Neutron and photon shielding competences of aluminum open-cell foams filled with different epoxy mixtures: An experimental study

Highlights: • New ten composite materials were fabricated using open-cell aluminum metal foams. • Transmission measuremets were performed for X and γ-rays. • Equivalent absorbed dose for fast neutrons were measured with BF3 neutron detector. • MAC, LAC, Zeff, EABF and EBF parameters were obtained. • Samples produced with small cell metal foams were better for radiation shielding. In this study, ten open-cell aluminum foams with 30 mm thickness 2 pores/cm and 10 mm thickness 16 pores/cm pore sizes encoded A1-A5 and B1–B5 respectively were fabricated by filling with different mixtures which have Epoxy_(60wt%)-B₂O_3(20wt%)-CeO_2(15wt%)-(BaO, Cr₂O₃, WO₃, Bi₂O₃, TiO₂) _(5wt%) chemical compositions. At first, gamma transmission measurements of the manufactured samples were achieved employing an Ultra Ge detector for 30.9, 59.54, 75, 81, 276, 303, 356, 384, and 662 keV photon energies. The foam samples were also irradiated with 6 MV energy X-rays via a linear accelerator (LINAC). The mass attenuation coefficients (MACs) of the samples and further photon protection parameters derived from MAC were computed with the data acquired from those measurements. It was found that the WO₃ and B₂O₃ doped metal foams had the highest MAC values, whereas the lowest MAC values belonged to the TiO₂ doped samples. Half Value Layers (HVL) obtained for two different metal foam samples of 30 mm and 10 mm thickness with Bi₂O₃ doped were found as 0.096cm-2.962 cm and 0.090 cm–2.921 cm, respectively. While the effective atomic numbers (Z_effs) of the WO₃ and Bi₂O₃ added samples were of the highest values, the Energy absorption and Exposure Buildup Factors (EABF and EBF) calculated with Py-MLBUF in the energy range of 0.015–15 MeV were obtained as minimum compared to others. Finally, the shielding potential of the prepared samples against fast neutrons was assessed by performing equivalent dose measurements (EAD) and calculating macroscopic cross section (∑_R) values. In A and B series metal foams, it was observed that the ∑_R value was the highest in WO₃-doped samples and got 0.1691 cm⁻¹ and 0.1785 cm⁻¹ values, respectively. It was also observed that the absorbed dose rates varied between 23% and 46%. It was concluded that B3 and B4 metal foams with thinner and higher pore sizes and doped with heavy oxides (WO₃ and Bi₂O₃) could be used as an alternative shield material.