Ionization cross section by electron impact of helium-like ions

Abstract

In this paper we present our calculation of the ionization cross section by electron impact of C V, N VI, and O VII. Using the Flexible Atomic Code (FAC), we obtain the cross sections for the ionization of these ions from the ground state 11S, and from the unstable states 21S and 23S. Our results are in good agreement with those based on the Coulomb–Born (CB) approximation and the available measurements.