Neutron diffractometer using Bragg diffraction optics for high resolution strain/stress measurements

Novel modification of the neutron diffraction method - method of Bragg Diffraction Angle Analysis (BDAA), which is routinely used for strain/stress investigations in polycrystalline materials in NPI Rez is presented. It provides sufficiently high resolution (FWHM of the instrumental Delta d/d - profile can be less than 2x10(-3) at d=0.2 nm) permitting investigations of both the macro- and microstrains of the order 10(-4). Basic feature of the modification is the exploitation of Bragg diffraction optics - focusing in real and momentum space - using curved perfect crystal slabs. Properties of this modification are documented by results of experimental measurements.