H. Klar et al., CALCULATION OF IONIZATION WITH AN ERROR ESTIMATE, Journal of physics. B, Atomic molecular and optical physics, 26(20), 1993, pp. 711-716
In a three-body model for ionization of an atom by electron impact we
present a formulation that has two terms. One is an approximation. The
other is a correction to the approximation whose form shows how it ca
n be minimized by appropriate choices of initial and final state vecto
rs. The approximation is compared with experiment and the correction t
erm is approximated and discussed.