The preparation and characterization of silicon-based composites doped with BaSO۴, WO۳, and PbO nanoparticles for shielding applications in PET and nuclear medicine facilities

Objective(s): The present study aimed to design new nanoparticle-based shielding materials for photons used in single-photon emission computed tomography and positron emission tomography facilities. Materials and Methods: Initially, the mass attenuation coefficients and half value layer (HVL) of the composites were comprehensively investigated based on a silicon rubber containing various ratios of micro- and nano-barium sulfate (BaSO۴), lead oxide (PbO), and tungsten oxide (WO۳) particles at ۶۰, ۸۰, ۱۰۰, ۱۵۰, ۲۰۰, ۳۰۰, ۴۰۰, ۵۰۰, and ۶۰۰ keV photon energies using the MCNP-X۶ Monte Carlo (MC) code and WinXCOM software. In the second stage, the composites composed of ۱۰ wt% and ۲۰ wt% WO۳ and PbO particles were constructed in a liquid silicone rubber-based matrix. The mass attenuation coefficients and HVL of the designed shields were experimentally assessed using Cs-۱۳۷ and Am-۲۴۱ radioactive sources.Results: The particles sizes of PbO and WO۳ were within the range of ۵۰-۲۰۰ nanometers. The MC and measurement results indicated that the linear attenuation coefficients of the composites were augmented with the addition of all the studied nano- and micro-particles. However, the PbO composites had more significant shielding properties compared to the BaSO۴ and WO۳ composites. Conclusion: According to the results, the nanocomposites had better ability to shield γ-rays at both energies compared to the micro-composites.

Keywords:

Nanocomposite , Nanoparticles , Nuclear Medicine , radiation shielding