Development of lightweight and highly efficient fast neutrons composites shields based on epoxy, UHMWPE fibres and boron carbide particles

Abstract

In a vision to design wearable and lightweight protective thermal neutrons shields, a new hybrid composite was developed from Ultra High Molecular Weight Polyethylene (UHMWPE) fibres, epoxy and boron carbide (B4C) particles. The hybrid constituents were selected in a way to maximize both the shielding performances and the overall mechanical behaviour. Indeed, two first constituents of the hybrid attenuate the incident neutrons through scattering, while the B4C particles mainly interact with neutrons by absorption. More importantly, the UHMWPE fibres, as one of the strongest polymeric fibres, were also chosen to sustain the mechanical loads and provide the requested flexibility. The measurements were performed using an optimized experimental setup at NUR research reactor, Algiers. The effect of the amount of the B4C particles was also studied to maximize the shielding ability. The obtained results confirmed the high shielding efficiency of all the developed materials. Meanwhile, the best performance was recorded at B4C amount of 10 wt% with a macroscopic cross-section (Σ) of 0.188 cm−1 equivalent to a mean free path (λ) of 3.7 cm. In general, the developed materials performed better than the traditional neutrons shields and can be seen as promising materials for the intended use.