Single and double ionisation of He by HCI — a recoil ion momentum study

Abstract

Single and double ionisation of He by highly charged ions have given rise to a huge amount of experimental as well as theoretical studies. The advent of the new generation of recoil ion spectrometers, which begin to provide experimental results in the field of ion-atom collisions, allow us to obtain a new insight into the ionisation mechanisms. We report for the first time angular and energy differential cross sections for the production of He recoil ions. These results were obtained in the intermediate energy range using a 6.7 MeV/u Xe 44+ projectile beam and a high resolution (better than 0.1 a.u.) recoil ion momentum spectrometer. They show strong differences in the momentum distributions of the recoil ions corresponding to the single and double ionisation processes.