Aiming at checking the conceptual design of the subcritical reactor, an experiment using activation technique was carried out on a depleted uranium shell of R19.4/30.0 cm with D-T neutrons. The 6 depleted uranium foils were activated at 90° with respect to the incident D beam in the shell, and distributions of 238U (n, γ) reaction rates, 238U (n, f) reaction rates, 238U (n, f) reaction rates and 238U (n, 2n) reaction rates were obtained, by measuring characteristic γ rays generated by corresponding uranium reactions. The relative uncertainties are 3.6%—3.7% for 238U (n, γ) reaction rates, 5.1%—5.9% for 238U (n, f) reaction rates and M8U (n, f) reaction rates, and 4.3%—4.7% for 238U (n, 2n) reaction rates. The experiment was simulated using MCNP5 code with ENDF66c library, and the calculation-to-experiment ratios are 0.972—1.034 for 238U (n, γ) reaction rates, 0.983—1.058 for 238U (n, f) reaction rates and 238U (n, f) reaction rates, and 0.979—1.019 for 238U (n, 2n) reaction rates.%为校验次临界能源堆的概念设计,在R19.4/30.0 cm的贫铀球壳装置上采用活化法开展14 MeV中子学积分实验.布放6片贫铀活化片于球壳中与入射D离子束90°方向上的不同位置处活化,用HPGe探测器测量238U(n,γ)反应、238U(n,f)及235U(n,f)反应和238U(n,2n)各反应产物发射的特征γ射线,得到了相应的反应率.238U(n,γ)反应率的不确定度为3.6％-3.7％,238U(n,D和235U(n,f)反应率的不确定度为5.1％-5.9％,238U(n,2n)反应率的不确定为4.3％-4.7％.用MCNP5程序在ENDF66c数据库下进行模拟计算,238U(n,γ)反应率的计算值/实验值(C/E)为0.972-1.034,238U(n,f)和235U(n,f)反应率的C/E为0.983-1.058,238U(n,2n)反应率的C/E为0.979-1.019.
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