基于强流脉冲离子束的中子辐照模拟装置及评价技术  

Equipment for Emulated Neutron Irradiation and Evaluation Based on High-Intensity Pulsed Ion Beams

作　　者：朱小鹏[1] 田齐擎 杨振 任尚 雷明凯[1] ZHU Xiaopeng;TIAN Qiqing;YANG Zhen;REN Shang;LEI Mingkai(Dalian University of Technology,Dalian,Liaoning Prov.116024,China)

机构地区：[1]大连理工大学,辽宁大连116024

出　　处：《中国核电》2024年第2期150-156,共7页China Nuclear Power

基　　金：国家自然科学基金重点项目(U21B2078);面上项目(52371054)。

摘　　要：依据高能原子辐照与中子辐照的初级离位原子(PKA)能谱相似性,基于TEMP-6M型强流脉冲离子束(HIPIB)系统,研发了一种中子辐照模拟装置,该装置以磁绝缘离子二极管伴生的强流脉冲二次电子束流实现0.1 MeV以上高能离子的高效率中和,获得动能为0.1~1 MeV、脉冲宽度为120~160 ns、脉冲辐照剂量为1012~10^(15)n/cm^(2)的强流脉冲原子或混合束,原子占比为85%~100%。通过辐照缺陷原位差热分析方法,快速确定材料缺陷数量、密度及dpa损伤速率等抗中子辐照性能评价指标。以核级AISI 304奥氏体不锈钢为例,计算PKA相似性定标曲线,采用220~280 keV的C原子等效1.8~2.3 MeV中子进行辐照模拟,调节名义束流能量密度0.5~4 J/cm^(2),实测辐照剂量范围为0.46×10^(13)~8.55×10^(13)n/cm^(2),热分析确定Frenkel缺陷密度为1.99×10^(16)~2.90×10^(17)/cm^(2),外推预测奥氏体不锈钢在1021n/cm^(2)中子剂量条件下的辐照损伤为500 dpa量级,适用于核电厂结构材料60年服役寿期评价需求。Based on TEMP-6M system of high-intensity pulsed ion beams(HIPIBs),a novel equipment of high-intensity pulsed atom beams to emulate neutron irradiation is developed according to the similarity of primary knock-on atom(PKA)energy spectrums under high-energy atom and neutron irradiation.The equipment generates high-intensity pulsed atom beams from magnetically insulated ion diodes by which highly efficient neutralizing of high energy ions above 0.1 MeV is realized through accompanied high-intensity pulsed secondary electrons,leading to high-intensity pulsed atom or mixed beams with kinetic energy of 0.1~1 MeV,pulse duration of 120~160 ns,and emulated neutron dose in a pulse of 1012~10^(15) n/cm^(2) with high atom ratio of 85%~100%.An in-situ differential scanning calorimetric analysis method is employed to quantify the total number and areal density of point defects as well as dpa damage etc.for evaluating the irradiation resistance of concerned materials.A case study of nuclear grade AISI 304 austenitic stainless steel is demonstrated by selecting 220~280 keV carbon atom beam to emulate 1.8~2.3 MeV neutron irradiation,according to the calculated equivalent relation on PKA energy spectrum similarity.The experimental irradiation doses are obtained in the range of 0.46×10^(13)~8.55×10^(13) n/cm^(2) by controlling a nominal energy fluence within 0.5~4 J/cm^(2) per pulse.The in-situ differential scanning calorimetric analysis reveals Frenkel defect density of 1.99×10^(16)~2.90×10^(17)/cm^(2).The accumulated damage of the austenitic stainless steel is estimated up to 500 dpa order under a total neutron dose of 1021 n/cm^(2) by extrapolating the experimental damage rate,which is applicable for evaluating irradiation resistance of structural materials in nuclear power plants for their sixty-year service lifetime.

关 键 词：中子辐照 强流脉冲离子束 强流脉冲原子束 初级离位原子 原位差热分析 

分 类 号：TL929[核科学技术—核燃料循环与材料]