Absolute cross section measurements for dissociative capture of H2+ in Ar

Absolute differential and total cross sections for dissociative capture of H2+ 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 cm2 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 H0 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 H2+ interacting with the target and with the two electron capture to form the excited state H2−.