Dynamics of energy transfer during charge-exchange in symmetric diatomic systems

The measured, efficient energy transfer between vibration and translation during charge exchange in N2+ on N2 collisions is compared with a model which exploits the near u-g character of the electronic-exchange interaction. The dynamics of the concurrent electronic and vibrational-exchange process taking place during collisions are considered. The measurements and analysis indicate that significant vibrational exchange can occur in concert with small center-of-mass deflections, and changes of an even number of vibrational quanta are strongly favored at center-of-mass angles (<1°) and velocities about 3×106 cm/s (∼0.013 a.u). The dominant vibrational transitions are induced by the nonspherical component of the charge distribution of the N2 molecule at potential curve crossings for which the electron-exchange frequency is a multiple of the vibrational frequency.