Monochromatic Neutron Radiography / Tomography (Bragg Edge Analysis)
Among the Neutron Imaging techniques, Energy Selective Scan, provides a very accurate microstructural characterization. This technique is based on the acquisition of a series of neutron radiography (or tomography) at different wavelengths with a monochromatic beam. The use of a monochromatic beam offers the possibility to change the contrast of the image, for the different phases, taking advantage of the abrupt change in the attenuation coefficients at the so-called Bragg cut-off. In fact, for each crystalline phase, depending on its reticular organization, there is a characteristic λ for which the scattering cross section collapses, favouring transmission. This allows to identify different metallic phases, and to obtain clues about the casting temperature or cold working.