Rubidium 5'P fine-structure transitions induced by collisions with potassium and caesium atoms

Abstract. A diode-laser fluorescence experiment was performed in order to study fine-StNCtUre transitions between 5'P states of rubidium atoms colliding with ground-state potassium or caesium atoms. The Rb(5'P,/,) state was optically excited and the intensity ratio of sensitized to direct fluorescence was measured. The obtained cross sections for the excitation energy transfer Rb('P,,J + Rb('PII2) induced by collisions with K and Cs ( T = 573 K) are u=54A2*30 % and U = 15 A2*30%, respectively. Assuming detailed balancing, the cross sections for the reverse process Rb('P,/,)+ Rb('P,,J are U = 60 Ai+30%, and U = 16.5 A2*30 % for K and Cs, respectively. 1