Vibrationally Inelastic Scattering of High- n Rydberg H Atoms from N2 and O2

The vibrationally inelastic scattering of Rydberg H atoms \(n = 30-50\) from N ₂ and O ₂ at E_coll = 1.84 eV was studied as a function of laboratory deflection angle. On average, 4 times more vibrational excitation was observed in collisions with O ₂ than with N ₂. Vibrational excitation of O ₂ results largely from collisions in which an electron is briefly transferred from O ₂ to the proton core, while the Rydberg electron remains a spectator. This provides further evidence that the free electron model applies to low energy collisions involving the ionic core leading to substantial momentum transfer.