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1.
金属材料中高能重离子辐照效应的理论描述   总被引:2,自引:0,他引:2  
简要介绍了高能重离子在金属材料中引起辐照效应的主要理论,特别是与电子能损引起的缺陷产生与演化、离子潜径迹形成、辐照相变以及各向异性塑性形变等效应相应的理论描述.  相似文献   

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与传统的铁素体钢相比,氧化物弥散强化(ODS) 的铁素体钢具有更优的耐高温和抗辐照性能,近年来成为先进核能装置重要的候选结构材料。在HIRFL 的扇聚焦型回旋加速器(SFC) 材料辐照终端,对一种氧化物弥散强化(ODS) 铁素体钢MA956 进行了高能Ne 离子辐照实验,旨在研究级联碰撞损伤和惰性气体原子注入条件下该材料力学性能的变化。利用辐照终端的能量衰减装置将SFC出口123.4 MeV的离子能量分解为介于38.5~121.0 MeV之间的30 个入射能量值,并通过双面辐照在厚度60 μm的样品中均匀产生了损伤。辐照剂量为9x1016 ions/cm2,在样品中的平均位移损伤为0.7 dpa,注入的Ne原子浓度为350 appm。辐照期间样品温度保持在440 ℃附近。对辐照前后的样品分别在室温和500 ℃下进行了小冲杆试验(Small-punchTest),获得了辐照前后样品的加载位移曲线,由此得到该辐照条件下样品的延性损失为18%~26%。通过扫描电子显微镜观察了断口形貌和厚度变化,估算了样品的等效断裂应变和断裂韧性。结果表明,MA956 钢经过高能Ne离子辐照后等延伸率减小,断裂韧性降低,样品发生了一定的脆化。透射电镜结果说明氧化物弥散相界面处微空洞的形成可能是导致脆化的原因。Oxide dispersion strengthened (ODS) ferritic steels have better high-temperature creep rupture strength and higher irradiation resistance than conventional ferritic steels, and show high prominence of application in advance nuclear reactors. Their stability under high-dose radiation conditions needs to be clarified. In the present study, a commercial ODS ferritic steel MA956 were irradiated with high 20Ne ions at a terminal chamber of the Sector-focused Cyclotron (SFC) at HIRFL (Heavy-ion Research Facility in Lanzhou). With the energy gradient degrader of the irradiation chamber, the primary energy (123.4 MeV) of the Ne-ion was dispersed into 30 different energies between 38.5~ 121.0 MeV, which resulted in a plateau distribution of lattice damage in the specimens. The specimens were irradiated from both sides so that the whole 60 m thickness was nearly uniformly damaged. The specimen temperature was maintained around 440 ℃ during the irradiation. The irradiation dose is about 9x1016 ions/cm2, corresponding to a damage level of 0.7 dpa and a Ne concentration of 350 appm. The specimens before and after irradiation were tested with the Small-punch Test technique, at room temperature and 500 ℃, respectively. The fracture morphology was observed by scanning electron microscopy.The results show that MA956 underwent some loss of ductility and fracture toughness after the irradiation with high-energy 20Ne ions. It may be ascribed to the formation of nano-scale cavities at the oxides/matrix interfacesin the ODS steel specimens under irradiation .  相似文献   

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聚合物材料的快重离子辐照效应   总被引:1,自引:0,他引:1  
简要介绍了快重离子辐照损伤的特点,通过与低电离辐射粒子辐照在聚合物材料中产生的效应的类比论述了快重离子辐照在聚合物材料中产生的效应及其研究现状 ,并结合快重离子辐照效应的应用展望了该领域未来的发展.The irradiation effects in polymers induced by swift heavy ions were reviewed in comparison with that induced by low ionization particles based on the characteristics of swift heavy ion irradiations. It is shown that bond breaking and cross linking, gas releasing, amorphization and carbonization of polymers depend strongly on the electronic energy loss. Besides special effects such as alkynes production, can be induced under swift heavy ion irradiation. The perspectives...  相似文献   

