Rotational and Vibrational Transitions in Molecular Collisions

Abstract

Recent progress in understanding collision processes involving rotational and vibrational excitation in collisions of atoms (ions) with molecules in terms of simple models is illustrated for two systems. Rotational excitation of N2 in collision with He at 27 meV can be explained by an optical model. A more quantitative agreement is achieved by cross sections calculated exactly for the model potential of Tang and Toennies. Vibrational excitation probabilities for resolved single mode excitation of CF4 in small angle 10 eV ion collisions follow a Poisson distribution indicating a breathing sphere forced oscillator behaviour