Microwave Determinations of Average Electron Energies and the First Townsend Coefficient in Hydrogen

Abstract

A microwave method of measuring the average energy of electrons in a gas in the presence of a d.c. field has been developed through a measurement of the ratio between the electron diffusion and mobility. By solving for a.c. and d.c. distribution functions it is found possible to compare quantitatively the effective a.c. ionization coefficient and the first Townsend coefficient in hydrogen. It is then possible to calculate the first Townsend coefficient from a.c. breakdown data in hydrogen and these values are compared with previously determined values. Measurements of average energy have been made and values calculated from theory compared with previous measurements of average energy. All measurements are in substantial agreement with each other and with the theoretically determined values.