Role of Intrinsic Plasmons in Conduction-Band X-Ray Photoemission from Solids

I show that intrinsic plasmons are created in x-ray photoemission experiments on the conduction bands of simple metals. Unlike the core case, the plasmons are produced by many-body effects and are a direct consequence of electron correlation. A theory of the intrinsic plasmon production is given and a calculation of the electron energy-loss spectra in conduction-band x-ray photoemission from Mg and Na is presented. The calculation takes into account both intrinsic and extrinsic plasmon production and the agreement with experiment is good.