Ekrem Gulsevincler
Pressurized xenon-filled closed-cell Ni-Cr 70/30 and Ni-Mo 70/30 metal foams are investigated as lightweight gamma-ray shielding materials for nuclear and aerospace applications. The proposed concept combines a nickel-based metallic matrix with xenon gas confined inside closed-cell cavities, aiming to exploit both the structural advantages of metal foams and the high atomic number of xenon for enhanced photon attenuation. Computational material definitions were established for different porosity levels and xenon pressures, and the shielding behavior was evaluated using GEANT4, FLUKA, and WinXCom/XCOM-based analyses. The results show that photon attenuation is strongly energy dependent, with the highest shielding performance occurring at low gamma-ray energies where photoelectric absorption dominates. Increasing xenon pressure from 1 atm to 100 atm improves attenuation by increasing the gas density inside the closed cells, with a more pronounced effect in high-porosity configurations. Among the evaluated systems, Ni-Mo-based foams generally provide superior attenuation compared with Ni-Cr foams due to the higher atomic number and density contribution of molybdenum. The thickness-dependent shielding results further indicate that shield thickness substantially affects attenuation performance, especially at higher photon energies. The findings highlight the potential of pressurized xenon-assisted nickel-based closed-cell foams while emphasizing the need for future experimental validation, long-term gas retention tests, and geometry-resolved photon transport validation.