COLLISION PROCESSES OF ELECTRONS WITH MOLECULAR-HYDROGEN IONS

Collision processes of electrons with trapped ions of mass numbers 1, 2, 3, 5, 7, 10, 14 and 20 are investigated in the concentric electron-beam device. Trapping characteristics are measured and lead to the conclusion that all the ions in the trap are hydrogenic. Cross section functions for the electron impact dissociation of H2+, H3+ and H 5+ are measured. The shape of the H2 + dissociation indicates that the molecular ions are trapped for a sufficiently long time for vibrational decay to upsilon =0 to occur. There is good agreement between the present low energy H3+ dissociation data and previous work. Dissociation cross sections for H 5+ and the temperature dependence of the e-H 5+ recombination rate are measured. The latter is in good agreement with previous room temperature data and facilitates the prediction of the recombination rate in the Jovian atmosphere.