Research on the separation of capture and inelastic scattering gamma-ray spectra in prompt gamma neutron activation analysis technology based on direct-current neutron generators

This study investigates the separation of thermal neutron capture spectra and fast neutron inelastic scattering spectra in gamma-ray spectra acquired from a prompt gamma neutron activation analysis setup. Using a direct current deuterium-tritium neutron generator and a bismuth germanate scintillation detector as the cores, a high signal-to-noise-ratio experimental platform for aqueous sample detection was constructed. Thermal neutron self-shielding correction factors (fC) and fast neutron inelastic scattering self-shielding correction factors (fIS) were obtained through Monte Carlo simulations and experimental measurements. Gamma spectra from experimental tests underwent inversion calculations, ultimately yielding single-element thermal neutron capture gamma spectra and fast neutron inelastic scattering gamma spectra. A single-element response spectrum library was established, achieving the separation of the aforementioned capture and inelastic spectra. The pre-set test samples were analyzed based on the constructed library, further validating the separating performance of the capture and inelastic spectra and the effectiveness of the spectrum library analysis methodology.