Measurements are presented for the blue-wing satellite bands of the Rb first resonance line (780 nm) emitted in the presence of the noble gases Ne, Ar, Kr, and Xe. The continuum intensity per spectral interval and perturber density is expressed as a fraction of the total Rb (780 nm) fluorescence from optically thin vapor. Over the ∼${10}^{18}$-${10}^{19}$ ${\mathrm{cm}}^3$ density range investigated this normalized satellite-peak intensity is found to scale linearly with perturber density and approximately exponentially in $\frac{-1\mathrm{}}{T},T$ being the absolute temperature. In the classically forbidden region beyond the satellite peak the intensity drops exponentially with frequency for Xe perturbers, but departs from exponential behavior in the Ar and Kr data. We observe undulations in the spectra between line center and the satellite. This is expected due to the possibility of interference between contributions to the transition probability at two internuclear separations, the separations at which the difference potential equals the photon energy.

• Received 29 April 1974

DOI:https://doi.org/10.1103/PhysRevA.10.1464