Limitations on X-ray threshold fine structures imposed by the gross structures of emission spectra

Abstract

The X-ray emission spectra of free electron metals are calculated as functionals of the many body threshold exponents of Nozieres and deDominicis. The final state interactions are treated in a screened exciton approximation using a selfconsistent Hulthen screened electron-hole interaction determined from the threshold exponents alpha _l. For L_2,3 threshold exponents alpha ₀>or approximately=0.15, the emission is markedly non free electron like. Thus, for free electron metals, these calculations indicate that the exponents fall in the range 001or approximately=0.4, alpha ₁0=0.26, 0.18 and 0.15 for Na, Mg, and Al respectively. The implications of these results for the theory of X-ray excited states of metals are discussed.