用于车载加速器中子源的边缘冷却靶结构研究  

Edge-Cooling Target Structure for Transportable Accelerator-Driven Neutron Source

作　　者：李晓博 胡耀程 范晶晶 李竞伦 乔朝蓬 谢宇鹏 马宝龙 吕永盛 刘蕴韬[2] 李玮[2] 王盛[1] LI Xiaobo;HU Yaocheng;FAN Jingjing;LI Jinglun;QIAO Zhaopeng;XIE Yupeng;MA Baolong;L Yongsheng;LIU Yuntao;LI Wei;WANG Sheng(School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an 710049,China;Comprehensive Research Department of Nuclear Technology,China Institute Atom Energy,Beijing 102413,China)

机构地区：[1]西安交通大学核科学与技术学院,西安710049 [2]中国原子能科学研究院核技术综合研究所,北京102413

出　　处：《西安交通大学学报》2023年第6期160-171,共12页Journal of Xi'an Jiaotong University

基　　金：广东省基础与应用基础研究基金资助项目(2020B1515120035);中国核工业集团有限公司领创科研项目;日本理化学研究所International Program Associate(IPA)项目。

摘　　要：为解决车载加速器中子源锂靶出射中子衰减的问题,提出了冷却水在侧面流动的边缘冷却靶结构,研究其辐照损伤、冷却效果和出射中子品质等性能。在靶结构中引入由钒制成的中间层,从氢原子扩散和辐照损伤的角度分析了质子对靶结构材料的影响;基于有限元软件COMSOL Multiphysics,建立了不同质子束流轰击下的共轭传热模型来预测锂靶温度,并通过实验进行了验证;采用蒙特卡罗方法比较了靶结构的前冲方向中子产额,并对边缘冷却靶结构的感生放射性进行了评估。结果表明:钒中间层的引入可以有效促进氢原子的扩散和容纳过程,减轻氢脆对铜基板的影响;对于功率为250W、半径大于0.75cm的高斯分布质子束斑,边缘冷却靶结构的最高温度可以控制在140℃以下,冷却模拟结果相比于实验结果更为保守;边缘冷却靶结构在前冲方向的中子产额损失更小,具有10%左右的优势。边缘冷却靶结构在保证高效冷却的基础上,提高了前冲方向的中子产额,在车载加速器中子源上具有长寿且可靠运行的潜力,可为靶结构的相关研究提供参考。To solve the problem of emitted neutron attenuation of lithium target of the transportable accelerator-driven neutron source(TANS),the edge-cooling target structure in which the cooling water circulates through a channel along the side of substrate,was proposed,and its performance was studied such as irradiation damage,cooling effect,and quality of emitted neutron.Vanadium interlayer was introduced in the target structure,and proton effect on target structural materials was tentatively analyzed from perspectives of hydrogen diffusion and irradiation damage.Based on the software using finite element method,COMSOL Multiphysics,conjugate heat transfer models under proton beams with different distributions were built for the evaluation of lithium target temperature.The accuracy of simulation result was verified by cooling experiment.The neutron yields of target structures in forward direction were compared according to calculation using the Monte Carlo method.And the induced radioactivity of edge-cooling target structure was evaluated.The results showed that the vanadium interlayer could effectively promote the process of hydrogen diffusion and absorption,and reduce the influence of hydrogen embrittlement on copper substrate.The maximum temperature of lithium target under 250 W proton beam in Gaussian distribution with a radius greater than 0.75 cm was predicted to be below 140℃for edge-cooling target structure,and simulation results were more conservative than the experimental results.The edge-cooling target structure had a less reduction on neutron yield in forward direction,and the advantage was about 10%.On the basis of efficient cooling,the edge-cooling target structure can increase the neutron yield in forward direction,and has the ability of long life and reliable operation on TANS.Meanwhile,this study can provide reference for the related research of target structure.

关 键 词：锂靶 车载加速器中子源 中子衰减 边缘冷却靶结构 

分 类 号：O571.53[理学—粒子物理与原子核物理]