Inelastic collisions between selectively excited rubidium6D2-state atoms and noble-gas atoms: Fine-structure-state mixing

Inelastic collisional processes in fine-structure-state mixing have been studied by selective stepwise excitation and observation of the resulting fluorescence during collisions of excited rubidium $6{}_{}{}^2{}_{}{}^{}D_{\frac{5}{2}}^{}{}_{}{}^{}$ state atoms with various noble-gas atoms. It is shown that for intermediately excited rubidium atoms the fine-structure-state mixing cross sections are generally increasing from helium to xexon. The cross sections for the process $\mathrm{Rb}\left(6\mathrm{}{}_{}{}^2{}_{}{}^{}D_{\frac{5}{2}}^{}{}_{}{}^{}\right)+A\left(n{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}\right)\to \mathrm{Rb}\left(6\mathrm{}{}_{}{}^2{}_{}{}^{}D_{\frac{3}{2}}^{}{}_{}{}^{}\right)+A\left(n{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}\right)+\Delta E$ have the values ${\sigma }_{\mathrm{fs}}^{*}=2.4\mathrm{}\pm 0.9, 3.1\pm 1.2, 2.6\pm 1.0, 5.8\pm 2.2, \mathrm{and} 9.3\pm 5.6$ in units of ${10}^{-14\mathrm{}}$ ${\mathrm{cm}}^2$, where $A$ denotes in sequence any one of the noble gas atoms He, Ne, Ar, Kr, and Xe, respectively. Transfer cross sections for the transfer of excited Rb$6{}_{}{}^2{}_{}{}^{}D$-state atoms out of the doublet were also determined and are about an order of magnitude smaller than the fine-structure-mixing cross sections.