Fine-structure effects on resonant transfer excitation cross sections for Li-like-ion collisions withH2and He

We have calculated configuration-mixing LS-coupling and intermediate-coupling cross sections for the process of resonant transfer excitation followed by x-ray stabilization in collisions of the Li-like ions ${\mathrm{S}}^{13+}$, ${\mathrm{Ca}}^{17+}$, ${\mathrm{Ti}}^{19+}$, ${\mathrm{V}}^{20+}$, ${\mathrm{Ni}}^{25+}$, and ${\mathrm{Ge}}^{29+}$ with ${\mathrm{H}}_2$ and He. Fine-structure interactions preferentially enhance the KLL peak (by up to 35% for ${\mathrm{S}}^{13+}$) over the KLn (n>L) peak (+5%), and this largely resolves the discrepancy that exists between theoretical LS-coupling calculations and experiment over the relative height of the two peaks for the case of ${\mathrm{Ca}}^{17+}$+${\mathrm{H}}_2$.