EXISTENCE OF THE BOTTLENECK IN VIBRATIONAL-RELAXATION OF DIATOMIC-MOLECULES

High-temperature vibrational relaxation of diatomic molecules is analy zed using master equation and Fokker-Planck diffusion equation modelin g. Both approaches me based on the nonperturbative forced harmonic osc illator vibrational energy transfer rate model. The results show that the effect of the retarded diffusion at the intermediate vibrational e nergies during the relaxation process (bottleneck), predicted in the p revious studies, does not exist at the high temperatures. It is also s hown that the interpretation of the high-temperature vibrational relax ation as a diffusion-type process is inadequate because of the strong effect of multiquantum energy transfer. The obtained results, applied to interpretation of the rates of thermal dissociation, suggest an imp ortant role of rotations in molecular activation at the high vibration al energies.