PREFERENTIAL EXCITATION TRANSFER IN CSSTAR(6D3/2)-CS(6S1/2) COLLISIONS

A cw dye laser beam, tuned near the Cs 8761 Å resonance (Cs*(6P 1 2) → Cs*(6D 3 2) transition) is focused into a Cs vapor. At a Cs density higher than 5 × 1015 cm-3, we observe a greater 6P 1 2 population when the laser is on resonance than when it is off resonance. However, at a lower Cs density, the reverse is observed. This phenomenon is explained as due to the preferential excitation transfer process: Cs*(6D 3 2) + Cs(6S 1 2) → Cs*(6P) + Cs*(6P), and the corresponding cross secti on is estimated to be (1.5+1.5-0.7) × 10-14 cm2 by fitting the experimental results to an approximate rate-equation analysis. © 1978.