Fast neutron surface strain scanning with high spatial resolution

Highlights: • Non-destructive neutron strain profiles assessment from the surface to bulk • Neutron fast and high spatial resolved strain profiles analysis • Correction of through neutron surface strain profile from spurious strains • Deconvolution of measured strain profile within neutron gauge volume • Assessment of intrinsic strain profile after manufacturing process from the surface -- Abstract: A method for near-surface strain scanning measurements using neutron diffraction with large gauge volumes is described. The approach corrects for pseudo (spurious) strains related to partially illuminated gauge volumes and enables deconvolution of the large gauge volume measurements into the assumed real profile. It was validated against X-ray and neutron diffraction experiments with very high spatial resolution. The analysis of the results shows that neutron diffraction based strain measurements with standard (or large) sized gauge volumes are possible to reproduce the real strain profile free of artificial effects related to partial illumination. Compared to measurements with smaller gauge volumes gains in counting time of up to a factor of fifteen can be achieved without appreciable loss in spatial resolution.