离子束分析进展

1983年在美国亚里桑那州州立大学召开了第六届国际离子束分析会议。这次会议的侧重方向是低能离子散射。近年来,由于超高真空技术、高速计算机、飞行时间方法、离子源等技术的发展和应用,散射截面、射程、阻止本领等各种基本参数的精确化,促进了低能离子散射技术的发展,使它成为表面结构分析中的重要手段。必须指出,上述多方面技术的进步所产生的影响,不仅仅局限于低能离子散射,而是遍及离子束分析的整个领域。     

离子束分析进展——介绍第六届国际离子束分析会议

第六届国际离子束分析会议于1983年5月23日至27日在美国凤凰城附近的亚里桑那州州立大学召开,由该校物理系主办。主办单位必须提出一个“这次会议的主导方向”或“侧重方向”。 这次会议的主办单位提出的侧重方向是:低能离子散射。必须指出,在离子束分析领域中的“低能、中能、高能”与原子核物理或粒子物理中相应的概念大不相同。在这里,低能是指离子的能量低于约10keV,中能是指10～1000keV,高能则是指MeV量级的离子束。     

离子束分析技术在抗核加固研究中的应用

本文介绍了核辐射使电子元器件失效的机制以及离子束分析技术在抗核加固研究中的若干应用。     

穆斯堡尔谱技术在考古学中的应用

本文评述了穆斯堡尔谱技术在考古学中应用的最新进展,并展望了它的发展方向。     

离子束生物技术及其在玉米育种中的应用

离子束作为一种新兴诱变源,已广泛应用于各种农作物的诱变育种。离子束生物技术为玉米品种的改良和种质资源的创新开辟了一条新的道路,推动了玉米育种事业的长足发展。本文阐述了离子束的特点、诱变机理以及在玉米育种中的应用。     

中国科学院物理研究所的离子束分析及离子注入改性研究

介绍了中国科学院物理研究所离子束研究室的主要设备、分析方法、离子注入材料改性研究以及近年来在半导体材料、高Ｔｃ超导材料、环保等领域中的研究工作。     

固体核径迹探测器在地质学和考古学中的应用

本文介绍了裂变径迹年龄测定方法及其在地质年代学、考古学、古人类学、第四纪地质学、测定构造活动区上升速度、测定海底扩张速度等方面的应用。从固体核径迹的热效应来看,可以将裂变径迹年龄区分为三种类型：生成型年龄、冷却型年龄和混合型年龄。裂变径迹年龄的应用就是建立在对各种不同类型的裂变径迹年龄正确理解的基础上。     

双等源强流离子束分析

目前所使用的各种离子源,还不能产生具有完全单一荷质比的离子,所以,离子源所提供的离子束是包含多种离子组态的混合束。因此,要把离子加速到高能,就涉及到一个多动量离子束加速系统。在由电磁场(电磁组件)构成的强流带电粒子加速系统中,多动量离子束的加速和聚焦会产生许多缺陷与困难。在强流加速器中,提高所需离子的加速效率,减轻加速器的总负荷,是一个很重要的     

离子束材料改性应用中的新进展

着重分析了离子注入提高离子束加工效益的途径,离子束工业生产发展现状和未来离子束技术在国民经济中的重要作用。     

轴对称离子束和带形离子束的相互转换

本文讨论轴对称离子束与带形离子束的相互转换问题,并以偏转磁铁为例子,说明其应用。     

First results obtained using the CENBG nanobeam line: Performances and applications

A high resolution focused beam line has been recently installed on the AIFIRA (“Applications Interdisciplinaires des Faisceaux d’Ions en Région Aquitaine”) facility at CENBG. This nanobeam line, based on a doublet-triplet configuration of Oxford Microbeam Ltd. OM-50™ quadrupoles, offers the opportunity to focus protons, deuterons and alpha particles in the MeV energy range to a sub-micrometer beam spot. The beam optics design has been studied in detail and optimized using detailed ray-tracing simulations and the full mechanical design of the beam line was reported in the Debrecen ICNMTA conference in 2008. During the last two years, the lenses have been carefully aligned and the target chamber has been fully equipped with particle and X-ray detectors, microscopes and precise positioning stages. The beam line is now operational and has been used for its first applications to ion beam analysis. Interestingly, this set-up turned out to be a very versatile tool for a wide range of applications. Indeed, even if it was not intended during the design phase, the ion optics configuration offers the opportunity to work either with a high current microbeam (using the triplet only) or with a lower current beam presenting a sub-micrometer resolution (using the doublet-triplet configuration).The performances of the CENBG nanobeam line are presented for both configurations. Quantitative data concerning the beam lateral resolutions at different beam currents are provided. Finally, the first results obtained for different types of application are shown, including nuclear reaction analysis at the micrometer scale and the first results on biological samples.     

