Beschreibung:
<jats:p>An unparalleled resolution is reported with an inelastic X-ray scattering instrument at the Cu<jats:italic>K</jats:italic>-edge. Based on a segmented concave analyzer, featuring single-crystal quartz (SiO<jats:sub>2</jats:sub>) pixels, the spectrometer delivers a resolution near 25 meV (FWHM) at 8981 eV. Besides the quartz analyzer, the performance of the spectrometer relies on a four-bounce Si(553) high-resolution monochromator and focusing Kirkpatrick–Baez optics. The measured resolution agrees with the ray-tracing simulation of an ideal spectrometer. The performance of the spectrometer is demonstrated by reproducing the phonon dispersion curve of a beryllium single-crystal.</jats:p>