ENERGY POOLING IN CESIUM VAPOR

We report an experimental study of energy pooling collisions involving Cs atoms in the 6P and 5D states. The 5D state was populated by a cw dye-laser tuned to the cesium dipole-forbidden transition 6S --> 5D at 685.0 nm. The 6P state was populated by subsequent radiative relaxati on of the 5D state. The 6P population density was determined from the absorption of a cw diode-laser probe beam. The population densities of the 5D state and the higher, by energy pooling excited states were de termined by measuring the corresponding fluorescence intensities relat ive to the fluorescence intensity from the optically thin quasi-static wings of the cesium D-2 line. The rate coefficient for the process Cs (6P) + Cs*(6P) --> Cs**(6D) + Cs(6S) is found to be (4.2 +/- 0.13) x 10(-10) cm(3) s(-1) at T = 570 K. In addition, estimates of the rate c oefficients for the processes Cs(6P) + Cs*(5D) --> Cs**(7D) + Cs(6S) and Cs(5D) + Cs*(5D) --> Cs**(7F) + Cs(6S) are given.