Inelastic scattering of NO(²Π) with atomic and molecular colliders. Rotational and fine-structure excitations

The inelastic collisions of NO (T_rot ≤ 5 K) with Ar, Xe, CO, N₂, O₂, N₂O and CO₂ were studied in molecular beams at center-of-mass collision energies 750-2500 cm^-1. Rotational, Λ-doublet and spin-orbit distributions of scattered NO(²Π _{1 2 3 2}) were determined. In all the scattering experiments (with the possible exception of Ar) no preferences wer observed in the Λ-doublet populations. The rotational distributions all appear Boltzmann-like, with somewhat different rotational temperatures. The populations of the ²Π _{1 2} and ²Π _{3 2} spin-orbit states depend on the nature of the collider, but do not show any clear relationship with the extent of rotational excitation. No evidence of long-range attractive interactions is revealed in any of the systems studied.