10min:
HIGH-RESOLUTION LASER SPECTROSCOPY OF THE A1 Sigma+ - X1 Sigma+ TRANSITION OF CaS.

TODD C. MELVILLE AND JOHN A. COXON, Department of Chemistry, Dalhousie University, Halifax, NS, Canada B3H 4J3.

High-resolution laser excitation spectroscopy has been employed for the first time to examine the A1 Sigma+ - X1 Sigma+ system of CaS. Gaseous CaS was produced in a Broida-type oven by the reaction of calcium metal vapor with OCS. A Coherent 699- 29 ring dye laser operating in single-frequency mode was used to investigate the rotational structure of the A - X transition. The present work extends the lower resolution work of Blues and Barrow on the same system to higher vibrational levels and has allowed the indentification of several level crossings that occur in the A1 Sigma+ state. The deperturbation analysis of the A - X transition will be discussed.