ANALYSIS OF ISOTOPIC CO2 MIXTURES BY LASER PHOTOACOUSTIC-SPECTROSCOPY

Photoacoustic spectroscopic studies on a mixture of six CO2 isotopes ( (CO2)-C-12-O-16, (CO2)-C-12-O-18, (CO2)-C-13-O-16, (CO2)-C-13-O-18, (O CO)-O-16-C-12-O-18, and (OCO)-O-16-C-13-O-18) in the wavelength range of 9-11 mu m by use of a home-built high-pressure continuously tunable CO2 laser with a bandwidth of 0.017 cm(-1) are discussed. CO2 isotope s present in the mixture could be determined with good accuracy. Furth ermore, the previously unknown absorption cross sections of some impor tant lines of the (CO2)-C-12-O-18, (CO2)-C-13-O-18, and (OCO)-O-16-C-1 3-O-18 isotopes in the 9-11-mu m range are reported. (C) 1997 Optical Society of America.