Electronic Relativistic Effects in Ion‐Atom Collisions

ABSTRACT The electronic relativistic effects on atomic inner‐shell ionization processes by low‐energy charged‐particle impact have been studied by the use of the binary‐encounter approximation. The velocity distribution of the target electron is taken into account. The momentum representations of the electron wave functions are obtained for nonrelativistic and relativistic atomic models by means of Fourier transformation. The inner‐shell ionization cross sections were calculated with the obtained momentum distributions. The electronic relativistic effects are explained due to the large high‐momentum component in the momentum distribution of the relativistic electron. The calculated total K‐shell ionization cross sections with the relativistic binary‐encounter approximation are compared with the nonrelativistic ones and the other theoretical model as well as the experimental data.