Evaluation of bismuth oxide nanoparticles for enhanced gamma-ray/neutron shielding in HDPE-based composites

In the present study the shielding efficiencies of gamma and neutron radiations for fabricated composites using high-density polyethylene (HDPE) via the sol-gel method were investigated. These lightweight, low-cost, and ductile materials incorporate xBi₂O₃ nanoparticles (x = 4.0 %, 12.0 %, 20.0 %, 30.0 %, and 40 %) as a non-toxic nanofiller. The study employed X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) to characterize the Bi₂O₃/HDPE nanocomposites. The effectiveness of these composites in attenuating gamma-ray was assessed by using an HPGe detector. Measurements were conducted across various gamma-ray energies (121, 244, 334, 444, 778, 963, 1112, and 1408 keV) emitted by a standard Eu-152 point source. The relationship between mass attenuation coefficients (μ_m) and the Bi₂O₃ loading was investigated at each energy level experimentally and theoretically. Using other shielding parameters, such as half-value layer (HVL) and mean free path (MFP), were also calculated. Total macroscopic neutron cross-section (ΣT) of the composites was also determined using an Am241-Be (α, n) neutron source. It was observed that gamma and neutron shielding properties were improved due to increasing amount of Bi₂O₃ nanoparticles in the composite.