The total cross sections of electron-impact single-$K$-shell ionization of 14 atomic targets ranging from H to U $(1⩽Z⩽92)$ are calculated using a modified version of the BELI formula [Bell et al., J. Phys. Chem. Ref. Data 12, 891 (1983)] by incorporating both ionic and relativistic corrections in it. The proposed modified Bell model with a single set of parameters is found to provide an excellent description of the experimental data in the reduced energy range $1⩽E∕I_K⩽{10}^6$ ($E$ and $I_K$ are, respectively, the incident energy and ionization potential) with a performance level at least as good as any of the existing methods and models.

• Received 25 August 2005

DOI:https://doi.org/10.1103/PhysRevA.73.012708