Determination of Cs(np)-Xe interactions from spectral line profile measurements

The 6s-7p, 8p and 9p absorption transitions in caesium perturbed by xenon foreign gas at a temperature of approximately 500K and densities up to 1.2*1019 atoms/cm3 have been observed with a high-resolution computer-controlled spectrometer. A Fourier analysis technique to deconvolve the asymmetric line core from instrumental and Doppler effects yields width, shift and asymmetry for the 7p an 8p doublets independent of the instrument and directly comparable with line-broadening calculations. Normalised profiles of the wings of the 7p and 8p transitions, and of the entire 9p contour are also given from measurements at sufficiently high resolution that instrumental effects are negligible. The observed line core-parameters and line profiles are compared with Anderson-Talman lineshape calculations (1956). The authors also note the observation of multiple-perturber satellites as predicted by the Anderson-Talman theory based on the assumption of additivity of the interaction.