A Study of the Vibrational Excitation of H₂ by Measurements of the Drift Velocity of Electrons in H₂−Ne Mixtures

Abstract

Measurements of electron drift velocities have been made in 1·160% and 2·892% hydrogen-neon mixtures at 294 K and values of EI N from 0·12 to 1·7 Td. The measurements are highly sensitive to the region of the threshold of the v = 0 → 1 vibrational excitation cross section for hydrogen and have enabled more definitive tests of proposed cross sections to be made than was possible using drift velocity data for H₂−He and H₂−Ar mixtures. The theoretical v = 0 → 1 vibrational excitation cross section of Morrison et al. (1987) is shown to be incompatible with the present measurements. A new set of hydrogen cross sections has been derived from the available electron swarm measurements in pure hydrogen and hydrogen mixtures.