Curved crystals for high-resolution focusing of X and gamma rays through a Laue lens

Crystals with curved diffracting planes have been investigated as high-efficiency optical components for the realization of a Laue lens for satellite-borne experiments in astrophysics. At Sensor and Semiconduc- tor Laboratory (Ferrara, Italy) a research and development plan to implement Si and Ge curved crystals by surface grooving technique has been undertaken. The method of surface grooving allows obtaining Si and Ge curved crystals with self-standing curvature, i.e., with no need for external bending device, which is a mandatory issue in satellite-borne experiments. Si and Ge grooved crystals have been characterized by X- ray diffraction at ESRF and ILL to prove their functionality for a high-reflectivity Laue lens.