State and species selective energy flow in gas ensembles containing vibrationally excited O2

Abstract

State-to-state, collision-induced, energy transfer is followed to equilibrium through sequences of collision cycles in gas ensembles containing vibrationally excited oxygen molecules (v = 8 and 1) in several different atomic and molecular bath gases. Quantum state distributions for each of the constituent species are available at each stage of the ensemble's evolution and enable the dominant energy exchange mechanisms to be identified. Equilibration is generally a complex process that evolves through several phases of inter- and intra-molecular events, each with their characteristic response rate to collisions. The results suggest that single quantum state population loss rate constants, however precisely determined, may miss key features of the overall equilibration process.