High Energy Resolution X-ray Spectroscopy at SSRL and LCLS: Instruments and Applications

High-resolution hard x-ray spectroscopies (XES, HERFD, RIXS, XRS) are now well-established characterization tools for providing insights of material's electronic and geometric structure. The high brilliance synchrotron radiation beamlines have made feasible the routine study of the electronic structure and ligand environment of metal coordination compounds and active centers in metalloproteins, electrochemical process under in-situ conditions, as well as studies on catalytic systems under ambient conditions. Moreover, the recent availability of Linac Coherent Light Source (LCLS), provides some unique opportunities for the study of ultrafast electronic structure dynamics in various phenomena such as electron transfer processes, transient molecular states, molecular dissociation, etc. At SLAC National Accelerator Laboratory we have developed recently a set of high-resolution x-ray spectroscopic capabilities based on various multicrystal spectrometers. At SSRL we have built three multicrystal Johann spectrometers enabling XES/RIXS/HERDF techniques as well as X-ray Raman Spectroscopy. For LCLS, we have developed an energy dispersive multicrystal von Hamos spectrometer that records simultaneously the overall emission spectrum, enabling shot-by-shot time-resolved studies. Representative examples of application will be shown and discussed from the ongoing spectroscopy programs of SSRL and LCLS.