Contribution of higher multipole terms of Coulomb interaction to ionization in low-energy heavy-ion collisions

The two-center Dirac equation is solved in spherical coordinates using the multipole decomposition of the electron-nucleus interaction. The total and differential ionization probabilities in collisions of a hydrogenlike ion with a bare nucleus are calculated for different impact parameters. The contribution of the higher multipole terms of the interaction to these probabilities is analyzed. The influence of relativistic effects is examined as well. (paper)