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

Abstract

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 BF₃ 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.