Untersuchung des Nichtgleichgewichtszustandes an stationären Edelgasplasmen unter Normaldruck

Abstract

It is shown that in wall stabilized rare gas arcs under normal pressure deviations from Saha-equilibrium occur. These deviations are very strong for Helium and Neon, smaller for Argon and Krypton discharges and are caused by diffusion of neutral and charged particles.

A numerical method is described for the evaluation of temperature and density distributions from measured line intensities in the case of non-equilibrium, based on the balance equations of the arc plasma. Results are given for Neon, Argon and Krypton arcs of 0.15 and 0.3 cm radius. A simple validity condition for local thermal equilibrium in a plasma with diffusion effects is derived. The influence of non-equilibrium on the determination of transition probabilities is discussed.