In the search for universal features of electrical breakdown in solids, liquids and gases
E. O. Forster · 1982
Ever since Edison developed the use of electric energy as a means to do work, man has looked for ways to isolate the two wires required to convey electricity to the place of usage. Materials capable of isolating these wires by preventing electron transport between them were referred to as dielectrics. They include solids, liquids and gases. Extensive studies have been carried out over the decades to find the best, the most effective and the cheapest insulation system. As the voltage level increased with time so did the need for more efficient insulation. Because of the apparent physical differences, researchers tended to specialize in one of the three areas of materials and there has been little exchange among the three branches. Several attempts to provide cross fertilization among them met with very limited success. The present paper represents one such attempt in the area of electrical breakdown, one of the most crucial aspects of electrical insulation. The problem of electrical breakdown in gases has been studied in great detail over a much longer. time span than that in either liquids or solids.(1)This is not surprising since breakdown in gases leads to formation of a plasma and plasma physics is a very popular research subject. In looking for common features of this phenomenon in the three states of matter it is, therefore, convenient to use the wealth of knowledge generated in the area of gases as a starting point. This is the approach taken in the present paper. First several breakdown features obviously common to the three forms of matter are reviewed. This is followed by an examination of the factors controlling the transformation of gases into liquids and solids. Finally a unifying mechanism leading to electrical breakdown will be proposed and its validity examined in the light of available experimental evidence.