The fractal analysis of the treeing process

The purpose of this study is to analyze the growth mechanism of trees which generate from a pointed tip of a needle electrode inserted into insulating materials. The fractal dimension of the discharge luminescence pattern was determined from fractal theory. The fractal analysis of the treeing process was performed by correlating the fractal dimension to the tree growth length, the quantity of luminescence in the tree area, and the luminous length measured in each phase angle area. One cycle of applied voltage was divided into twenty equal areas, which were marked by /spl phi/1/spl sim//spl phi/20 in order from one negative peak to the next negative peak of applied ac voltage. A correlation between the tree growth length and the fractal dimension of the discharge luminescence pattern of the tree region in /spl phi/7 and /spl phi/17 was obtained.