Uwe Bergmann, Stanford Linear Accelerator Center
High-resolution energy analysis of the photon-out channel is a powerful advancement to hard x-ray spectroscopy experiments. For applications in the 6-10 keV range instruments with a resolution of 0.3 – 1 eV and a large solid angle are now available at several synchrotron facilities. The techniques performed at such instruments include non-resonant x-ray Raman scattering (XRS), resonant inelastic x-ray scattering (RIXS), x-ray emission spectroscopy (XES) and selective x-ray absorption spectroscopy (S-XAS). All of these techniques are bulk probes of the local electronic and geometric structure and provide unique information that is complimentary to that of traditional x-ray absorption spectroscopy. At SSRL beam line 6-2 we are now operating a multi-crystal analyzer setup in combination with either a Si (111) monochromator (~1 eV resolution) or a Si (311) monochromator (~0.2 eV resolution). Examples of the latest results will be presented in this talk. They include a) new high-resolution XRS studies of the oxygen K edge of liquid water under various conditions and their impact on structural models, b) the first XES studies of ligand to metal transitions in the oxygen evolving complex of photosystem II, and c) the application of 1s3p RIXS as a core hole clock in the ~ 0.1 – 1 femtosecond range. An outlook of how these techniques can be used in future pump-probe experiments at X-ray free electron lasers will conclude the presentation.
