Journal of Nuclear Fuel Cycle and Waste Technology

Neutron induced prompt gamma-ray spectroscopy(NIPS) system measures the prompt gammaray emitting by the interaction of a neutron with various materials. This system will be of great benefit to scientists worldwide, since it provides the non-destructive measurement of many element in either solid or liquid wastes. In this study, the full-energy-peak (FEP) efficiency calibration for a HPGe detector was constructed in the -ray energy range from 80 keV to 8 MeV, using 133Ba and 152Eu RI sources and 35Cl(n, )36Cl thermal neutron captured reaction. The FEP efficiency curve for the higher energies using the 35Cl(n, )36Cl reaction was normalized with the curve obtained from the RI sources, since the accurate activity of its prompt γ-ray is unknown. The average thermal neutron flux was theoretically calculated using the FEP efficiency curve for the KCl standard solutions. The NIPS system equipped with a γ-γ coincidence setup with two n-type coaxial HPGe detectors was considered in order to reduce the interfering γ-ray background. The FEP efficiency curve for the γ-γ coincidence system was also obtained for full energy range. The performance of the normal and coincidence NIPS system was tested by comparing signal-to-noise ratio in each mode using the reference sample.

Keywords

Efficiency calibration,Neutron,Prompt gamma-ray,Coincidence,HPGe detector