Mohammed A Ibrahim
Unsaturated polyester (UP) composites are emerging as promising materials for fast neutron shielding applications due to their high hydrogen content, tunable composition, and ease of fabrication. However, their neutron attenuation performance needs systematic characterization and optimization. This paper aims to determine the dependence of fast neutron attenuation efficacy of UP composites reinforced with micro- and nano-fillers on material composition and neutron energy. UP resins were reinforced with varying mass fractions of microscale boron carbide and nanoscale graphene nanoplatelet fillers. The fabricated composites were characterized for density, hydrogen content, filler dispersion, and mechanical properties. Fast neutron transmission experiments were performed using a neutron generator and liquid scintillator detector setup for neutron energies ranging from 1-12 MeV. The measured transmission spectra were used to calculate important shielding parameters like linear attenuation coefficients, half-value layer thickness, and tenth-value layer thickness. The results show that nanocomposites exhibit superior neutron attenuation compared to microcomposites, with up to a four-fold enhancement in stopping power achieved with only 5 wt% graphene fillers. The neutron attenuation showed a strong dependence on neutron energy and material hydrogen content. An analytical model incorporating these parameters was developed to predict the fast neutron shielding efficacy of the composites. Overall, this work provides vital quantitative insights into microscopic shielding mechanisms in UP composites to guide the development of lightweight nanocomposites tailored for fast neutron radiation shielding.
Pages: 01-06 | 288 Views 121 Downloads