Influence Analysis of B4c Content on the Neutron Shielding Performance of B4c/Al

Abstract

B 4 C/Al composites have been widely studied and used as neutron absorbing materials in various application fields because of its relatively simple preparation process, good mechanical properties, and low raw material prices. B 4 C content is the major factor affecting the neutron shielding performance of B 4 C/Al composites. A photo-neutron source driven by a 15 MeV electron linear accelerator has been used to measure the neutron shielding performance of the B 4 C/Al composite plates with B 4 C weight percentages of 16.85% and 31%, respectively. Based on the measurement result, the thermal neutron macroscopic cross sections of the B 4 C(16.85 wt%)/Al composite and B 4 C(31 wt%)/Al composite were 13.97 cm -1 and 25.58 cm -1 , respectively. The measurement results showed that the B 4 C/Al composites have good shielding performance for neutrons with energies lower than 10 eV, especially for thermal neutrons, and the 1.02 mm thickness of B 4 C(31 wt%)/Al composite was able to absorb 90.91% of thermal neutrons. Experimental measurements were compared with calculation results. The experimental measurement result of the thermal neutron macroscopic absorption cross section was smaller than the calculated data, and the relative deviations of the experimental measurement results and calculation data of the thermal neutron macroscopic cross sections of B 4 C(16.85 wt%)/Al and B 4 C(31 wt%)/Al composites were -13.65% and -12.52%, respectively. The Monte Carlo N-Particle Transport code was used to calculate the neutron shielding performance of B 4 C/Al with different B 4 C content, and the shielding performance of the B 4 C/Al composites for low-energy neutrons was approximately linearly proportional to the B 4 C content, especially for the thermal neutron.

Keywords: B4C/Al composites, B4C content, neutron, shielding performance