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利用高能离子模拟研究反应堆结构材料中的辐照效应   总被引:1,自引:0,他引:1  
简要介绍了载能粒子辐射损伤对反应堆结构材料性能的影响,阐述了载能粒子束特别是高能离子束开展模拟研究的优势,并举例说明了国内利用高能重离子模拟研究反应堆结构材料辐射效应取得的进展。实验结果和理论分析表明,载能离子特别是高能离子辐照非常适合用于模拟研究反应堆结构材料中由粒子辐射引起的材料微观结构和宏观性能变化,是模拟研究反应堆结构材料辐射效应的非常有效的手段。 Radiation damage in structural materials of fission/fusion reactors is mainly attributed to the evolution of intensive atom displacement damage induced by energetic particles ( n, α and/or fission fragments) and highrate helium doping by direct α particle bombardments and/or (n, α) reactions. It can cause severe degradation of reactor structural materials such as surface blistering, bulk void swelling, deformation, fatigue, embrittlement, stress erosion corrosion and so on that will significantly affect the operation safety of reactors. However, up to now, behavior of structural materials at the end of their service can hardly be fully tested in a real reactor. In the present paper, damage process in reactor structural materials is briefly introduced, then the advantages of energetic ion implantation/irradiation especially high-energy heavy ion irradiation are discussed, and several typical examples on simulation of radiation effects in reactor candidate structural materials using high-energy heavy ion irradiations are introduced. Experimental results and theoretical analysis suggested that irradiation with energetic particles especially high-energy heavy ions is a very useful technique for simulating the evolution of microstructures and macro-properties of reactor structural materials.  相似文献   

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快重离子在凝聚态物质中引起的效应——电子能损效应   总被引:1,自引:2,他引:1  
简述了快重离子在凝聚态物质中引起的效应——电子能损效应,主要包括缺陷的产生和潜径迹的形成、各向异性的塑性形变、由弹性碰撞产生的缺陷的部分退火、相变(非晶化),以及尝试性的理论解释.  相似文献   

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低活化的铁素体/马氏体钢是先进核能装置(如聚变堆)的重要候选结构材料。 在聚变堆实际工作环境下, 由于高温和高氦产生率引起的材料失效是这类材料面临的一个重要问题。 本项研究以兰州重离子加速器(HIRFL)提供的中能惰性气体离子束(20Ne, 122 MeV)作为模拟辐照条件, 借助透射电子显微镜, 研究了一种低活化的9Cr铁素体/马氏体钢(T92B)组织结构的变化和辐照肿胀。 实验结果表明, 高温下当材料中晶格原子的撞出损伤和惰性气体原子沉积浓度超过一定限值时, 材料内部形成高浓度的空洞, 并且空洞肿胀率显著依赖于辐照温度和剂量; 在马氏体板条界面及其它晶界处空洞趋于优先形成, 并且在晶界交汇处呈加速生长。 基于氦泡的形核生长与空洞肿胀的经典模型探讨了在不同辐照条件(He离子、 Ne离子、 Fe/He离子双束、 快中子、 Ni离子)下铁素体/马氏体钢中肿胀率数据的关联。Low activation Ferritic/Martensitic steels are a kind of important structural materials candidate to the application in advanced nuclear energy systems. Possible degradation of properties and even failure in the condition of high temperature and high helium production due to energetic neutron irradiation in a fusion reactor is a major concern with the application of this kind of materials. In the present work microstructural evolution in a 9Cr Ferritic/Martensitic steel (T92B) irradiated with 122 MeV 20Ne ions at temperatures between 0.3—0.5 Tm (Tm is the melting point of the material) was investigated with transmission electron microscopy. High concentration voids were observed in the specimens irradiated at high temperatures when the displacement damage dose and Ne concentration exceed a certain level. Preferential formation of voids at lath boundaries and other grain boundaries was found. The data of void swellings in 9Cr ferritic/martensitic steels irradiated in different conditions (such as with He ions, Ne ions, Fe/He dual beams, fast neutrons, Ni ions etc.) were compiled and analyzed based on a classic model of helium bubble formation, and bubble to void transition.  相似文献   

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本文系统地评述了中能重离子在铁氧体材料小辐照效应的国际国内研究概况.并指出了利用兰州重离子研究装置(HIRFL)可进一步开展的工作.This paper gives a systemic review on the recent progress in the study of irradiation effects in ferrite induced by energetic heavy ions, and also gives a suggestion thatsome experiments in this field can be carried out further by Heavy Ion Reseach Facility ofLanzhou(HIRFL ).  相似文献   

