Fractal character of DC trees in polymethylmethacrylate

The fractal dimensions of DC trees in polymethylmethacrylate have been investigated using the self-correlation function. The fractal-established range is proportional to the tree length for both positive and negative polarities of the applied voltage. For positive polarity, the fractal dimension increases with increasing inception voltage and saturates at 1.5 to 1.6. For negative polarity, the fractal dimension is nearly constant, approximately=1.5, as a function of voltage.<
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