Multiplexing Focusing Analyzer for Efficient Stress-Strain Measurements

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 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 propose to design and demonstrate novel diffractive optical device, which will enable very efficient residual stress neutron diffractometers The proposed device will be a multi-foil analyzer, where each foil is constructed of focusing bent single crystals of Si Such device will enable polychromatic residual stress neutron diffraction At large national facilities, such as at Oak Ridge National Laboratory, these analyzers would enable very fast measurements for determining residual stress tensors, raster large samples or screen multiple samples The outcome of this project would be the demonstration of commercial devices, novel neutron optical components, which could be utilized to improve the performance of existing instruments or build novel neutron scattering instruments at DOE neutron facilities and commercial laboratory neutron sources These new devices will widen the scope of research conducted using neutrons and enable measurements not feasible at present