The authors present results of a simulation of dielectric breakdown in three dimensions and analyze the fractal character of the resulting patterns. Simulations are done for integer values of eta between one and four with the breakdown probability of a bond being proportional to the electric field across the bond raised to the power eta . They find that the Hausdorff dimensionality of the patterns are about 2.5, 2.1, 1.9, and 1.75, respectively, for eta =1, 2, 3, and 4. They compare their results with fractal characters of patterns formed by simulation of diffusion-limited aggregation of particles.
 

Physical Review B, 33 5093-5, 1986.