FLUORESCENCE-SPECTRA AND KINETICS OF CS2

The fluorescence spectra of the A 1Σu + -X1Σg+ and a 3πu-X 1Σg+ transitions in Cs2 have been measured as a function of temperature and Xe buffer gas density. The observed spectra were normalized to the Cs atomic emission. The Xe density dependence of the normalized fluorescence was used to determine an average formation rate constant for the A 1Σ state of 4.2X 10-30 cm6/sec. Using a value of 1O-29 cm 6/sec for the a 3π formation rate constant, predissociation and quenching rate constants from the a 3π to the x 3Σ were determined to be 2.5X109 sec-1 and 9.8x10-10 cm6/sec. Also, the net collisional transfer rate constant from the A 1Σ to a3π was 1.5X 1O-11 cm3/sec. The fluorescence spectra were also used to predict the Cs atomic excited state fraction needed to produce an inversion on the A-X transition. The experimentally inferred value was 11% compared with a theoretical prediction of 0.25%. This result, coupled with the large loss rates, indicate that Cs2 is not an attractive laser candidate on the A-X transition. © 1979 American Institute of Physics.