Analysis of 14-MeV neutron induced gamma-ray spectra using multiwavelets

Neutron-based methods of bulk material analysis are used to detect contraband in cargo, characterize coal and cement, and identify unexploded ordnance, among other applications. Characteristic gamma rays produced in nuclear reactions (inelastic neutron scattering, thermal neutron capture, and activation) initiated by 14-MeV neutrons in the volume of an irradiated object are utilized for its elemental identification. In many situations, automated methods of spectral analysis and decision analytics are required. In this study, a spectrum analysis technique based on wavelets was developed, which determines elemental intensities using peak areas corresponding to characteristic photons. The algorithm was evaluated using experimental data measured with a 14-MeV pulse neutron source and high-resolution and low-resolution photon detectors. It was shown that this technique provides quick, accurate, and objective analysis of gamma-ray spectra.