Polarity dependence of electrical breakdown in argon under a non-uniform electric field

Abstract

A considerable difference in the breakdown potential of a uniform pressure gas (specifically argon) under an asymmetric non-uniform electric field is observed depending on the polarity of the field. The degree of variation in the breakdown potential between the two polarities can be explained if one assumes a strong variation of the ion-induced secondary electron emission coefficient with the magnitude of the reduced electric field at the cathode. The magnitude of the breakdown potential can be predicted by evaluating the breakdown criterion along multiple field lines if one includes a numerical factor to account for diffusion of electrons out of the preferred breakdown channel.