COLLISIONS BETWEEN BARE HE AND LI-LIKE IONS
M.Keim,A.Achenbach,T.Kirchner,H.J.Ludde and R.M. Dreizler
Institut fuer theoretische Physik, Robert Mayer Strasse 8, D-60054 
Frankfurt, Germany.
Inelastic scattering of bare He from Li-like ions is investigated for 
impact energies ranging from a few keV to 1 MeV. Unlike in collisions 
between protons an Li-like ions, electron capture by bare He ions is very 
sensitive to the particular target ion and does not obey scaling laws. We 
show that a proper inclusion of ionization is decisive for obtaining 
reliable capture data at intermediate impact energies. The strong 2s-2p 
excitation channel allows for a detailed investigation of screening 
effects due to the K-shell spectator electrons in the target ion.