Search

Utilizing a polymer-based radiation shield offers lightweight, low cost, non-toxic compared to lead and solution for eliminating generated secondary neutrons. Incorporating silicon (i.e., one of the most abundant elements) in new applications, such as shielding, would have an impact on the economy and industry. In this study, seven potential shielding materials, composed of silicon, silicon carbide, and boron carbide embedded ethylene vinyl acetate (EVA) copolymers, are proposed. The shielding performance of these composite materials, including the attenuation coefficients (µ), the mass attenuation coefficients (µm), the half value layer (HVL), the mean free path (MFP), and the radiation protection efficiency (RPE) were examined using photon beams. Measured µm were verified against the calculated values. The averaged agreement was within ±7.4% between the experimental measurements and the theoretical calculation results. The HVL and MFP measured values for the polymer composites were lower than that for the pure EVA polymer, indicating the fillers in the polymers enhanced the shielding performance. The EVA + SiC (30%) and EVA + Si (15%) + B4C (15%) composites required the lowest thickness to stop 50% of the incident photons. The evaluation of experimental results of the RPE revealed that the polymer composites containing SiC (30%), Si (15%) + B4C (15%), or SiC (15%) + B4C (15%) succeeded in blocking 90–91% of X-rays at nearly 80 keV. However, a thicker shield of the proposed composite materials or combined layers with other high-Z materials could be used for higher energies. [ABSTRACT FROM AUTHOR]

Researchers have tested the potential of various polymer composites for use in radiation shielding. They are light and non-toxic compared to Pb and have potential as shielding in diagnostic radiology where low-energy photons are predominantly used. This study documents the production of four composites using the combination of a base, i.e. high-density polyethylene (HDPE) polymer, and four other elements/compounds, i.e. molybdenum, molybdenum carbide, tungsten, or tungsten carbide. The resulting composites were synthesized in the form of 20 disks, each with a thickness of 2 mm. The disks were irradiated by a kilovoltage X-ray source (1.5 cm2 field size). The mass attenuation coefficient (μ m), half value layer (HVL), mean free path (MFP), and equivalent atomic number of the disks were measured. We found that supplementing HDPE with additives enhanced the attenuation of beams; the μ m values of the composites were higher than that of the pure HDPE polymer. The μ m values of the measurement and calculation results were in good agreement with each other, with an average error of 5.2%. Among the three additive concentrations that were tested, i.e., 5, 10, and 15%, the 15% concentration in HDPE yielded the best shielding efficiency. Since they possess smaller values of HVL and MFP, the polymer composites containing W and WC performed the best at attenuating the radiation beams. • HDPE with Mo, W, MoC, and WC as additives can replace Pb as radiation shield. • Performance of HDPE with three additive concentrations, 5, 10, and 15%, was tested. • HDPE with 15 wt% of additives shows the highest radiation shielding efficiency. • W- and WC-HDPE composites are the best radiation shield against X-rays. • Proposed HDPE polymers are nontoxic, easy to mold, and lightweight. [ABSTRACT FROM AUTHOR]