Developing M4, M5 edge HERFD-XANES and RIXS to investigate uranium biogeochemical processes

The proposed experiment will investigate the electronic structure of Uranium (U) in a wide range of environmentally relevant species as solid and adsorbed species using U M4, M5 edge high energy-resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) and resonant inelastic X-ray scattering (RIXS). U(VI), (V) and (IV) samples will be synthesised with a range of environmentally relevant ligands e.g. oxide, silicate and phosphate. The HERFD-XANES and RIXS spectra will be collected and analysed to determine how these techniques and approaches can be applied to determine U speciation in complex environmental systems. The results from HERFD-XANES and RIXS measurements will be supported by ligand field theory calculations to deepen our understanding of variations in the electronic structure of U in environmentally relevant samples.