Electron-Impact Ionization Cross Section of Ions

A comparative study has been made of the ionization cross section of ions ${\mathrm{Li}}^{+}$, ${\mathrm{Na}}^{+}$, ${\mathrm{K}}^{+}$, ${\mathrm{Rb}}^{+}$, ${\mathrm{Cs}}^{+}$, ${\mathrm{Ne}}^{+}$, ${\mathrm{N}}^{+}$, and ${\mathrm{Mg}}^{+}$ using different velocity distribution functions for the atomic electrons in classical impulse approximation. The results are discussed in the light of the available experimental and theoretical results.