15min:

E. PLÖNJES, P. PALM, I. ADAMOVICH, J. W. RICH, Department of Mechanical Engineering, The Ohio State University, Columbus, OH 43210; W. URBAN, Institut für Angewandte Physik der Universität Bonn, 53115 Bonn, Germany.

Gaseous CO in an Ar diluent is prepared in vibrational state v=1 by absorption of pulsed CO laser radiation. Energy subsequently diffuses into higher vibrational states ( to v=40) by vibration-to-vibration exchange pumping. This diffusion of energy through vibrational quantum states is observed by step-scan FTIR emission spectroscopy on the 1^st overtone CO bands. The method permits monitoring of the time evolution of the vibrational state populations during the exchange pumping process. v=2 emission spectra at 1 cm^-1 resolution and 50 µsec time intervals are obtained. Vibrational state-resolved energy exchange rates are inferred from these measurements. In addition, state-resolved associative ionization rates for collisions of vibrationally excited CO are inferred.