Electron capture, ionisation and transfer-ionisation in fast Auq++He collisions

Cross sections for single electron capture and ionisation, as well as for simultaneous capture and ionisation ('transfer ionisation') are calculated for collisions of partially stripped Au q+ (q=6-25) ions with He atoms at collision energies between 20 and 300 keV amu -1 by using the classical-trajectory Monte Carlo method. The helium ion core has been represented by an effective charge Z eff (He)=1.69, while the electron interaction with the projectile ion has been described by a variable-charge potential. The calculated capture cross sections are in close agreement with the available experimental data, while the ionisation cross sections are consistent with them except for 10<or=q