High diffraction efficiency with hard X-rays through a thick silicon crystal bent by carbon fiber deposition

The diffraction capability of two crystalline silicon plates bent by carbon fiber deposition has been studied. The performed treatment induced a permanent curvature in the samples, resulting in an increase of the diffraction efficiency. The obtained efficiencies are constant over a wide angular range and close to the theoretical expectations, meaning that the curvatures were homogeneous. Most importantly, the bending technique allowed the manufacture of bent samples up to 5 mm thick and with a radius of curvature down to 30 m. With such a technique, the fabrication of crystals for the realization of a hard X-ray concentrator (Laue lens) for astrophysical purposes is enabled.