Vibrational relaxation and vibration-rotation energy transfer between highly vibrationally excited KH(X1Σ+, v=14-21) and CO2

The vibrational levels of KH(X1Σ+, v″=0-3) were generated in the reaction of K (5P) and H2. Vibrational state total relaxation rate coefficientskv″(CO2) for KH (v″=14-21) are measured in an overtone pump-probe configuration. The rate coefficient kv″(CO2) is strongly dependent on vibrational quantum number. Scattered CO2 (0000, 32≤J≤48) molecules were excited to CO2 (1005, J+1) states. The rotational temperatures of CO2 (0000, J=32-48) states populated by collisions with highly vibrationally excited KH (v″=14-21) are 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 average translational energy of the scattered CO2 molecules is increased roughly linearly as a function of CO2J state. Under single collision conditions, state-specific energy transfer rate coefficients for collisions of highly excited KH with CO2 are obtained. For v″=19, the integrated rate coefficients kint increases by a factor of 4.5 to v″=14.

► KH (v″=14-21) total relaxation rate coefficients by CO2 are measured accurately. ► The average rotational energy of scattered CO2 increases by a factor of 2.33 when v″=14 to v″=21. ► The average translational energy in scattered CO2 increases linearly as a function of J state. ► For v″=19, the integrated rate coefficients KH (v) increases by a factor of 4.5 to v″=14.