SINGLE AND DOUBLE-IONIZATION OF HE BY HCI - A RECOIL ION MOMENTUM STUDY

Single and double ionisation of He by highly charged ions have given r ise to a huge amount of experimental as well as theoretical studies. T he advent of the new generation of recoil ion spectrometers, which beg in 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 sectio ns for the production of He recoil ions. These results were obtained i n the intermediate energy range using a 6.7 MeV/u Xe44+ projectile bea m and a high resolution (better than 0.1 a.u.) recoil ion momentum spe ctrometer. They show strong differences in the momentum distributions of the recoil ions corresponding to the single and double ionisation p rocesses.