FOCUSING OPTICS FOR HIGH-ENERGY X-RAY-DIFFRACTION

Novel focusing optical devices have been developed for synchrotron rad iation in the energy range 40-100 keV. Firstly, a narrow-band-pass foc using energy-tuneable fixed-exit monochromator was constructed by comb ining meridionally bent Laue and Bragg crystals. Dispersion compensati on was applied to retain the high momentum resolution despite the beam divergence caused by the focusing. Next, microfocusing was achieved b y a bent multilayer arranged behind the crystal monochromator and alte rnatively by a bent Laue crystal. A 1.2 mu m-high line focus was obtai ned at 90 keV. The properties of the different set-ups are described a nd potential applications are discussed. First experiments were perfor med, investigating with high spatial resolution the residual strain gr adients in layered polycrystalline materials. The results underline th at focused high-energy synchrotron radiation can provide unique inform ation on the mesoscopic scale to the materials scientist, complementar y to existing techniques based on conventional X-ray sources, neutron scattering or electron microscopy.