Theoretical study of differential charge-transfer cross sections for Ne4++He collisions at low energies.

Abstract

A quantal two-channel calculation is applied to study charge-transfer differential cross sections in ${\mathrm{Ne}}^{4+}$ on He collisions at laboratory impact energies from 220 to 500 eV. The experimental data of Tunnell et al. were used to fit empirical potential curves and coupling terms from which the observed oscillatory structures in the differential cross sections were analyzed. In contrast with the double-charge-transfer process in ${\mathrm{C}}^{4+}$ on He, where the oscillations in the differential cross sections are attributed to pure Stueckelberg oscillations, we demonstrated that the differential cross sections for charge transfer in ${\mathrm{Ne}}^{4+}$ on He exhibit many fine fast oscillations and the observed structures are due to the envelopes of these unresolved fast oscillations. Classical deflection functions are used to help in interpreting the calculated oscillations.