Mn DEPLETION IN THE SURFACE LAYER OF STAINLESS STEEL 304 LN AT THE TEMPERATURE 1200 K

The Mn component of stainless steel 304 LN has been found to be severely depleted in the surface layer during heating at the temperature 1200 K. The surface concentrations of Mn were reduced by about 2- 3 orders of magnitude in comparison with the bulk value, as was revealed by a secondary ion mass spectroscopy (SIMS) system. And the Mn concentration gradient in the surface layer was examined, too, by SIMS. Massive preferential losses of Mn have been determined by using the catcher technique and proton induced X- ray emission (PIXE). A theoretical model has been proposed for calculating the surface concentration changes for a component in an alloy under heating. A comparison shows a good agreement between the calculation and experimental results from SIMS and catcher technique.     

THE PEKING UNIVERSITY MULTI—APPLICATION ION BEAM ANALYSIS SYSTEM

A multi-application ion beam analysis system and some research projects performed at this system are described. The lifetime of the RF ion source for He~- is discussed.     

IS-A离子源的实验研究和初步应用

为加热HT-6M托卡马克等离子体而研制的IS-A十厘米双潘宁离子源具有强流、大功率。高质子比等特点。经过进一步的发展,该源可以引出多种气体离子束,以满足不同实验的需要。本文详细地研究了几何结构和运行条件对源等离子体的影响。报道了该离子源在其它领域中的初步应用。     

Characterisation and corrosion resistance of TiN-Ni nanocomposite coatings using RBS and NRA

Nanocomposite TiN-Ni coatings were produced by a duplex treatment on Ti-6Al-4V substrates. The procedure consisted of plasma nitriding of the substrate followed by deposition of a TiN-Ni layer by sputtering a composite Ti-Ni target with 1.2 keV Ar⁺ ions. The growing film was bombarded during deposition by a mixture of 50 eV Ar⁺-N²⁺-N⁺ ions. The temperature as well as the Ni- and the N-content of the coatings varied in order to obtain the optimum structural and mechanical properties. The surface morphology of the coatings was examined by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The results showed that Ni appears as an amorphous phase around the TiN crystallites. The thickness and the composition of the coatings were investigated by Rutherford Backscattering Spectrometry (RBS) using deuterons as projectiles. The nitrogen depth distribution in the coatings was determined by Nuclear Reaction Analysis (NRA) using ¹⁴N(d, α) and ¹⁴N(d, p) nuclear reactions. The corrosion resistance of the nitrided and non-nitrided coatings in aggressive environment (NaCl 3% solution at RT) was investigated using electrochemical techniques (potentiodynamic polarisation and cyclic voltammetry). It was found that nanocomposite coatings are stable and do not influence the corrosion resistance of the Ti-alloy substrate. The nitrided coatings exhibited higher wear and corrosion resistance related with their Ni-content.     

High-Energy PIXE using 68 MeV protons

The elemental composition of realistic thick samples has been measured with PIXE by 68 MeV protons. Heavy elements can be well detected much deeper below the surface, than with other methods. Measurements on objets d'art are presented. Large and complicated objects can be measured easily.     

铬,钽离子束表面冶金合金的抗腐蚀机制

根据离子束表面冶金的特点，从合金成分、结构、缺陷、元素性质以及表面污染等方面系统地讨论了Ｃｒ、Ｔａ元素加入对金属腐蚀行为的影响。在此基础上，提出它们抑制腐蚀的综合模式，较好地解释了这类表面合金抗腐蚀的机制。     

一种简易的电荷堆积排除器

本文介绍一种应用于离子束分析实验的电荷堆积排除器,它可以有效地消除入射束流在绝缘体样品上产生的电荷堆积。本方法结构简单、易于制作。文中给出了采用这种电荷堆积排除器测得的瓷碟上白釉的背散射能谱。     

Proton elastic scattering differential cross-section measurements of Sc

In the present study the differential cross sections of the ⁴⁵Sc(p,p)⁴⁵Sc reaction were measured. Two independent experiments were performed. At first a sandwiched thin ScBr₃ target was used for beam energies E_LAB = 2300-5500 keV (in steps of 25 and 50 keV) and for detector angles 140°, 160°, and 170°. Secondly a thick Sc₂O₃ sample was formed and irradiated for E_LAB = 3100-5500 keV with a detector placed at 140°, to validate the results of the first measurement.