Inelastic collisions between selectively excited rubidium atoms and ground-state rubidium atoms

Abstract

Inelastic-collision processes in fine-structure-changing collisions have been studied by selective stepwise excitation and observation of the resulting fluorescence. Hereby, the effect of ground-state rubidium atoms colliding with excited-state rubidium atoms was investigated. The ground-state density was changed by three orders of magnitude by performing the measurements over the temperature range of 75 to 200 /sup 0/C. The cross section for fine-structure-changing collisions (i.e., Rb(6/sup 2/D/sub 5/2/)+Rb(5/sup 2/S/sub 1/2/)..-->..Rb(6/sup 2/D/sub 3/2/) + Rb(5/sup 2/S/sub 1/2/)) is sigma/sub fs/ = (1.0 +- 0.6) x 10/sup -13/ cm/sup 2/. The cross sections for transfer out of the fine-structure doublet (i.e., Rb(6/sup 2/D)+Rb(5/sup 2/S/sub 1/2/)..-->.. states other than Rb(6/sup 2/D)) is sigma/sub tr/ = (3.8 +- 0.6) x 10/sup -13/ cm/sup 2/. It is demonstrated that for the intermediate excited rubidium states, both the fine-structure-changing and transfer cross sections are of the order of the geometrical cross section of the excited rubidium states.