Akademik Veri Yönetim Sistemi
Results in Physics, cilt.85, 2026 (SCI-Expanded, Scopus)
In this study, the gamma-ray attenuation performance of unsaturated polyester (UPR) nanocomposites reinforced with barium oxide (BaO) nanoparticles was investigated. UPR was selected as a lightweight and easily processable polymer matrix, while BaO nanoparticles were employed due to their relatively high atomic number and potential to enhance photon attenuation in lead-free shielding systems. BaO nanoparticles were synthesized via the co-precipitation method and structurally characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The mass attenuation coefficient (μ/ρ) and half-value layer (HVL) of the composites were evaluated experimentally using Ba-133, Cs-137, and Co-60 gamma sources at photon energies of 81, 356, 662, 1173, and 1332 keV and through MCNP6.2 Monte Carlo simulations. The addition of BaO nanoparticles significantly enhanced the attenuation capability, particularly at low photon energies, with the 20 wt% BaO composite exhibiting about 27% higher μ/ρ at 81 keV and approximately 16% lower HVL at 662 keV compared with neat UPR. The agreement between experimental and simulated attenuation coefficients remained within ±3–5%, confirming the reliability of the experimental setup and Monte Carlo modeling. As a health physics application of the samples, an MCNP simulation was designed considering the 511 keV annihilation photon energy emitted from F-18 radioisotopes used in PET (Positron Emission Tomography) systems. A syringe model geometry was employed to simulate the shielding behavior of the UPR/BaO composites during radiopharmaceutical injection. In addition to the experimentally validated attenuation results, a PET syringe geometry was modeled using MCNP to provide a comparative assessment of shielding performance under realistic geometric conditions. The 20 wt% BaO composite achieved a dose ratio of approximately 84% (80–92%) relative to lead at 511 keV photon energy, confirming its potential as a lightweight, processable, and environmentally friendly alternative for PET-based nuclear medicine shielding applications.