Bragg-edge elastic strain tomography for in situ systems from energy-resolved neutron transmission imaging

Technological developments in high-resolution time-of-flight neutron detectors have raised the prospect of tomographic reconstruction of elastic strain fields from Bragg-edge strain images. This approach holds the potential to provide a unique window into the full triaxial stress field within solid samples. Recent work has provided an algorithm to achieve tomographic reconstruction for systems subject to in situ loads in the absence of residual stress. This paper details an experimental proof of concept for this algorithm involving the full reconstruction of a biaxial strain field within a nontrivial steel sample. Aside from a small systematic error present within individual measurements, the experiment was a success and now serves as a practical demonstration of Bragg-edge transmission strain tomography for systems under in situ loads.