Importance of the interference effect in atomic excitation and ionization accompanying inner-shell vacancy creation

A theoretical model for electron excitation and ionization of atoms following inner-shell ionization is presented. Both the sudden creation of an inner-shell vacancy and the Coulomb interaction between the ionized electron and atomic electrons are taken into account. The transition amplitude is written as the sum of the conventional shake process and the multipole transition due to the Coulomb interaction between electrons. The valence-shell excitation and ionization probabilities accompanying K-shell photoionization of Ne are calculated. It is found that the interference between the shake process and the Coulomb interaction enhances the probabilities at low energies.