Techniques for Neutron Stress Determination with High Spatial Resolution

A number of sub-surface strain measurement problems require spatial resolutions of the order of 10(-1) mm to be meaningful. The use of neutron diffraction can be both time effective and otherwise advantageous compared to synchrotron diffraction if measurement directions and beam shapes are chosen such that scattered intensity is maximized. The first point refers to those directions and specimen orientations for which the gage volume orientation can be kept constant. They can be chosen such that preferred orientation boosts the diffracted intensity. The second point refers to the shaping of the incident beam for maximizing the illuminated volume in the material even for curved specimens. Guidelines and limitations of such high spatial resolution measurements are discussed.