Microwave Breakdown of a Gas in a Cylindrical Cavity of Arbitrary Length

Abstract

It is possible to consider breakdown in a cylindrical microwave cavity whose radius is large compared to its length as approaching the conditions of parallel plate breakdown. This assumption has been used to measure high frequency ionization coefficients. The present paper investigates the corrections to be made when the length is increased. Numerical results are given for cavities whose ratios of radius to length are as low as 0.5, and the method is applicable to any cylindrical cavity. The breakdown data in these longer cavities are used to extend the high frequency ionization coefficient curves for air by a factor of ten.