A large-solid-angle X-ray Raman scattering spectrometer at ID20 of the European Synchrotron Radiation Facility.

An end-station for X-ray Raman scattering spectroscopy at beamline ID20 of the European Synchrotron Radiation Facility is described. This end-station is dedicated to the study of shallow core electronic excitations using non-resonant inelastic X-ray scattering. The spectrometer has 72 spherically bent analyzer crystals arranged in six modular groups of 12 analyzer crystals each for a combined maximum flexibility and large solid angle of detection. Each of the six analyzer modules houses one pixelated area detector allowing for X-ray Raman scattering based imaging and efficient separation of the desired signal from the sample and spurious scattering from the often used complicated sample environments. This new end-station provides an unprecedented instrument for X-ray Raman scattering, which is a spectroscopic tool of great interest for the study of low-energy X-ray absorption spectra in materials under in situ conditions, such as in operando batteries and fuel cells, in situ catalytic reactions, and extreme pressure and temperature conditions.