Electron capture and ionisation in C5+, N5+, O6++H collisions

Abstract

Electron capture and ionisation cross sections have been calculated for collisions of C5++H, N5++H and O6++H in the velocity range of 5*106 to 2*109 cm s-1. Ab initio potential energy curves along with their d/dR and Lx coupling matrix elements were calculated and employed in perturbed stationary-state calculations to obtain the electron capture cross sections in the 5*106 to 1.2*108 cm s-1 velocity range. These cross sections are large, 2*10-15 cm2, and display the importance of electron capture into excited levels of the multiply charged ion. Three-body classical-trajectory Monte Carlo calculations were employed to obtain the electron capture and ionisation cross sections in the 2.5*108 to 2*109 cm s-1 velocity range. The electron capture cross sections decrease rapidly in this regime while the ionisation cross sections rise to a maximum at about 6*108 cm s-1 before decreasing as E-1. Good agreement is realised between the calculated cross sections and available experimentally observed values.