Resonance structure and absolute cross sections in near-threshold electron-impact excitation of the 4s2 1S-->4s4p 3P intercombination transition in Kr6+

Abstract

First measurements of absolute total cross sections for electron-impact excitation of an intercombination transition to a nonradiating state of an ion are reported. The cross sections for near-threshold excitation of the 4${\mathit{s}}^{2}$ $^{1}$S\ensuremath{\rightarrow}4s4p $^{3}$P transition of ${\mathrm{Kr}}^{6+}$ are dominated by dielectronic resonances. The measurements can serve as a benchmark for theoretical predictions of dielectronic resonance structure in the excitation of multicharged ions.