Computation of electron impact K-shell ionization cross sections of Al, Ti, Cu and Mo atoms

The total cross sections of electron impact single K-shell ionization of atomic targets Al, Ti, Cu and Mo, with a wide range of atomic numbers from 11 to 42, are evaluated in the energy range up to about 1 MeV employing the relativistic correction method ,Which incorporates the ionic and relativistic effects. The experimental cross sections for all targets are reproduced satisfactoryily in the considered energies. Bethe K-shell-ionization cross sections are in good agreement with the experimental data and other theoretical data at high energies. The relativistic effect is found to be significant in Mo targets.