Investigation of the effect of boric acid concentration on neutron reflection coefficient

In this study, the neutron reflection coefficient from boric acid solutions was measured at ten concentrations from 1.6 g/L to 16 g/L and thicknesses from 1 cm to 15 cm. The neutron-reflecting solutions were prepared using pure water with a conductivity of 0.08 μS/cm and boric acid produced by AppliChem, Germany. A 5.2 Ci neutron source and a BF 3 neutron detector housed inside a cylindrical cadmium shield with a thickness of 1.45 cm were used to measure the intensity of neutrons reflected from the solutions. At a concentration of 16 g/L, the saturation thickness of solution for neutron reflection was found to be 14 cm. The experimental results also indicated that the solution of 1.6 g/L boric acid concentration reduces neutron reflection by 5.2 %. Also this value was calculated using the diffusion equation about 5.3 %. Additionally, for a concentration of 16 g/L the percentage reduction in neutron reflection, obtained from both measurements and albedo calculations using the diffusion equation, were 33.1 % and 28.6 %, respectively.