Abstract: The processes of vibration-rotation energy transfer between highly vibrationally excited KH (V=14-21) and CO2 have been studied by using the pump-probe technique. KH is formed by the K (5P)+H2 reaction. The pulse laser prepares KH in the highly vibrational levels. Energy gain into CO2 resulting from collisions with excited KH was probed by using laser overtone spectroscopy technique. The rotational temperatures of CO2 (0000, J=32-48) states were obtained. The average rotational energy of the scattered CO2 molecules is increased by a factor of 2.33 when KH level V=14 increases to V=21. The nascent distributions of recoil velocities for collisions were determined from stimulated absorption line profiles of individual CO2 rotational states. The average translational energy of the scattered CO2 molecules is increased roughly linearly as a function of CO2 J state. Under single collision conditions, state-specific energy transfer rate coefficients for collisions of highly excited KH with CO2 were obtained. For V=19, the integrated rate coefficients kint increases by a factor of 4.5 to V=14.

Key words: laser spectroscopy, V—R energy transfer, vibrational and translational energy, KH-CO2