Vibrational deactivation of N-2 by inelastic collisions with He-3 and He-4

Rate constant calculations for the vibrational deactivation of N-2(nu = 1) by helium atoms, employing the coupled-states approximation and the potential energy surface of Banks et al., are presented and compared with experiment in the temperature range 100-300 K. The low impact energy behaviour of the system is also investigated and compared with that observed previously for the CO-He system. The existence of resonances in the vibrational deactivation rate constants at low energies and their influence on low temperature rate constants are discussed. The implications of this work on the vibrational deactivation of N-2(nu = 1) by molecular hydrogen are discussed.