用沟道离子注入法研制稀土硅化物

用沟道离子注入法生成的稀土硅化物经背散射沟道分析,电镜分析和Ｘ射线衍射测试表明,它具有很好的结晶品质和很高的相稳定性。     

面沟道粒子的空间分布和动量分布

薄单晶的透射实验表明,当粒子的横向能量比较小时,它的轨迹总是位于沟道内部,且表现出明显的周期行为:背散射实验揭示了表面附近的粒子轨道也具有同样的振荡特征。透射和背散射实验表现出来的这种性质,说明了粒子的空间分布和动量分布与粒子进入晶体的深度有关;事实上,几乎所有沟道现象都可用深度相关的空间分布和动量分布来解释,因此,如何计算沟道粒子的空间分布和动量分布成了人们十分关心的问题。     

低能离子溅射引起表面损伤的研究

本文应用背散射沟道技术研究了低能离子轰击不同晶向表面所引起的晶格损伤与离子能量、剂量的关系,讨论了损伤形成的动力学过程。     

用时间分辨反射率技术研究硅的固相外延

用时间分辨反射率技术实时测量了Ｓｉ＋、Ａｓ＋注入单晶硅的固相外延生长速率和外延层厚度，并与背散射沟道方法测得的非晶层厚度进行了比较。介绍了测量原理，分析了实验结果．     

背散射模拟谱与实验谱的显示软件的应用

材料科学的研究在国防事业、工农业生产和国计民生的各个方面有着重要的意义。加速器离子束分析如背散射分析(RBS),沟道分析(Channeling)、核反应分析(NRA)及质子荧光分析(PIXE)等以其不破坏样品,分析灵敏度高,迅速可靠等特点在材料科学研究领域占有独特的优势。它适于研究半导体、超导和各种金属材料。特别是背散射分析非常适于分析材料表面几百纳米薄层内的原子组分、深度分布及不同材料之间的界面反应等,这些分析为研究各种材料的特性,提高它们的品质,研制各种新型特殊材料提供了可靠的理论与实验的依据,为了提高背散射分析的精度,更迅速地处理实验数据,同时也     

低速高电荷态重离子在GaN单晶中引起的辐照损伤研究

利用Rutherford沟道背散射分析研究了低速高电荷态重离子(Xe26 )在氮化镓(GaN)晶体中辐照损伤的产生对剂量的依赖关系,比较了垂直照射和60°倾斜照射的差异.基于"库仑爆炸"模型对结果进行了解释.     

25keV As^＋大倾斜角注入的损伤分析

通过２５ｋｅＶ的Ａｓ＋注入硅中．用背散射沟道分析技术和椭圆偏振光测量技术分析了在倾斜角分别为７°、１５°、３０°、４５°和６０°时的损伤分布，揭示了大倾斜角注入在注入能量较低时的一些物理现象．     

用背散射方法分析硅中注入砷的深度分布

用离子注入方法能快速地将一种杂质元素射入到半导体材料中,而杂质元素在材料中的浓度随深度的分布直接影响了材料的性能,因此准确测定它们是十分必要的。我们用背散射分析法分析了注入砷的硅样品。 1.实验方法和数据处理 样品是电阻率为7～15Ω·cm、〈111〉晶向的p型单晶硅。为避免沟道,约倾斜7°注入,经严格清洗后在氮气保护下,在不同退火条件下恒温退火。背散射实验工作是在原子能所静电加速器上进行的,选用     

离子束合成法形成的Si／CoSi2／Si／SiO2／Si（100）结构

用离子束合成法先后在Si(100)衬底中形成了连续的SiO_2及CoSi_2埋层,从而形成了复合的Si/CoSi_2/Si/SiO_2/Si(100)结构。卢瑟福背散射、沟道技术及用扫描电镜所作的电子通道花样被用来对这一结构形成的各个阶段进行分析。这一结构可望用于今后新型的微电子器件、光电器件及三维集成电路等。     

硫对注入YSZ单晶的金属铂在退火过程中结晶的影响

秀卢瑟福背散射－沟道技术（ＲＢＳ－Ｃ）和Ｘ射线衍射技术（ＸＲＤ）研究了Ｐｔ和注入ＹＳＺ（Ｙ２Ｏ３稳定的ＺｒＯ２）后产生的损伤和退火过程中损伤的恢复及注入Ｐｔ的晶化，ＲＢＳ－Ｃ分析表明ＹＳＺ室温下的存在较强自退火效应，ＸＲＤ分析结果示出硫以铂的晶化产生很大影响。     

基于工业CT的工件缺陷识别方法

工业CT是一种有效的工件缺陷识别的方法,代表着无损检测技术的发展方向.首先概述工业CT技术在工件缺陷识别中的应用,并把其他和其他常用方法进行了简单比较;接着从工件缺陷识别的流程入手,对每个步骤都从处理思路和处理方法方面作了阐述;然后对一些在工件缺陷识别方面很有潜力的算法(Level set和Gabor小波)进行了介绍和分析;最后对工业CT在工件缺陷识别方面的应用前景进行了展望.     

