Аннотация:The reionization mechanism of neutralized helium in low-energy ion-scattering spectroscopy is clarified on the basis of ab initio Hartree-Fock self-consistent-field calculations for fifteen diatomic systems. Reionization is explained by level crossings of the He 1s level with open valence levels of the target, which is caused by the antibonding interaction of the He 1s level with the target core levels. Calculated threshold energies for reionization are qualitatively in good agreement with those observed in the experiments.
