Neutron Resonance Capture and Transmission Analysis

Abstract

AbstractNeutrons can be used as probes to investigate and study properties of materials and objects. The deep penetration of neutrons into matter allows the study of bulk properties. One evolving activity in this field concerns the existence of resonances in neutron‐induced reaction cross sections in the neutron energy range from thermal up to a few megaelectronvolts for certain nuclides. Since these resonances appear at neutron energies, which are specific for each nuclide, they are very suitable for the determination of the elemental composition of objects and materials. Neutron resonance capture analysis (NRCA) and neutron resonance transmission analysis (NRTA) are two methods used for exploiting the resonance structure in the neutron‐induced reaction cross sections. Both methods are nondestructive, determine the bulk elemental composition, do not require any sample preparation, and result in a negligible residual activity. NRCA is applicable to almost all stable elements, while NRTA is preferred for light elements or nuclei near a closed shell. Quantitative NRCA and NRTA have been used for the analysis of archeological objects and reference materials used for cross‐section measurements. Other applications of neutron resonance spectroscopy range from radiography of nuclear fuel (including spent fuel), detection of explosives and drugs, to thermometry and diamond mining.