Multielectron x-ray photoexcitation observations in x-ray-absorption fine-structure background

Abstract

Multielectron excitations involving deep and shallow core levels have been identified for the first time in the x-ray-absorption fine-structure (XAFS) energy range for crystalline samples, RbBr and β-${\mathrm{PbO}}_2$. The XAFS oscillations have been fitted and subtracted from the experimental data using theoretical standards. The positions of steps in the extracted background are in excellent agreement with the Z+1 approximation. The ability to determine this structure has important implications for XAFS and multiexcitation studies.