On electron impact ionization cross-sections and rates for multiply charged ions

The electron impact ionization cross-sections σ and rates $$\langle v\sigma\rangle$$ for multiply charged ions are calculated using the Coulomb–Born approximation with exchange (CBE). Values of σ and $$\langle v\sigma\rangle$$ are fitted by two parameter formulae and the corresponding parameters are presented for ionization of outer and inner shell electrons for ions belonging to isoelectronic series from H to Ca. A comparison of the present results with experimental data and other theoretical calculations is given.