Sensitized fluorescence in vapors of alkali metals. XI Energy transfer in potassium–rubidium collisions

Abstract

Sensitized fluorescence in rubidium vapor, induced by collisions with excited potassium atoms, was investigated to determine the total cross sections for inelastic collisions between excited potassium atoms and rubidium atoms in their ground states. The collision cross sections for the various excitation transfer processes are as follows: Q12′ (K42P1/2 → Rb52P3/2) = 40 Å2, Q22′ (K42P3/2 → Rb52P3/2) = 27 Å2, Q11′ (K42P1/2 → Rb52P1/2) = 2.7 Å2, and Q21′ (K42P3/2 → Rb52P1/2) = 1.9 Å2. The partial pressure of potassium vapor in the K–Rb mixture was kept largely below 10−5 mm Hg to eliminate effects due to the trapping of potassium resonance radiation.