High Frequency Gas Discharge Breakdown in Hydrogen

Abstract

Electrical breakdown of hydrogen at high frequencies has been treated theoretically on the basis of the Boltzmann transport equation. Inelastic collisions are taken into account as a loss term in the Boltzmann equation and measured values of the ionization efficiency are used in the integral determining the ionization rate. The energy distribution function for electrons may be expressed in terms of the confluent hypergeometric function and simple exponentials. The ionization rate and diffusion coefficient are calculated using these distribution functions and kinetic theory and are combined with the diffusion equation to predict breakdown electric fields. These predicted electric fields are compared with experimental values measured at 3000 mc/sec. They are also compared with older measurements by other workers at frequencies ranging from 3 mc/sec. to 100 mc/sec. The breakdown equation calculated from kinetic theory and using no gas discharge data other than the collision cross-section measurements and involving no adjustable constants predicts breakdown electric fields well within the limits of accuracy determined by these cross sections over a large range of pressure, container size and frequency of applied field.