Initial state dependence of low-energy electron emission in fast ion atom collisions

Single and multiple ionization of neon and argon atoms by 3.6 MeV/u Au53+ i mpact has been explored in kinematically complete experiments. Doubly diffe rential cross sections for low-energy electron emission have been obtained for a defined charge state of the recoiling target ion and the receding pro jectile. Observed target specific structures in the electron continuum are attributable to the nodal structure of the initial bound state momentum dis tribution. The experimental data are in excellent accord with continuum-dis torted-wave eikonal-initial-state single ionization calculations if multipl e ionization is considered appropriately.