Charge transfer of keV O+ ions with atomic oxygen

Abstract

We report absolute differential cross sections for charge transfer scattering of 0.5–5 keV O+(4S) ground state and O+(2D, 2P) metastable ions by atomic oxygen at angles between 0.04° and 3° in the laboratory frame. Absolute total charge transfer cross sections, derived from these measurements, are compared with previously published data. The measurements were made using a flowing gas target, which consisted of a mixture of atomic and molecular oxygen produced by passing O2 through a microwave discharge. The atomic oxygen cross sections were obtained by appropriate subtraction of the signal due to molecular oxygen from that due to the mixture of O and O2. These data are relevant to model calculations of energetic O+ precipitation into the upper atmosphere and to the diffusion of low‐energy O+ ions in the ionosphere.