Investigation of gas chemistry in the sealed TEA CO<inf>2</inf> laser

Abstract

A general view on the plasma chemistry of lasers, which primarily includes the changes of CO2, CO and O2 species, and the corresponding influence on the operation of the sealed transversely excited atmospheric (TEA) CO2 laser, utilizing a corona discharge preionized system, has been given. Decomposition process of CO2, especially in the case of standard CO2/N2/He gas mixture, was observed. The addition of H2 as well as CO/H2 gases extends the total number of stable discharge pulses in the system. Hydrogen improves the plasma stability and the output energy, while carbon monoxide significantly reduces decomposition of CO2. The CO2/N2/He(/CO/H2) has shown itself as the most convenient gas mixture of achieving long-life operation. An increase of CO2 concentration in this mixture, when the initial content of CO was 10% has been recorded. © 1994.