Evaluation of Radiation Shielding Properties of the Polyvinyl Alcohol/Iron Oxide Polymer Composite

Gamma-ray, fast neutron and ion shielding characteristics of low-density and high-entropy Mg-Al-Ti-V-Cr-Fe-Zr-Nb alloy systems using Phy-X/PSD and SRIM programs

This study aimed to assess the radiation shielding properties of ten low-density high-entropy alloys (LWHEAs) using Phy-X/PSD software to analyze various shielding parameters, such as attenuation coefficients (μ m and μ), mean free path (λ), effective atomic number (Z eff ), and removal cross-section (Σ R ), in the energy range of Image 1 to Image 2. A comprehensive evaluation was performed to compare the attenuation outcomes provided by HEAs with a range of shielding materials documented in the literature. The study also calculated the build-up factors (BUFs) of the alloys by using the GP-fitting interpolation method. The stopping power of the alloys against H 1 / H e + 2 ions was analyzed using the SRIM Monte Carlo code, considering total stopping power (TSP) and projected range (PR). The results indicated that HEA8 (A l 3.88 C r 14.95 M o 27.58 N b 26.71 T i 13.76 Z r 13.11 ) had the best performance in terms of shielding against γ-rays, fast neutrons, and H 1 / H e + 2 ions, as it achieved the highest values of parameters such as μ m , μ, Z eff , and Σ R , along with the lowest values of HVL, TVL, λ, BUFs (Image 3 Image 4), TSP, and PR. On the other hand, HEA10 (M g 10.77 A l 11.96 M n 24.35 F e 24.75 C u 28.17 ) had the lowest BUFs in both lower (Image 5 Image 4) and higher (Image 6 Image 4) energy regions. The order of μ m for the alloys was found to be HEA5 < HEA6 < HEA9 < HEA7 < HEA10 < HEA4 < HEA2 < HEA3 < HEA1 < HEA8 . The study concluded that LWHEAs possess superior radiation shielding properties compared to conventional materials, making them a promising new class of materials for radiation shielding applications.

Micro and nano Bi2O3 filled epoxy composites: Thermal, mechanical and γ-ray attenuation properties

Polymer composites have attracted considerable attention as potential light-weight and cost-effective materials for radiation shielding and protection. In view of this, the present work focusses on development of lead-free composites of diglycidyl ether of bisphenol A (DGEBA) epoxy resin with micro (~ 10 μm) and nano (~ 20 nm) bismuth (III) oxide (Bi₂O₃) fillers, using solution casting technique. Thermal, mechanical and γ-ray attenuation properties of the composites were studied by varying the filler loading. Inclusion of the fillers into epoxy matrix was confirmed both structurally and morphologically by XRD and SEM, respectively. Thermogravimetric analysis (TGA) showed the thermal stability of composites to be as high as 400 °C. The nanocomposites exhibited relatively higher thermal stability than their micro counterparts. Among the composites, 14 wt% nano-Bi₂O₃/epoxy composites showed highest tensile strength of 326 MPa, which is about 38% higher than 30 wt% micro Bi₂O₃/epoxy composites. Mass attenuation coefficients (μ/ρ) of the composites were evaluated at γ-ray energies ranging from 0.356 to 1.332 MeV. Nanocomposites showed better γ-ray shielding at all energies (0.356, 0.511, 0.662, 1.173, 1.280 and 1.332 MeV) than micro composites with same filler loading. These studies revealed the significance of nano-sized fillers in enhancing overall performance of the composites.

Tailoring bismuth borate glasses by incorporating PbO/GeO2 for protection against nuclear radiation

Nuclear radiation shielding capabilities for a glass series 20Bi₂O₃ - xPbO - (80 - 2x)B₂O₃ - xGeO₂ (where x = 5, 10, 20, and 30 mol%) have been investigated using the Phy-X/PSD software and Monte Carlo N-Particle transport code. The mass attenuation coefficients (μ_m) of selected samples have been estimated through XCOM dependent Phy-X/PSD program and MCNP-5 code in the photon-energy range 0.015-15 MeV. So obtained μ_m values are used to calculate other γ-ray shielding parameters such as half-value layer (HVL), mean-free-path (MFP), etc. The calculated μ_m values were found to be 71.20 cm²/g, 76.03 cm²/g, 84.24 cm²/g, and 90.94 cm²/g for four glasses S₁ to S₄, respectively. The effective atomic number (Z_eff)values vary between 69.87 and 17.11 for S₁ or 75.66 and 29.11 for S₄ over 0.05-15 MeV of photon-energy. Sample S4, which has a larger PbO/GeO₂ of 30 mol% in the bismuth-borate glass, possesses the lowest MFP and HVL, providing higher radiation protection efficiency compared to all other combinations. It shows outperformance while compared the calculated parameters (HVL and MFP) with the commercial shielding glasses, different alloys, polymers, standard shielding concretes, and ceramics. Geometric Progression (G-P) was applied for evaluating the energy absorption and exposure buildup factors at energies 0.015-15 MeV with penetration depths up to 40 mfp. The buildup factors showed dependence on the MFP and photon-energy as well. The studied samples' neutron shielding behavior was also evaluated by calculating the fast neutron removal cross-section (Σ_R), i.e. found to be 0.139 cm^-1 for S₁, 0.133 cm^-1 for S₂, 0.128 cm^-1 for S_3, and 0.12 cm^-1 for S₄. The results reveal a great potential for using a glass composite sample S4 in radiation protection applications.

Polymeric composite materials for radiation shielding: a review

The rising use of radioactive elements is increasing radioactive pollution and calling for advanced materials to protect individuals. For instance, polymers are promising due to their mechanical, electrical, thermal, and multifunctional properties. Moreover, composites made of polymers and high atomic number fillers should allow to obtain material with low-weight, good flexibility, and good processability. Here we review the synthesis of polymer materials for radiation protection, with focus on the role of the nanofillers. We discuss the effectivness of polymeric materials for the absorption of fast neutrons. We also present the recycling of polymers into composites.