Analysis of dielectric breakdown patterns in parallel-plate capacitors

The parallel-plate capacitor cells are used as model systems for studying t he dielectric breakdown (DB) patterns. Air, a liquid crystal and several ki nds of oils are used as the dielectric material sandwiched between the plat es. We study the types of patterns formed with different materials, voltage s and cell thickness. The fractal dimensions and the conditions for getting each type of DB pattern are obtained for the first time. In addition, the fractal dimensions of patterns simulated by using the active walker model ( AWM) are also analyzed and compared with the experimental DB patterns.