Theory of inelastic collisions between low-lying excited- and ground-state Ne atoms

A quantum-mechanical study of low-energy inelastic collisions of excited- and ground-state Ne atoms has been undertaken. Close-coupling calculations of cross sections for the transitions ${}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\to {}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$, ${}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}\to {}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}\to {}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$, and ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}\to {}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$ have been performed at collision energies below 3 eV. All cross sections exhibit a rapid falloff at low energies, reflecting barriers and repulsive walls present in the potential curves. Spin-orbit coupling is assumed to be the transition mechanism. Comparison with experimental data suggests that neglected rotational coupling might be important for some of the quite weak transitions at energies below about 0.1 eV.