Doublet Structure of the L_2,3 Absorption Edge Singularity of Na Metal

Abstract

The singularity of the L_2,3 X-ray absorption edge of light metals possesses a doublet structure owing to the spin-orbit splitting of the core p level. The observed intensity ratio of the doublet is deviated from the expected 2:1. The deviation can be explained by introducing the electron-hole exchange scattering. A line shape formula is obtained which takes account of the exchange and spin-orbit interactions. It is used to analyse the Na spectra with success.