Progress in the Development of New Optics for Very High Resolution Inelastic X-Ray Scattering Spectroscopy

We report on the progress in the development of new optics for very high resolution inelastic x-ray scattering spectroscopy. The principle of monochromatization and spectral analysis exploits the effect of angular dispersion in asymmetric Bragg diffraction in backscattering. It has a potential of monochromatizing medium-energy x-rays (5-10 keV) to meV and sub-meV bandwidths. We observe the effect of angular dispersion and study the performance of a CDW monochromator for 9.1 keV x-rays, based on this principle. The monochromator consists of three crystals playing the role of a collimator (C), a dispersing element (D), and a wavelength selector (W). Two CDW monochromators, with the second one functioning as an analyzer, are used to measure the effect of monochromatization. An energy bandwidth of 2.2 meV for a single monochromator is demonstrated.