针对车载D-D加速器中子源的紧凑、轻量化屏蔽材料优化设计研究

摘要

为减小D-D加速器中子源的体积和质量,本文结合遗传算法和MCNP程序建立了一种针对快中子的优化设计紧凑、轻量化屏蔽材料的方法.基于此方法,设计得到了一系列材料样本,采用MCNP程序模拟了各材料对D-D中子的屏蔽性能,并与传统材料PB202、PE-30％B、M-L1、M-L2进行了对比.为直观比较屏蔽材料的性能,假设加速器生物屏蔽体为同轴渐缩圆柱体结构,对不同材料所需体积及质量进行了对比,结果显示,SDGa性能较好,可同时满足紧凑化与轻量化的需求.同时,对SDG3和SDG3*辐照1 000h后的活化伽马剂量率进行了评估,结果显示其活化影响可忽略.%To minimize the size and weight of the vehicle-mounted accelerator-driven D-D neutron source, optimization of compact and lightweight radiation shielding material for the fast neutrons was carried out, which employed genetic algorithms and the MCNP code. Based on this method, a series of material samples were designed and the shielding performance was compared with that of traditional materials such as PB202, PE-30％B, M-L1and M-L2for the D-D neutron by MCNP. To compare the shielding performance conveniently, both of the needed volume and weight were compared while assuming the shielding as a coaxial tapered cylinder. The results show that the SDGa can satisfy the requirements of lightweight and compact simultaneously. At the same time, the activation gamma dose rates of SDG3and SDG3* after 1 000hirradiation were evaluated, and the results show that the activation can be neglected.