Development of Energy-Selective Neutron Imaging

A neutron transmission image gives different features depending on neutron energy. Therefore, energy-selective imaging has become increasingly popular for obtaining comprehensive information. Neutron imaging using a pulsed neutron source can offer energy-selective imaging much more easily than a reactor neutron source, since it can use the time-of-flight method for energy analysis. Furthermore, by analyzing a transmission spectrum we can obtain physical quantities such as crystallographic information, elemental information, temperature, magnetic field, and so on. Such a spectrum analysis method, namely spectroscopic imaging performed at a pulsed neutron source, is a useful method for the material analysis and inspection of industrial products. Here, the principle of the method is explained and recent results are presented for a quenched iron rod, a hydrogen storage material, and elemental distributions in stainless steel.