Lithium 1smain-line and satellite photoemission: Resonant and nonresonant behavior

Abstract

We present experimental results on core-level photoemission of atomic lithium, leading to both main-line and satellite states of the ${\mathrm{Li}}^{+}$ ion (1snl where n=2–5). We compare the measured 1s2s ${\mathrm{}}^1$,3S main-line cross sections with recent relaxed Hartree-Fock calculations and with previous experimental results, finding reasonable agreement in both cases. For the n=3 satellite, our results disagree with earlier photoemission work which was complicated by additional peaks at 52 eV kinetic energy. We discuss possible explanations for these extra peaks. For the doubly excited state 1s(3s3p) at 71.14 eV, we present total cross-section results in good agreement with previous photoabsorption measurements. The qualitative differences among our partial cross-section profiles are discussed, and the phase for the total cross section is rationalized by estimating the signs of pertinent matrix elements.