Measurement of ²³⁸U(n,2n) Reaction Rate in Depleted Uranium Sphere

The ²³⁸U(n,2n) reaction rates of two depleted uranium spheres were measured. The depleted uranium spheres were irradiated by D-T neutron at PD-300 accelerator. The intensity of neutron source was monitored by the associated-alpha particles from the T(d,n)He reaction. After radiation, the activated gamma rays of uranium foils in the 45° hole of uranium spheres were measured using HPGe detector. The ²³⁸U(n,2n) reaction rates of two depleted uranium spheres were calculated using Monte-Carlo simulation. It shows that the ²³⁸U(n,2n) reaction rates from experiments are agreed with the calculations. The change of ²³⁸U(n,2n) reaction rate with the radius r of depleted uranium sphere is obeyed approximately the distribution of e^-ar/r².