First observation of meridional focusing of an X-ray beam using diffraction by a crystal with a transverse groove

The possibility of concentrating a synchrotron X-ray beam using diffraction by a single crystal with a properly designed transverse groove on its surface, suggested earlier, has been studied experimentally. Here, the first experimental demonstration of this effect is reported, performed on beamline BM5 at the ESRF. The experimental result confirms the theoretical model.