Optical threshold excitation functions of Xe 5s,5pphotoionization satellites near the 5s−1Cooper minimum

Excitation spectra of undispersed vuv and uv visible emissions from photoionized Xe 5s,5p satellites has been observed in the region between the 5${\mathit{s}}^{\mathrm{-}1}$ threshold and the 5${\mathit{s}}^{\mathrm{-}1}$ Cooper-minimum region. A vuv spectrum shows a number of resonance-enhanced satellites due to an interchannel coupling with doubly excited Rydberg states. Peculiar threshold enhancement in a uv spectrum around the ${\mathrm{Xe}}^{2+}$ ${}_{}{}^3{}_{}{}^{}$ ${\mathit{P}}_2$ limit is explained by an initial-ionic-state correlation and a post-threshold enhancement (shakedown) after the ${\mathrm{Xe}}^{2+}$ ${}_{}{}^3{}_{}{}^{}$ ${\mathit{P}}_0$ and ${}_{}{}^1{}_{}{}^{}$D limits by inelastic scattering.