Neutron non-destructive elemental analysis methods can be roughly divided into two, one in which the energies of emitted gamma rays are analyzed (Prompt Gamma-ray Analysis: PGA), and the other in which neutron-capture resonances are analyzed (Neutron Resonance Capture Analysis: NRCA). Although both methods enable us to precisely determine the amounts of elements contained in the sample, in some cases neither of the methods is applicable depending on the elements to be analyzed and the accompanying elements.
By combining the two methods, and utilizing the most intense pulsed neutron beam in the world delivered to Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) of Materials and Life Science Experimental Facility (MLF) at Japan Proton Accelerator Research Complex (J-PARC), we have successfully realized the synergy of the two elemental analysis methods, prompt gamma-ray analysis with the time-of-flight technique (TOF-PGA).
TOF-PGA method, by doing simultaneous analyses in both methods, enables the non-destructive elemental analysis of the samples which were difficult to be analyzed by either one of the conventional two methods.
We think that the application of TOF-PGA method is not limited to the field of nuclear energy, and that it is equally applicable to cosmochemistry (analysis of e.g. meteorites), archeology (artifacts such as earthenware), geochemistry (deep-sea samples), and environmental science (heavy-metal-contaminated soil). Samples in those fields usually involve many elements, and at the same time these are often one-of-a-kind and extremely valuable, and can not be dissolved for their analyses. Also, due to the fact that usually many elements are contained in such samples, gamma-ray peaks (as in the case of Cobalt) and neutron absorption dips are often overlapped, and accurate analyses cannot be done in conventional methods. The present method resolves this difficulty and enables accurate and reliable analysis, and therefore will further advance knowledge in those fields.
