Axisymmetric and Focusing Analyzers to Enable Efficient Powder and Residual Stress Neutron Diffractometers

Although thermal and cold neutron scattering is widely used, and is critical for success in many areas of materials science and engineering, relatively low neutron fluxes severely limit applications of not only laboratory neutrons generators, but also large national neutron facilities. State-of-the-art thermal and cold neutron sources are large expensive national facilities, which serve diverse community of scientific and industrial users. The constant need to improve the instruments performance, stems from the fact that neutron methods are gaining in popularity, and becoming more and more powerful, while new neutron sources are not being constructed, so as to keep pace with the developments and needs of the scientific community. Small research reactors at universities and National Labs, and laboratory-based neutron generators, are necessary not only for education and training, but also when samples cannot be transported to other facilities. However, the standard neutron techniques, which were developed for high-flux facilities, require much higher efficiencies to be used effectively with the low fluxes of small sources. Thus, the efficient use of neutron sources, such as with our proposed analyzer, is important for the progress and broader use of these neutron techniques. We strive to achieve the goal of efficient use of available thermal and cold neutrons, by introducing here, novel analyzers for powder diffraction and stress-strain measurements. These analyzers will enable polychromatic cold and thermal neutron diffractometers, which will have much higher throughput than existing instruments. At large national facilities, such as at Oak Ridge National Laboratory, these analyzers would enable very fast instruments for screening of multiple samples, for measuring kinetic processes, or for measuring residual stress tensors.