Correlation of Cs/foreign gas diffuse bands with theoretical interaction potentials

Fluorescence excitation is employed to survey diffuse spectral bands in mix tures of Cs with He, Ne, Ar, Kr, Xe, or N-2 over the wavelength range 430-4 70 nm. Direct fluorescence and sensitized fluorescence at low pressures are also utilized to associate various diffuse bands with their respective ato mic parent lines. The line-band associations, along with the positions and strengths of the bands, are then correlated with theoretical potentials for the collision pairs. The potentials exhibit a rich structure in the excite d state which qualitatively describes many of the diffuse band characterist ics and lead to the following conclusions: (1) red satellite bands are corr elated with long-range (20-30 a.u.) shallow potential wells in the excited state, (2) violet satellite bands are correlated with maxima in the excited state potentials in the range 10-20 a.u., and (3) detached bands are forme d near avoided crossings in the range 6-10 a.u. A diagnostic technique for foreign gas density is also demonstrated for N-2 and He. Published by Elsev ier Science Ltd.