Validation of GEANT4 simulation for active materials interrogation using nuclear resonance fluorescence

This study validates the GEANT4 simulation toolkit's effectiveness in modeling Nuclear Resonance Fluorescence (NRF) for Non-Destructive Assay (NDA) applications, focusing on isotopes 11 B and 238 U, which exhibit distinct NRF characteristics. Using experimental data from the High-Intensity γ-ray Source (HIγS) facility, the study benchmarks GEANT4's capability in simulating critical NRF interactions, such as spectra peak positions, angular distributions, and yield dependencies on target thickness. For 11 B, GEANT4 successfully replicated NRF peaks at 2125, 4440, and 5020 keV, achieving alignment within ±1% of experimental values. For 238 U, simulations reproduced NRF yield saturation as target thickness increased, validating the toolkit's handling of self-absorption and scattering effects, which are critical for applications involving high-density, shielded materials. These findings confirm GEANT4's robustness in simulating NRF phenomena, making it suitable for designing advanced NDA systems for security applications where isotope-specific detection and effective shielding penetration are essential. The validated toolkit provides a reliable foundation for developing accurate, efficient, and secure nuclear detection technologies.