Heavy‑metal oxide glass as a compact gamma‑ray shield: a geant4 monte‑carlo study

Abstract

Relevance: in recent years, the selection of radiation shielding materials has increasingly prioritized criteria such as environmental safety, high density, and optical transparency. The toxicity and disposal challenges associated with conventional lead-based silicate glasses have necessitated the development of modern alternatives. In this context, heavy-metal oxide glasses—particularly those based on Bi₂O₃–MoO₃–B₂O₃ compositions—have emerged as promising non-toxic, transparent, and highly efficient gamma-ray shielding materials. The tightening of radiation safety standards and the growing demand for compact shielding solutions further underscore the importance of such materials.

Aim: to investigate the gamma-ray attenuation properties of heavy-metal oxide glass based on Bi₂O–MoO–BO₃ in the energy range of 0.1–20 MeV, using Geant4 Monte Carlo simulations. The study aims to determine key dosimetry parameters including the mass attenuation coefficient, half-value layer (HVL), absorbed dose, and linear energy transfer (LET) spectra.

Methods: photon absorption and transmission through a 2 cm thick Bi–Mo–B glass slab were modeled using the Geant4 toolkit (version 11.3.2) based on the Monte Carlo method across the photon energy range of 0.1–20 MeV. The obtained results were compared with XCOM database values, experimental measurements, and FLUKA simulation outputs.

Results: the simulation results demonstrated the high effectiveness of Bi₂O₃–MoO₃–B₂O₃-based glass in attenuating gamma radiation. In the 100–500 keV range, the mass attenuation coefficient varied from 0.82 to 0.42 cm²/g, with HVL values 3 to 6 times lower than those of borosilicate glass and concrete. The absorbed dose recorded behind the shield was negligible at low photon energies and increased significantly only above 10 MeV. LET spectra indicated a dominance of low-LET radiation, suggesting minimal radiobiological risk. Geant4-based results were in strong agreement with both FLUKA calculations and available experimental data.