PROGRESS IN ION BEAM ANALYSIS AT FUDAN UNIVERSITY

Progres in ion beam analysis at Fudan University in the recent years is briefly reviewed. Presented as examples of the research activities performed in this field are the following projects: (1) Nuclear potential resonance scattering of 6.25 MeV and 4.25 MeV helium ions for simultaneous compositional analysis of carbon and oxygen in a Mylar, a SnInO, and some other film samples: (2) Determination of stoichiometry of a high-temperature superconducting Y-Ba-Cu-O sample by backscattering of 8.8 MeV helium ions; (3) Backscattering and channeling analysis of multilayered structures periodically consisting of layers of pure Si and alternate layers of Ge and Si, grown on (100) Si substrates by molecular beam epitaxy: (4) Studies of surface structure of Al(100) by the use of MeV ions backscattering and channeling surface peak: and (5) MeV ion microbeam analysis and the use of PIXE method in DNA study. etc.     

微束背散射分析元素微区分布的研究

微束背散射分析元素微区分布的分析方法使上海原子核研究所的质子微探针能在微区内综合使用质子激发Ｘ射线荧光和背散射等多种核效应，为样品由轻元素到重元素的全面无损、双微（微区、微量）分析提供了依据。应用该方法还测量了Ｓｉ３Ｎ４／ＳｉＣ复合陶瓷材料，证明了该分析方法的可靠性。     

反应堆压力容器内壁面异种金属焊接缺陷的修复及力学评价

某核电站反应堆压力容器(RPV)制造期间超声检测（UT）显示,顶盖法兰内壁面堆焊层熔合线附近出现大范围连续焊接缺陷,环向跨度大于8°,造成大范围低合金钢母材减薄。针对上述缺陷的产生开展了根本原因分析,结合技术现状给出补焊不锈钢的修复方案并展开详细的力学评价,从应力、疲劳和密封角度分析该缺陷对RPV性能的影响,论证了该修复方案的可行性。补焊不锈钢方案已得到工程应用,可为工程上类似问题的处理提供借鉴。     

Instrumental Design and Verification of a Nondestructive Testing with Neutron Backscattering for Boron-based Material Characteristics

The in-situ nondestructive testing (NDT) instrument using neutron backscattering for boron-based materials was developed successfully in this work. The capability verification of confirming qualitatively the integrity of the boron-based material as neutron absorber and characterizing quantitatively the gap defect size was demonstrated herein. For extending the technique at the fast traverse mode, a derived relationship between the defect size and output signal considering the effects of scanning speed and time constant was presented in this work for data interpretation. We also performed an experimental sensitivity analysis as a function of operation parameters. Through a comparison of the increase in output counting rate current between calculation and measurement, the deviation of the theoretical prediction at the fast traverse mode was within ±30%.     

Morphology of the implantation induced disorder in GaAs

Disorder is introduced into GaAs by implantation of ³⁰Si⁺ ions, using a very wide range of ion doses, and studied by Raman scattering (RS) and Rutherford backscattering and ion channeling (RBS). A comparative analysis of mechanisms influencing RS and RBS signals has been made. This analysis revealed that, due to different sensitivity of each method to various defect structures, it is possible to distinguish several different types of implantation induced disorder. RS results indicate that a second type of amorphous structure, having medium-range order, grows at the expense of the continuous-random-network structure, even at doses beyond the threshold for complete amorphization.     

影响γ反散射光子计数因素的分析

推导了一般情况下反散射光子计数的理论公式,通过简化物理模型分析了影响反散射光子计数的各种因素,并且计算得到了不同几何条件下和不同物质的反散射光子计数的差异。     

Ion-beam induced effects in α-Al2O3 at 15 K

In order to study the primary effects of ion-beam induced damage formation in sapphire, implantation and subsequent damage analysis by Rutherford backscattering spectrometry (RBS) in channelling configuration were performed at 15 K without change of the sample temperature. We used 80 keV Na, 150 keV K and 150 keV Ar to investigate the damage accumulation with increasing ion fluence. During the RBS measurement with 1.4 MeV He ions at 15 K, defect annealing was observed. From the measured channelling spectra, defect profiles were calculated using the computer code DICADA. These profiles are narrower and distinctly lower than those calculated by SRIM2003, especially below the surface. This suggests an enhanced recombination of defects within this area. The damage concentration at the peak maximum is analysed as a function of ion fluence or rather displacements per atom. The model that was applied contains two different types of defects, namely point defects and clusters and takes into account the defect annealing under the He beam. For both defect profiles and damage accumulation, no significant influence of the implanted ion species was observed.     

基于人工神经网络的压水堆燃料破损状态监测

为提升对核反应堆燃料棒包壳破损的预测能力,建立两个串联的人工神经网络分别判断燃料棒包壳是否破损以及破损程度。通过改变沾污铀质量、增加数据扰动、改变运行功率和使用更少的特征核素进行训练,对用于判断是否破损的神经网络模型和判断破损等级的神经网络进行了性能测试和分析。在沾污铀质量小于0.5 g、数据扰动在30%以内、单棒功率在77 kW到120 kW之间的条件下,第1个人工神经网络能较好地判断出是否破损。第2个神经网络,对于考虑的5种破损程度,判断的精确性较高。与传统的碘同位素比值法相比,神经网络方法响应更快,精度更高。结果表明,人工神经网络可用于预测反应堆燃料包壳是否发生破损以及破损程度。