Materials Behavior & Characterization: Modeling of Neutron Transmission spectra from single crystal to polycrystal
Still in its infancy, the neutron Bragg-edge transmission (NBET) provides reach energy dispersive data and is promising to evolve into an efficient technique to obtain three-dimensional strain maps within the bulk of materials. To date this technique has been applied to isotropic materials without the consideration of preferential grain orientations (texture). In this presentation, an approach to model NBET starting from a single crystal to a distribution of crystals is presented. The simulation engine allows the user to define individual grain size, mosaic distribution per grain, grain orientation, and strain/stress distribution across the specimen. Simulation of neutron transmission curves for single crystal copper bench-marked with experimental data from literature is presented. Simulations of Neutron Bragg-edge measurements for selected materials are compared with Neutron Bragg-edge measurement. Effect of crystallographic texture on neutron transmission curves are compared with measurements data recorded on a highly textured Inconel alloy. The elastically induced shifts of single crystal Bragg- dips and Bragg edges are demonstrated.