High-density lead-free alloys for compact and sustainable photon shielding: a Monte Carlo and benchmarking study

The quest for next-generation radiation shielding hinges on finding lead-free alloys that balance high density with environmental safety. In this work, we targeted three transition metal arsenides (VAs, MoAs, and TaAs) to determine their efficacy against ionizing radiation across a wide energy range from 0.015 MeV to 15 MeV. By leveraging the Geant4 Monte Carlo toolkit and benchmarking against the XCOM database, we achieved high-fidelity simulations with deviations below 1%. Among the candidates, TaAs demonstrated the highest photon attenuation efficiency, characterized by a linear attenuation coefficient of μ = 1.463 cm−1 at 0.5 MeV and a half-value layer of λ½ = 0.47 cm at 0.5 MeV. Critically, at a thickness of 0.1 cm, TaAs delivers a dose reduction of over 50% relative to VAs. Statistical reliability was rigorously validated using the Kolmogorov–Smirnov test (p = 1.00), confirming no significant difference between simulated and theoretical XCOM data distributions. These findings establish TaAs not merely as a replacement for conventional materials, but as compact, lead-free shielding alternative optimized for space-constrained diagnostic systems.