Investigation of prompt [formula omitted]-ray neutron activation spectrometer at the Dalat research reactor using Geant4 simulation

Abstract

The prompt γ-ray activation analysis (PGAA) detector, which has been developed at the Dalat nuclear research reactor, is investigated in this study. The Geant4 model is proposed for the PGAA detector to evaluate the Compton scattering background suppression. Based on this model, the detector efficiency in the energy range from 0.1 MeV to 11 MeV was determined using the thermal neutron capture of chlorine, titanium, nitrogen, and reference sources. The detector efficiencies in the unsuppressed and suppressed modes and the difference of efficiencies in both modes were calculated. Additionally, the suppression of additional peaks of the PGAA detector was also estimated in this work. Finally, the polynomial function for the detector efficiency and the ratio of additional peaks to corresponding full-energy peaks were determined. This work makes an essential contribution to the analysis of prompt γ-ray spectrum acquired from the PGAA detector at the Dalat nuclear research reactor.