Translational Energy Distribution of Electrons and Positive Ions in the Plasma of Microwave and High-Frequency Discharges of He, Ne, and Ar

Abstract

The mean electron energy, mean positive‐ion energy, and sheath potentials in the plasma of microwave discharges were measured by extracting the positive ions and electrons through a small hole in a metal probe and subjecting the effused particles to a retarding electric field. The electron and positive‐ion translational energy distribution fitted the Maxwellian distribution function The mean electron energy was independent of the input power to the cavity and position of visible plasma sampled along the axis of the discharge tube The electric field in the sheath in front of the probe orifice was mapped and approximate values of the sheath thickness are given. The variations of the sheath potential and electron density with pressure and power input and sheath potential profiles along the axis of the discharge tube are given.