The ${}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}:{}_{}{}^2{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}$ partial photoionization cross-section ratios have been measured for the rare gases in the ionization continuum and within resonance structure. The wavelength range for this study was from the ${}_{}{}^2{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}$ ionization threshold to 304 Å. The ratio of the cross sections was found to be constant over this wavelength range, yielding ratios of 1.54, 1.77, 1.93, and 2.18 for Xe, Kr, Ar, and Ne, respectively. Within resonances, the ratio changed dramatically. Results are illustrated for xenon.

• Received 14 May 1975

DOI:https://doi.org/10.1103/PhysRevA.12.1459