High resolution study of Q-branches in the E1Π-X1Σ+ (0,0) band of 12C16O, 13C16O, and 13C18O

A tunable and narrowband vacuum ultraviolet laser system near lambda = 107.5 run is used to record Doppler-free molecular beam spectra of the E(1)Pi-X(1)Sigma(+) (0, 0) band for three isotopomers of carbon monoxide. The Q branches of the E-X (0, 0) bands in (CO)-C-12-O-16, (CO)-C-13-O-16, and (CO)-C-13-O-18 are fully resolved in this study, performed at a resolution of 0.02 cm(-1) (FWHM). The newly obtained data are included in a comprehensive fitting routine with previous data to yield optimized molecular constants for the upper level. (C) 2004 Elsevier Inc. All rights reserved.