Target dependence of slow electrons emitted in swift ion-atom collisions

Low-energy electron emission is studied for 3.6-MeV/u Au⁵³⁺ impact on Ne and Ar using the first-Born and continuum-distorted-wave eikonal-initial-state (CDW-EIS) approximations. By using optimized effective potentials to represent the target atom, very good agreement is obtained between the CDW-EIS results and experiments. The comparison with the calculations using the first-Born approximation shows that the emission is very asymmetric, with a preferential emission into the forward direction. A detailed study of the emission from each initial orbital of the target atom reveals features in the spectra which can be related to the structure of the initial-state bound wave function.