Calculated electron impact K-shell ionization cross sections for atoms

A simple-to-use empirical model for the calculation of electron impact single K-shell ionization total cross sections for 60 atomic targets from H to U (1 ≤ Z ≤ 92) and the energies from threshold to ultra-relativistic range is described. Simplified BELL formula [K.L Bell, H.B. Gilbody, J.G. Hughes, A.E. Kingston, F.J. Smith, J. Phys. Chem. Ref. Data 12 (1983) 891] is used in the proposed model by incorporating in it both the ionic and relativistic corrections. The predicted K-shell ionization cross sections are compared with recently measured experimental data. Better agreement is found for all atoms considered except Xe. Moreover, the calculated results are also compared with other theoretical methods and empirical formulae. The predicted results achieve a level of agreement with both experimental data those are better than the predictions from the existing theoretical methods and empirical models. With the inherent simplicity of its structure, this model may be a prudent selection for the users where fast generation of electron impact single K-shell ionization total cross sections are required.