Resonant x-ray Raman scattering in BKα emission spectra of boron oxide (B2O3) excited by undulator radiation

The satellite structure for the B Kα emission spectrum of boron oxide has been elucidated by threshold experiments carried out by varying the excitation energy of the incident undulator beam from below the B K absorption edge to several tens of eV above the absorption edge. Priminent emission of the satellite peak was observed when the excitation energy was tuned to the narrow pre-edge peak in the absorption spectrum, corresponding to the transition from B (1s) to an unoccupied antibonding p${\mathrm{\pi }}^{\mathrm{*}}$ orbital. It is concluded that the satellite peak originates from resonant x-ray Raman scattering due to a B(1s)-p${\mathrm{\pi }}^{\mathrm{*}}$-B(1${\mathit{s}}^{\mathrm{-}1}$) transition.