EXPERIMENTAL-STUDY OF CESIUM 6P(J)-]7P(J')+6S ENERGY POOLING COLLISIONS AND MODELING OF THE EXCITED ATOM DENSITY IN THE PRESENCE OF OPTICAL-PUMPING AND RADIATION TRAPPING(6P(J))

An experimental study of caesium energy pooling collisions, Cs(6P(J)) + Cs(6P(J)) --> Cs(7P(J')) + Cs(6S(1/2)), at thermal energies, has bee n carried out in a capillary cell using diode laser excitation. Use of the capillary cell minimizes the effects of radiation trapping, but n onetheless, such effects still play a significant role in the analysis . Consequently, a rate equation model, which treats simultaneous effec ts of saturation, optical pumping, and radiation trapping, has been de veloped and is used to determine the Cs(6P(J)) atom density under thes e experimental conditions. The excited atom densities are combined wit h measured fluorescence ratios to determine rate coefficients for the caesium energy pooling process. Our values for these rate coefficients are in agreement, within combined error bars, with values we have rec ently obtained under very different experimental conditions.