Investigation of prompt y-ray neutron activation spectrometer at the Dalat research reactor using Geant4 simulation

The prompt y-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 y-ray spectrum acquired from the PGAA detector at the Dalat nuclear research reactor.

Automated summary

This study investigates the prompt gamma-ray activation analysis (PGAA) detector developed at the Dalat nuclear research reactor. A Geant4 model is proposed to evaluate the suppression of Compton scattering background in the PGAA detector, and the detector efficiency in the energy range from 0.1 MeV to 11 MeV is determined. The efficiency in both unsuppressed and suppressed modes, as well as the difference between them, is calculated. The suppression of additional peaks in the PGAA detector is also estimated, and a polynomial function for the detector efficiency and the ratio of additional peaks to corresponding full-energy peaks is determined.