energies of inner shells of highly charged heavy ions requires an accurate spectroscopy in
the region of hard x-rays suitable at a limited source strength. For this purpose the focusing
compensated asymmetric Laue crystal optics has been developed and a twin-spectrometer
assembly has been built and commissioned at the experimental storage ring of the GSI
Helmholtzzentrum Darmstadt. We characterize the crystal optics and demonstrate the …