Curved crystals as high-efficiency optical components for focusing of X and gamma rays through a Laue lens

A Laue lens is an optical component to focus hard X-ray photons through Bragg diffraction in Laue geometry within a properly arranged array of crystals. For a Laue lens a significantly important field of application is represented by astrophysics. In fact, in hard X-ray astronomy many celestial sources emitting high-energy photons are very interesting candidates for investigation. It is widely acknowledged that a Laue lens would achieve a gain in sensitivity by one or two orders of magnitude with respect to existing telescopes in the hard X-ray/soft gamma-ray domain (>100 keV). Observations of many violent phenomena occurring in our Galaxy would take advantage of this kind of concentrator. As an example, a hot topic in astrophysics that may benefit from this important breakthrough is high-precision mapping of celestial positron sources. A Laue lens would enable a study of the distribution of the annihilation line at 511 keV with higher resolution than for currently operating instruments, thus bringing new clues concerning these still elusive sources of antimatter. As another, a Laue lens would serve for high-quality imaging in nuclear medicine, e.g., it would improve gamma-ray detection in Single Photon Emission Computed Tomography (SPECT) with better resolution, leading to a lower radioactive dose being imparted to the patient, because there is no need for tomography scanning.