DETERMINATION OF FINE STRUCTURE TRANSITION CROSS SECTIONS OF Rb(7^(2)D) ATOMS INDUCED BY COLLISIONS WITH MOLECULES OF H_(2) OR CO

The cross sections for fine-structure transition(FST)of Rb(7^(2)D)atoms induced by collision with molecules of and CO have been experimentally determined by the method of selective stepwise excitation of Rb atoms and observation of the resulting fluorescence.The cross sections(in units of 10^(-14)cm^(2))for Rb(7^(2)D)·H_(2) are σ_(fs)(7^(2)D_(5/2)→7^(2)D_(3/2))=0.16±0.03,σfs=(7^(2)D3/2→7^(2)D_(5/2))=0.24±0.05,for Rb(7^(2)D)-CO:σfs=0.10±0.06 and σfs=0.15±0.09.The cross sections for transfer out of the 7^(2)D doublet were also determined.