COSTER-KRONIG YIELDS OF THE XE-54 L-SUBSHELLS MEASURED THROUGH SYNCHROTRON PHOTOIONIZATION

The method of selective photoionization of individual subshells by monochromatized synchrotron radiation has been employed to measure all Coster-Kronig yields of the Xe-54 L subshells. The energy of the primary radiation was set at about 50 energy points in the range of the L edges. At each setting, the induced Xe L fluorescence and the induced Ar K fluorescence (used for normalization purposes) were recorded simultaneously by a Si(Li) detector. Both Xe and Ar were in the gaseous state. The recorded fluorescence spectra were carefully analyzed with proper modeling of the line tailing due to the intrinsic line profile and the detector line shape. The Coster-Kronig yields were derived by fitting the measured fluorescence intensities versus primary energy with the photoelectric cross sections. The derived yields are sensitive to the precise dependence of the cross sections on primary energy. Evaluations have been performed assuming a smooth power-law dependence and employing corrections for electron-correlation effects, which were estimated from comparative calculations in the independent-particle approximation and linear-response approximation models. Still, the uncertainties of the correlation effects constitute the main contribution to the uncertainties of the derived Coster-Kronig yields. The finally adopted values are f(12)=0.12+/-0.03, f(13)=0.23+/-0.04, and f(23)=0.14+/-0.02.