Valence photoelectron satellites of neon

Synchrotron radiation was directed at neon gas, creating ${\mathrm{Ne}}^{+}$ ions in ‘‘satellite’’ states characterized by the configurations 1$s^2$2$s^2$2$p^4$nl, in addition to the main-line final states: 2$s^{\mathrm{-}1}$ and 2$p^{\mathrm{-}1}$. Satellite features appearing in the photoelectron spectrum were studied in the near-threshold region with photon energies from 55.2 to 99.7 eV. For three of the satellite peaks, the angular-distribution-asymmetry parameter ${\beta }_i$ varies with kinetic energy in much the same way as the asymmetry parameter of the 2p line. None of the satellites have a ${\beta }_i$ like that of the 2s line. All the satellite partial cross sections ${\sigma }_i$ have a kinetic-energy dependence similar to the partial cross section of the 2p main line. However, the ${\sigma }_i$ curves are not identical, and some deviation from the 2p intensity behavior is observed. These ${\beta }_i$ and ${\sigma }_i$ results are used to confirm the previous assignments of the satellite final states in neon and to consider, in general, the energy-dependent behavior of satellites near threshold.