Electrical breakdown for uniform fields in compressed gases

Abstract

The electrical breakdown and prebreakdown characteristics of uniform fields in compressed gases are described. The failure of Paschen's law and the dependence of the breakdown voltage on the material, preparation and area of the electrodes, on the dust content of the gas, and on the type of applied voltage are included. The failure of the Townsend and streamer mechanisms of low-pressure breakdown is discussed, and a summary is made of the many suggested breakdown mechanisms for compressed gases. These are divided into three groups: breakdown due only to field emission of electrons, breakdown due to electron-field emission and space charge in the gas, and breakdown due to electron-field emission and charge collection on an electrode. The breakdown and prebreakdown characteristics are interpreted in terms of the various breakdown mechanisms, and the areas indicated where further investigations are needed. The surface flashover of insulating spacers in compressed gases is also briefly reviewed.