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基于荷能离子与固体相互作用特点,提出了一种新的制备光致发光材料的方法-- 高能重离子辐照. 用这种方法研究了SiO2薄膜的光致发光特性,发现高能84K r和40Ar离子辐照可在注碳SiO2薄膜样品中产生强的蓝-紫光发射带,掺杂碳增强了辐照样品的发光特性.  相似文献   

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用傅立叶变换红外光(FTIR)谱仪和紫外/可见光(UV/VIS)谱仪研究了2.1GeVKr离子在聚碳酸酯(PC)膜中产生的效应.研究结果表明,在高能Kr离子辐照下,PC膜中发生了断键、断链和键的重组,炔基的出现是键的断裂和重组的结果.这些效应与辐照剂量和电子能损有关.辐照也使PC膜中发生了从氢化非晶态碳向非晶态碳的转变,在UV/VIS中,波长为380,450和500nm处的相对吸光度随能量沉积密度的增加近似按线性变化.  相似文献   

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概述了利用穆斯堡尔效应开展的固体材料快重离子辐照效应研究的部分结果 ,并对建立在兰州重离子加速器 (HIRFL)上的在束穆斯堡尔谱学研究装置及其应用作了简要的介绍.Mssbauer spectroscopy study of irradiation effects induced by swift heavy ions in solid materials were briefly presented.Amorphization phenomenon of yttrium iron garnet irradiated by 1 GeV Ar ions has been investigated. For the first time, the nearly complete amorphous state was observed. Stainless steel 316L samples were irradiated with 54 MeV C ions and phase transformation of the samples was observed. HT 9 ferrite steel was irradiated with 510 MeV C ions. Its phase...  相似文献   

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简要介绍了快重离子在固体材料中强电子激发效应的基本特点、研究现状和在HIRFL上获得的部分实验结果,并对今后的研究工作进行了展望。In this paper the outline of intense electronic excitation effects in solid materials induced by swift heavy ions and international research status were briefly reviewed. Few examples of experimental results obtained on HIRFL were presented. And also the developing tendency in the field was looked into the future.  相似文献   

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用高能(500MeV)Ne离子束对GaAs和InP进行了辐照,用MonteCarlo模拟、正电子湮没谱学以及红外光谱研究了辐照产生的缺陷特性.结果表明,在未辐照的样品中存在单空位,经辐照后,可在样品中产生单空位;当剂量较大时,还会形成双空位甚至尺寸较大的空洞.红外光谱测量发现,在辐照后的GaAs样品中有非晶区形成.此外,辐照在样品中还产生了反位缺陷GaAs和InP以及受主杂质ZnIn.对经1014ions/cm2剂量辐照的InP进行了光学实验,在辐照后的InP材料中发现了亚稳态中心. Both GaAs and InP were irradiated by high energy (500 MeV) Ne ions. The Monte Carlo simulation, positron annihilation and IR spectroscopy were used to study the radiation induced defects. The result showed that monovacancies existed in as grown samples, but more monovacancies were introduced, after Ne ions irradiation, and with increasing radiation dose, divacancies were formed, and eventually large voids were observed. The IR measurement for irradiated GaAs samples confirmed the...  相似文献   

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快重离子引起的塑性形变现象   总被引:2,自引:2,他引:0  
非晶材料在快重离子轰击下显示了奇异的各向异性的塑性形变 ,这是电子能损所引起的宏观可见的剧烈的原子重排 .这个效应不能发生在具有晶态结构的材料中 ,但发生于所有的非晶材料中 .这一宏观现象隐含了寻找原子尺度上电子激发转换成原子位移的潜在线索 ,因而受到广泛的关注 .在回顾了现象发现的历史之后 ,综述了离子束引起的塑性形变的基本规律、最新结果、实验方法和技术新的进展 ,最后讨论了相关的物理机制和唯象模型. A very peculiar effect occurring when an amorphous material is irradiated with swift heavy ion is the giant plastic deformation phenomenon discovered in the eighties by Klaumunzer[DD(-8/9]¨ It is macroscopically visible atomic rearrangements induced by electronic energy loss. This effect occurs only in truly amorphous solids and can not occur in a crystalline material. This phenomenon gives rise to a wide ranging and lasting research in the field of the interaction of swift heavy...  相似文献   

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