9314377 Houston This two year award supports U.S.-France cooperative research in physical chemistry between Paul Houston, Cornell University, and Francois Rostas of the Paris Observatory in Meudon. The objective of their research is to develop a tunable vacuum ultraviolet (VUV) laser light source for the wavelength range 110-170 nm and its application to spectroscopy and dissociation dynamics of carbon dioxide (CO2). The laser is considered the light source of choice and necessity for investigating photo- dissociation of carbon dioxide (CO2) into carbon-oxygen and oxygen at low wavelengths. The U.S. investigator brings to this collaboration extensive expertise in molecular dynamics, especially in the area of photo-chemically laser dissociated molecules. This is complemented by the French investigator's expertise in VUV spectroscopy of diatomic and small polyatomic molecules of astrophysical importance. Carbon dioxide is an important atmospheric and interstellar constituent. In the earth's atmosphere, it has a profound effect on the thermal balance. It is also the principal constituent of the atmosphere of Mars and Venus. This project will advance our understanding of its optical properties and its photochemical processes. ***