Inner shell ionization produced by the Compton effect

The creation of inner-shell vacancies in atoms via the Compton effect is discussed. It is shown that the Klein-Nishina approximation leads to a simple vacancy distribution among the shells, independent of the photon energy. When atomic binding effects are taken into account an energy-dependent distribution can be calculated which tends to the Klein-Nishina results at higher photon energies. The inner-shell vacancies produce a potential energy on the ionized atom which is not necessarily small when compared with the recoil energy of the emitted electron. This additional effect contributes to a more complete description of mechanisms by which energy is transferred by the Compton interaction. Calculations are performed for aluminum exposed to photons with energies from 10 to 5100 keV