Rainbow effect and dissociative processes in Na⁺-N₂, Na⁺-CO and Na⁺-CO₂ collisions

Dissociative processes in Na⁺-N₂, Na⁺-CO, and Na⁺-CO₂ collisions have been studied by measuring the time-of-flight spectra of the fragment atoms originating from dissociation. The peak positions of the fragment atoms N, C and O are in good agreement with those given by the spectator model and classical trajectory calculations. The atom peaks measured at small scattering angles ( theta approximately=10 degrees ) have an asymmetric form. The experimental results at small laboratory (lab) angles can be related to the rotational rainbow effect at large centre-of-mass angles. At large lab angles ( theta approximately=40 degrees ), on the other hand, both rotational and vibrational dissociation contribute almost equally to the spectra and the atom peaks show a nearly symmetric form.