Optimization of PGNAA Detector Shielding by Combining Monte Carlo Simulation with an Optimization Algorithm

Abstract Detector shielding is essential in prompt gamma neutron activation analysis (PGNAA) systems to attenuate neutrons reaching the detector and suppress gamma-ray background. A Monte Carlo simulation coupled with an optimization algorithm was used to optimize the detector shielding and detector-to-sample distance. Among 35 evaluated candidates, 8 cm Pb and 5 cm BPE at 33 cm yielded the highest simulated SNR of 0.209. Experiments with the same shield also gave the highest SNR of 0.157 at 33 cm, 185.5% higher than at 25 cm. The agreement between simulation and experiment demonstrates the effectiveness of the method.