Determination of the average electron energy in the positive column of an He - Ne glow discharge

Measurements of the average electron energy in the positive column of an He - Ne glow discharge are reported. A Langmuir probe second-derivative method was used for discharge currents from 20 to 200 mA with a 4 cm radius tube and a gas pressure of 0·06 Torr. Electron energy distribution functions for He - Ne mixtures were determined and from these the average electron energies calculated. The experimental values obtained are shown to give reasonable agreement with a modified version of the Schottky theory.