On the physical, chemical, and neutron shielding properties of polyethylene/boron carbide composites

摘要

Monte Carlo methods are used for solving difficult stochastic problems in radiation shielding applications. The aim of this paper is to show the possibility of using the Monte Carlo code (MCBEND (R)) for evaluation and optimization of polyethylene with high boron loadings (for up to 40%) to reach better neutron shielding against fast neutrons (Am-Be neutron source). Boron is incorporated in polyethylene as boron carbide (B4C). MCBEND (R) (Monte Carlo code developed by ANSWERS) is used to simulate neutron transport through the developed borated polyethylene composites. In order to verify the computer simulations, neutron detection and data acquisition systems have been assembled, modified, and thoroughly tested for shielding efficiency. It is shown that borated composite with 10% of boron content showed the highest experimental mass removal cross section. Moreover, composite formulation with 10% of boron shows optimum density, morphology, mechanical attributes, and thermal stability than that of the neat polyethylene matrix. A comparison of experimental and simulation mass removal cross sections shows that the geometry and physics models proposed in this work are in close agreement, with maximum relative difference of not more than 15%.