K-shell ionization cross sections of light atoms due to electron impact

Electron impact ionization cross sections (EIICS) of K-shell have been evaluated for light atoms (C, N, O) at incident energies ranging from ionization threshold to 1 GeV. The plane wave Born approximation is used in the proposed model by incorporating it in exchange, coulomb and relativistic effects along with the contributions of transverse inter- action to ionization cross sections. In present model, we require two constants for each atom, ionization energy (I) and the electron occupation number (N). Adequate compar- isons have been made with other theoretical methods, empirical formulae. The predicted EIICS of K-shell also compared with experimental data. Obtained results are in good agree- ments with available experimental data.