小角中子散射谱仪放射性样品测量装置研制  

Development of radioactive sample measurement device for small-angle neutron scattering spectrometer

作　　者：胡文耀 闫士博 李天富[1] 王子军[1] 陈忠 刘荣灯[1] 王成龙 贺新福[1] 冉怀昌 孙凯[1] 陈东风[1] HU Wenyao;YAN Shibo;LI Tianfu;WANG Zijun;CHEN Zhong;LIU Rongdeng;WANG Chenglong;HE Xinfu;RAN Huaichang;SUN Kai;CHEN Dongfeng(China Institute of Atomic Energy,Beijing 102413,China;Nuclear and Radiation Safety Center,Beijing 100082,China)

机构地区：[1]中国原子能科学研究院,北京102413 [2]生态环境部核与辐射安全中心,北京100082

出　　处：《核技术》2024年第6期19-25,共7页Nuclear Techniques

基　　金：中核集团领创项目(No.LC202309000301);国家自然科学基金(No.12375305);中国原子能科学研究院院长基金(No.YZ202312000720,No.YZ232505000901)资助。

摘　　要：辐照试样研究对评估材料性能具有重要意义。因其带有放射性,常规表征手段受到一定限制,而小角中子散射(Small-Angle Neutron Scattering,SANS)技术几乎不受γ、β等射线的影响,且制样简单。依托中国先进研究堆小角中子散射谱仪,研发了一台放射性样品测量装置,用于放射性试样内部纳米结构的测量分析。装置的屏蔽厚度利用蒙特卡罗模拟进行优化,结合自动换样和远程控制功能,提高了实验效率和安全性。利用该装置成功开展了A508-Ⅲ钢辐照监督试样的小角中子散射实验,结果表明低剂量长周期辐照对压力容器钢纳米结构影响较小。该装置和相关技术方法可用于放射性试样的纳米结构表征。[Background]The study of irradiated samples is of considerable importance.Owing to these samples being radioactive,the applicability of conventional characterization methods is limited.Because of the high sensitivity of 3He detectors to neutrons,the small-angle neutron scattering(SANS)technique is nearly unaffected by radiation such as gamma,beta rays,and sample preparation is simple.[Purpose]This study aims to develop a device for SANS measurement of nanostructures in radioactive samples.[Methods]The shielding thickness of the device was optimized through Monte Carlo simulations.Experimental efficiency and safety of the device were improved by combining remote-control functionality and automated sample switching among up to 12 samples loaded simultaneously.Finally,the device was used to carry out a SANS experiment for characterizing the radioactive A508-III steel sample.[Results]The optimized thickness of the lead shielding layer of the device is 7.5 cm,the corresponding maximum dose rate of the measurable radioactive sample is 1.4 mSv·h−1.The results of successful SANS experiment on a A508-III steel irradiation surveillance specimen indicate that low-dose,long-term irradiation has a minimal impact on the nanostructure of pressure vessel steel.[Conclusions]The device and associated technical methods can be applied for nanostructure characterization of radioactive samples.

关 键 词：小角中子散射 放射性试样 纳米结构 A508-Ⅲ钢 

分 类 号：TL99[核科学技术—核技术及应用]