Correlation in fast collisions of highly charged ions with atoms

Atomic hydrogen and helium ionization by impact of 3.6 MeV/u Au53+ is investigated within classical trajectory Monte Carlo and quantum-mechanical continuum distorted wave models. For helium ionization, a description of initial and final electron states in terms of Hartree-Fock potentials is compared with hydrogenic models. Different ionization mechanisms are characterized. A strong correlation of the electron, projectile and target nucleus is observed. Good agreement is obtained between calculations performed with the different models