Theoretical state-selective and total cross sections for electron capture from helium atoms by fully stripped ions

Abstract

The four-body boundary-corrected first Born (CB1-4B) approximation is used to compute cross sections for single electron capture from helium targets by fully stripped ions. The projectile ions are H+, He2+, Li3+, Be4+, B5+, C6+, N7+, O8+, and F9+. An extensive list of theoretical state-to-state cross sections in these collisions at energies ranging from 20 to 10 000 keV/amu is given. This list includes the state-selective cross sections Qnlm for each individual triple of the usual quantum numbers {n,l,m} of the final hydrogen-like states alongside Qnl and Qn for the pertinent sub-shells and shells where the respective summations over m and {l,m} have been carried out. The maximal value of the principal quantum number n was chosen to vary from 4 (H+) to 10 (F9+) so as to satisfy the condition n≥ZP, where ZP is the nuclear charge of the projectile. Usually, the largest cross sections stem from those values of n that match the projectile charge (n=ZP). The total cross sections for capture summed over all the quantum numbers {n,l,m} are also tabulated. The overall goal of this study is to fill in lacunae in the existing databases of charge exchange cross sections that are needed in several inter-disciplinary fields. For example, in particle transport physics, which is of utmost importance in such emerging branches as hadron therapy, these cross sections constitute a part of the multifaceted input data for stochastic simulations of energy losses of multiply charged ions in matter, including tissue. Other significant uses of the present data are anticipated in charge exchange diagnostics within thermonuclear research project as well as in applications covering the relevant parts of plasma physics and astrophysics.