<title>Transverse radio-frequency-excited He-metal-vapor ion lasers</title>

Abstract

The transverse radio-frequency discharge, the features of which resemble those of the hollow-cathode discharge plasma, is very efficient and suitable for excitation of the ionic transitions in the He-metal vapour mixtures. This is due to the relatively high number ofthe high-energy electrons capable ofexciting the atoms and ions to the energetically high-lying states. The other advantages of the transverse radio-frequency discharge are: longitudinal homogeneity of the discharge, efficient transforming of the input power into the energy of fast electrons, simplicity of the discharge tube design, absence of the arc formation at higher input powers, and external electrodes enabling to operate with the substances of high chemical activity. The He-metal vapour ion lasers excited by the transverse radio-frequency discharge exhibit also some negative features: discharge tube overheating due to the high input power and deterioration of the inner walls of the discharge tube by the ion bombardment.