Absolute absorption cross-section measurements of CO2 in the ultraviolet from 200 to 206 nm at 295 and 373 K

Laboratory measurements of the absolute absorption cross-section of CO2 at the temperatures 295 and 373 K have been made between 200 and 206 nm using cavity ring-down spectroscopy. Below 205 nm, the cross-section at 373 K is significantly larger than at 295 K, whereas beyond 205 nm measurements at both temperatures yield cross-sections approximately equal to the Rayleigh scattering cross-section, within experimental error. The present measurements should resolve a long-standing discrepancy between previously published data on this system.