CARR中子深度剖面分析系统设计
|
摘要
中子深度剖面分析(Neutron Depth Profiling,NDP)是一种高灵敏、高分辨测量材料近表面深度分布信息的无损检测技术,利用中国先进研究堆(China Advanced Research Reactor,CARR)冷中子束建立了一套中子深度剖面分析系统,该系统真空度优于其他NDP设备,可达到3.4×10-5 Pa。冷中子注量率高是其另一大优势,CARR在15 MW功率下运行时,用金活化法测得中子导管末端的中子注量率约为4.8×108cm-2?s-1。此外,该系统一次性可以测量6个样品,简单易行。通过测试美国国家标准与技术研究院(National Institute of Standards and Technology,NIST)标准物质SRM-2137评价CARR-NDP系统的性能,测量结果与参考值具有较好的一致性,验证了CARR-NDP系统的可行性。
[Background] Neutron depth profiling(NDP) is a non-destructive near-surface analysis technique and it is widely used in characterization of polymers, semiconductors, alloys, lithium ion battery materials, photoelectric materials and many other materials. [Purpose] This study aims is to develop NDP system to obtain the depth profiles of several crucial light nuclides(e.g.,6 Li and10 B) in nearly any substrate. [Methods] Based on the cold neutron beam of China advanced research reactor(CARR), a NDP system was developed with vacuum reached 3.4 × 10-5 Pa and neutron flux rate of 4.8 × 108 cm-2?s-1. The standard reference material(SRM-2137) sample was used to test the performance of this NDP system. The measured α-particle spectrum was calculated by the inversion iterative algorithm to obtain the depth profiles of crucial elements. [Results] The experimental results show that the simulation results of SRM-2137 agree well with the experimental results. The maximum error is less than 4% at each layer of5 nm thickness. The peak depth is very close to the reference value(188 nm). The depth accuracy is 0.53%.[Conclusions] Established CARR-NDP system and relevant experiments and data analysis techniques have been verified. The system will be further applied to investigating the lithium ion batteries, multilayer films and hightemperature alloys, etc.
[Background] Neutron depth profiling(NDP) is a non-destructive near-surface analysis technique and it is widely used in characterization of polymers, semiconductors, alloys, lithium ion battery materials, photoelectric materials and many other materials. [Purpose] This study aims is to develop NDP system to obtain the depth profiles of several crucial light nuclides(e.g.,6 Li and10 B) in nearly any substrate. [Methods] Based on the cold neutron beam of China advanced research reactor(CARR), a NDP system was developed with vacuum reached 3.4 × 10-5 Pa and neutron flux rate of 4.8 × 108 cm-2?s-1. The standard reference material(SRM-2137) sample was used to test the performance of this NDP system. The measured α-particle spectrum was calculated by the inversion iterative algorithm to obtain the depth profiles of crucial elements. [Results] The experimental results show that the simulation results of SRM-2137 agree well with the experimental results. The maximum error is less than 4% at each layer of5 nm thickness. The peak depth is very close to the reference value(188 nm). The depth accuracy is 0.53%.[Conclusions] Established CARR-NDP system and relevant experiments and data analysis techniques have been verified. The system will be further applied to investigating the lithium ion batteries, multilayer films and hightemperature alloys, etc.
引文
1 Ziegler J F.Technique for determining concentration profiles of boron impurities in substrates[J].Journal of Applied Physics,1972,43(9):3809.
2 Ryssel H,Glawischnig H.Ion implantation:equipment and techniques[M].Ion Implantation:Equipment and Techniques,1983.
3 Park B G,Sun G M,Choi H D.Development of cold neutron depth profiling system at HANARO[J].Nuclear Instruments and Methods in Physics Research Section A:Accelerators,Spectrometers,Detectors and Associated Equipment,2014,752:20-26.
4 Li R D,Yang X,Wang G B,et al.Development of neutron depth profiling at CMRR[J].Nuclear Instruments and Methods in Physics Research Section A:Accelerators,Spectrometers,Detectors and Associated Equipment,2015,788:1-4.
5姚永刚,肖才锦,金象春,等.CARR堆冷中子瞬发伽玛活化分析系统及实验研究[J].同位素,2018,31(06):362-369.YAO Yonggang,XIAO Caijin,JIN Xiangchun,et al.CARR reactor neutron prompt gamma activation analysis system and experimental study[J].Isotopics,2018,31(06):362-369.
