Compact TEA CO<SUB>2</SUB> Laser for a FIR Laser Photo-Excitation

Abstract

A TEA CO2 laser pumped FIR laser system for the collective scattering measurement of ion temperature has to be compact to be acceptable as a diagonostic tool. In order to develop a compact TEA CO2 laser, a volumetric photo-preionization by v.u.v. radiation was systematically studied using two types of spark source, a free spark and a surface-gap spark. The photo-electron production was determined almost entirely by a partial pressure of CO2. The surface spark was more efficient than the free spark, due to HLαline enhanced by the evaporated epoxy resin. By using these results, the glow-arc region in TEA discharge is discussed.