Resonant Vacuum-Ultraviolet Photoelectron Spectra of Aligned Li Atoms

A new method is described in which Li atoms are excited and aligned by pumping of the Li $1s^{2}2s{}_{}{}^2{}_{}{}^{}S_{\frac{1}{2}}^{}{}_{}{}^{}\to 1s^{2}2p{}_{}{}^2{}_{}{}^{}P_{\frac{1}{2},\frac{3}{2}}^{}{}_{}{}^{}$ transitions with a linearly polarized dye-laser beam, and subsequently raised to core-excited $1snl{n}^{\prime }{l}^{\prime }{}_{}{}^2{}_{}{}^{}S$, ${}_{}{}^2{}_{}{}^{}P$, ${}_{}{}^2{}_{}{}^{}D$ states by linearly polarized synchrotron radiation. The intensity of the electrons ejected upon the Li $1snl{n}^{\prime }{l}^{\prime }{}_{}{}^2{}_{}{}^{}S$, ${}_{}{}^2{}_{}{}^{}D\to 1s^2{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}\epsilon l$ autoionization strongly varied with the character of the core-excited state, the intermediate ${}_{}{}^2{}_{}{}^{}P_{\frac{1}{2}}^{}{}_{}{}^{}$ or ${}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ state, and the angle between the polarization vectors of the two photon beams.