Inelastic collisions between excited alkali atoms and molecules. VII. Sensitized fluorescence and quenching in mixtures of rubidium with H₂, HD, D₂, N₂, CH₄, CD₄, C₂H₄, and C₂.H₆

Abstract

5 2 P 1/2 ↔ 5 2 P 3/2 mixing and 5 2 S 1/2 ← 5 2 P 1/2 , 2 P 3/2 quenching in rubidium, induced in collisions with ground state H 2 , HD, D 2 , N 2 , CH 4 , CD 4 , C 2 H 4 , and C 2 H 6 molecules, have been investigated using methods of sensitized fluorescence. The rubidium vapor mixed with each of the gases was excited in turn by each component of the rubidium resonance doublet, and the resulting fluorescence, emitted at right angles to the direction of the exciting light, was resolved into the two fine-structure components whose intensity ratios were measured in relation to the gas pressure using photon counting techniques. The measurements yielded the following cross sections for the mixing and quenching collisions.For H 2 : Q 12 ( 2 P 1/2 → 2 P 3/2 ) = 11 Å 2 , Q 21 ( 2 P 1/2 ← 2 P 3/2 ) = 15 Å 2 , Q 10 ( 2 S 1/2 ← 2 P 1/2 ) = 6 Å 2 , Q 20 ( 2 S 1/2 ← 2 P 3/2 ) = 3 Å 2 .[Formula: see text]The mixing cross sections agree with theoretical values within an order of magnitude.