Magnifying effect by neutron diffraction on cylindrically bent perfect crystal (BPC) of Si in fully asymmetric diffraction geometry

Abstract

Low absorption of neutrons in Si crystal enables using the fully asymmetric diffraction geometry (FAD) of the single crystal slab in which neutron beam can pass inside a rather long distance more than ten centimetres. A practical exploitation of this property can be namely in the case of bent perfect crystals when due to the homogeneous deformation a neutron beam can meet, on the path, the diffraction condition only once and its attenuation is mainly brought about by absorption or incoherent scattering. In this paper a large one dimensional magnifying property of the FAD geometry of the cylindrically bent perfect crystal slab of Si is demonstrated. This property can be used in high resolution small angle neutron scattering as well as in neutron imaging.