Journal Article Research Support, U.S. Gov't, Non-P.H.S. X-ray optics RIXS dynamical theory resonant inelastic X-ray scattering 7440-57-5 Bragg diffraction Gold Research Support, Non-U.S. Gov't X-ray collimation X-ray energy calibration X-ray refractive lenses analyzer asymmetric monochromator beam position monitoring broadband transmission of metallic gratings cavity-based X-ray free-electron lasers diamond crystals freely tunable polarization conversion high heat load high resolution high-resolution monochromators inclined double-crystal monochromator inelastic X-ray multilayer mirror multiple-beam diffraction non-coplanar diffraction non-traditional crystal materials polarization rotator of terahertz waves