摘要
Lithium 1s photoelectron spectra are reported in high electron and photon energy resolution, with resolved LS term structure of the Li+ 1snl satellite transitions up to n=6. Branching ratios and anisotropy parameters of individual lines, determined over the 85–130 eV photon energy range, are compared with R-matrix calculations and with previous works. The high-angular-momentum satellite lines (L>~2) are found to contribute significantly to the 1snl satellite cross sections for n=3 and 4, and to become the dominant terms for n>~5. The high-angular-momentum lines exhibit the same photon-energy-dependence as the P-lines, providing experimental evidence that the continuum-continuum state coupling (equivalent to virtual electron collision processes) is responsible for the L>~1 terms in the satellite spectrum, in contrast to the electron relaxation (shake-up) mechanism responsible for the S-terms. The angular distribution of the lines in the Li+ 1snl, n=2–6 groups, determined at 110 eV photon energy, is in good agreement with calculations, showing more isotropic distributions for high-angular-momentum lines.