Platinum-catalysed recombination of CO and O2in sealed CO2TEA laser gases

Abstract

Measurements have been made of the rates at which a hot platinum wire catalyses the recombination of CO and O2 at small partial pressures in a basic gas mixture containing CO2, N2 and He at atmospheric pressure (about 105 Pa). The results are applied to the development of a long-lived, sealed, UV-pre-ionisation CO2 TEA laser operating with high CO2 concentrations, in which the recombination of CO2 dissociation products is essential. The volumetric 'pumping speeds' for O2 and CO are shown to increase rapidly with the temperature of the platinum wire but to be independent of both the reaction time and the partial pressures of O2, CO and CO2, within a given range. The presence of water vapour, up to 21/2%, does not reduce the rate of recombination of CO and O2.