Fine-structure-changing collision cross sections within the low-lyingnD2states of rubidium induced by ground-state rubidium atoms

Abstract

The thermal cross sections for inelastic transfer of excited rubidium atoms from the $n^{2}D_{\frac{5}{2}}$ to the $n^{2}D_{\frac{3}{2}}$ fine-structure state caused by fine-structure-changing collisions with ground-state rubidium atoms have been measured by selective stepwise excitation of the rubidium atoms and observation of the resulting fluorescence. The cross sections (in units of ${10}^{\ensuremath{-}14}$ ${\mathrm{cm}}^{2}$) for $n$ being 5-9 are 2.9\ifmmode\pm\else\textpm\fi{}0.6, 6.9\ifmmode\pm\else\textpm\fi{}1.4, 11.5\ifmmode\pm\else\textpm\fi{}2.3, 17.1\ifmmode\pm\else\textpm\fi{}3.0, and 26.0\ifmmode\pm\else\textpm\fi{}5.0, respectively. The fine-structure-changing cross sections are of the order of the geometrical cross sections and increase slightly less than ${({n}^{*})}^{4}$ for the low-lying $n^{2}D$ states studied.