Differential scattering of metastable neon on neon

Differential elastic scattering cross sections for a beam of metastable neon (Ne*) incident on ground-state Ne atoms have been measured in the centre-of-mass energy range 7-53 eV. Two peaks identified as rainbow maxima were observed at tau =E theta approximately=45 and 67 eV deg. Oscillatory structure identified as coherent scattering on a gerade-ungerade (g-u) pair of potential curves was also observed. Use of the calculated potentials of Cohen and Schneider (1974) and a semiclassical theory for g-u oscillations allows observed features in the cross section to be attributed to particular molecular states, but difficulties due to complicated interference between scattering on the relevant potentials preclude any unique determination of improved potentials without supplementary information.