Rotational and vibrational excitation in low-energy H+-H2scattering experiments

Abstract

Rotationally resolved measurements of vibrational excitation in H+-H2 scattering have been performed at ECM=10 eV. Differential cross sections and transition probabilities for various Delta v and Delta j processes as well as the average vibrational energy transfer are presented and compared with the DECENT model of Giese and Gentry (1974). The measured vibrational energy transfer is higher than in the calculations and does not peak at the rainbow angle, but shows a monotonic rise with scattering angle. The rotational transition probabilities for Delta j=2 and Delta j>2 processes are distinctly different, both in magnitude and in angular behaviour, in qualitative agreement with the properties of the potential surface. Rotational excitation is found to be more probable in connection with simultaneous vibrational excitation than for vibrationally elastic scattering.