6 Kenanünlü,Wehring B W.Neutron depth profiling at the University of Texas[J].Nuclear Instruments&Methods in Physics Research Section A(Accelerators,Spectrometers,Detectors and Associated Equipment),1994,353(1-3):402-405.
7余小玲,冯全科,田健,等.中国先进研究堆(CARR)冷中子源装置设计[J].低温工程,2016,(05):48-52.YU Xiaoling,FENG Quanke,TIAN Jian,et al.Design of cold neutron source device for China Advanced Research Reactor(CARR)[J].Cryogenic Engineering,2016,(05):48-52.
8丁大钊,叶春堂,赵志祥.中子物理学:原理、方法与应用[M].北京:原子能出版社,2001.DING Dazhao,YE Chuntang,ZHAO Zhixiang.Neutron physics:principles,methods and applications[M].Beijing:Atomic Energy Press,2001.
9?etiner S M,ünlüK,Downing R G.Development and applications of time-of-flight neutron depth profiling(TOF-NDP)[J].Journal of Radioanalytical&Nuclear Chemistry,2008,276(3):623-630.
10 Ziegler J F,Ziegler M D,Biersack J P.SRIM-the stopping and range of ions in matter(2010)[J].Nuclear Instruments&Methods in Physics Research B,2008,268(11):1818-1823.
11杨鑫,李润东,刘汉刚,等.基于概率迭代的NDP反演方法[J].计算物理,2012,29(6):891-900.YANG Xin,LI Rundong,LIU Hangang,et al.NDPinversion method based on probability iteration[J].Chinese Journal of Computational Physics,2012,29(6):891-900.
12 Shi C,Xiao C J,Yao Y G,et al.Inverse iteration algorithm for neutron depth profiling[J].Journal of Radioanalytical and Nuclear Chemistry,2018,317(1):81-85.
2 Ryssel H,Glawischnig H.Ion implantation:equipment and techniques[M].Ion Implantation:Equipment and Techniques,1983.
3 Park B G,Sun G M,Choi H D.Development of cold neutron depth profiling system at HANARO[J].Nuclear Instruments and Methods in Physics Research Section A:Accelerators,Spectrometers,Detectors and Associated Equipment,2014,752:20-26.
4 Li R D,Yang X,Wang G B,et al.Development of neutron depth profiling at CMRR[J].Nuclear Instruments and Methods in Physics Research Section A:Accelerators,Spectrometers,Detectors and Associated Equipment,2015,788:1-4.
5姚永刚,肖才锦,金象春,等.CARR堆冷中子瞬发伽玛活化分析系统及实验研究[J].同位素,2018,31(06):362-369.YAO Yonggang,XIAO Caijin,JIN Xiangchun,et al.CARR reactor neutron prompt gamma activation analysis system and experimental study[J].Isotopics,2018,31(06):362-369.
6 Kenanünlü,Wehring B W.Neutron depth profiling at the University of Texas[J].Nuclear Instruments&Methods in Physics Research Section A(Accelerators,Spectrometers,Detectors and Associated Equipment),1994,353(1-3):402-405.
7余小玲,冯全科,田健,等.中国先进研究堆(CARR)冷中子源装置设计[J].低温工程,2016,(05):48-52.YU Xiaoling,FENG Quanke,TIAN Jian,et al.Design of cold neutron source device for China Advanced Research Reactor(CARR)[J].Cryogenic Engineering,2016,(05):48-52.
8丁大钊,叶春堂,赵志祥.中子物理学:原理、方法与应用[M].北京:原子能出版社,2001.DING Dazhao,YE Chuntang,ZHAO Zhixiang.Neutron physics:principles,methods and applications[M].Beijing:Atomic Energy Press,2001.
9?etiner S M,ünlüK,Downing R G.Development and applications of time-of-flight neutron depth profiling(TOF-NDP)[J].Journal of Radioanalytical&Nuclear Chemistry,2008,276(3):623-630.
10 Ziegler J F,Ziegler M D,Biersack J P.SRIM-the stopping and range of ions in matter(2010)[J].Nuclear Instruments&Methods in Physics Research B,2008,268(11):1818-1823.
11杨鑫,李润东,刘汉刚,等.基于概率迭代的NDP反演方法[J].计算物理,2012,29(6):891-900.YANG Xin,LI Rundong,LIU Hangang,et al.NDPinversion method based on probability iteration[J].Chinese Journal of Computational Physics,2012,29(6):891-900.
12 Shi C,Xiao C J,Yao Y G,et al.Inverse iteration algorithm for neutron depth profiling[J].Journal of Radioanalytical and Nuclear Chemistry,2018,317(1):81-85.