A NOVEL MEASUREMENT METHOD FOR X-RAY SPECTROMETERS WITH POSITION-SENSITIVE DETECTORS TO ENHANCE THE ENERGY RESOLU- TION

Crystalline materials are widely utilized in X-ray optics. Their use is based on the constructive interference of X-rays from atoms arranged in a periodic lattice. The diffraction condition, approximated with the Bragg’s law n = 2dsin B, connects together diffraction angle B, wavelength and separationd of the diffracting crystal planes. Due to this property, crystals have found their way to be used to monochromatize and focus X-rays. Both of the aforementioned functions are combined in the X-ray crystal spectrometers, where the radiation scattered by the studied sample is collected, monochromatized and focused to the detector by specifically designed crystal mirrors called analyzers. In order to increase the collected intensity, curved crystals are often used. The downside of the curving process is that it induces additional stresses inside the crystal, which degrade the energy resolution of the crystal analyzer. The stresses can be relieved by making cuts along the analyzer surface, but this also leads to the loss of collected intensity in terms of decreased analyzer surface.[1] As we have shown in [2], the resolution curve of a spherically bent analyzer can be explained with an additional angular compression that causes a shift in the local resolution curve. In this poster, we describe a novel measurement method[3] for X-ray crystal spectrometers using a position-sensitive (2D) detector, and demonstrate how it can be used to compensate the angular compression-related degradation of the energy resolution of a spherical crystal analyzer.