Inner-shell Photodetachment from Li$^{-}$ and C$^{-}$

Photodetachment from the K-shell of Li$^{-}$ and C$^{-}$ has been investigated using the merged ion-photon beam technique on the Advanced Light Source Beamline 10.0.1. Photoexcitation and detachment of 1$s$ electrons leaves the neutral atoms in core-excited states that subsequently Auger decay to produce positive ions which are detected as a function of photon energy. Recent experiments yield higher resolution spectroscopy than our previous studies [1,2] and provide new measurements of the absolute cross sections for double detachment. Several resonances are investigated for Li$^{-}$ in the photon energy range 57-66 eV, while the spectrum for C$^{-}$ shows one prominent resonance near 281.8 eV. Comparisons of the cross sections, the character of observed resonances, and the effects of post-collision interactions will be discussed. [1] N. Berrah \textit{et al.}, Phys. Rev. Lett. \textbf{87}, 253002 (2001); [2] N.D. Gibson \textit{et al.}, Phys. Rev. A \textbf{67}, 030703 (2003).