Absolute cross section measurements for dissociative capture of H 2+ in Ar

Abstract

Absolute differential and total cross sections for dissociative capture of H 2 + in Ar to produce H −, at projectile energies between 1.0 and 5.0 keV and for scattering angles from −4° to 4° were measured. The absolute total cross sections (TCS) for the dissociative capture to produce H − are of the order of magnitude of 10 −17 cm 2 and our measurements appear to merge well with previous experimental results. The measured TCS are one order of magnitude lower than the dissociative capture for the formation of H 0 atoms. The angular distributions of the H − fragment show a monotonic decrease in the differential cross sections with increasing angle and several interesting structures are observed, which give information on the production of H −, i.e., attributed to the predissociative states of H 2 + interacting with the target and with the two electron capture to form the excited state H 2 −.