

The paper describes the space charge behavior measured with short period interval up to electrical breakdown in polyethylene film. Positive space charge was formed from the anode near the opposite electrode within 1.2 seconds after voltage application of 30 kV in a HDPE film. Up to electrical breakdown, this positive space charge formulation did not change. From this result, it is considered that there is the possibility that electrical breakdown in HDPE film is caused by hetero space charge, which enhances the cathode field just before electrical breakdown. The amount of homo space charge accumulation near both electrodes increased with time of voltage application in the LDPE film. Space charge distribution was remarkably changed with time. Electrical breakdown occurred when the negative space charge layer reached the cathode after hetero space charge was formed in the bulk. There is a possibility that hetero space charge formation may be a pre-breakdown phenomena in LDPE films.