Broadening of the Rb resonance lines by the noble gases

Abstract

Normalized emission spectra of the optically excited Rb resonance lines (7800 Å, 7948 Å) have been measured in the presence of He, Ne, Ar, Kr, and Xe for about 50 Å on either side of the lines. The perturber gas pressures were in the range 100-1100 Torr and the temperature was 318 °K. The spectra, normalized to the total emission, are shown to be due to binary collisions. Shifts and widths of the Lorentzian cores of the lines were obtained, at pressures sufficiently low for impact theory to apply. The widths are corrected for the Rb hfs and the instrument function. Various power-law fits to the near-wing intensities are presented and compared to theoretical expectations. The red satellites reported by other authors are found to be, in the low-pressure limit, mere shoulders on the line wing for Ar and Kr, while Xe barely produces an actual peak. The measured linewidths and shifts are compared to previous measurements.