电子束加工技术及其在表面工程中的应用

分析了电子束加工的原理、特点及其应用类型，介绍了电子束加工技术在表面工程中的应用。     

电子束熔炼Mo合金提纯效果分析

主要讨论和对比了不同电子束精炼方式对Mo合金提纯效果的影响。实验结果表明,垂熔烧结棒经电子束悬浮区域熔炼后,其杂质元素总和不大于150ug/g,而两次电子束熔炼原料棒经电子束悬浮区域熔炼后,其杂质元素总合不大于50ug/g。     

电子束毛化冷板散热性能优化设计

电子束“毛化”技术是一种新型表面处理技术。将电子束表面毛化技术应用于液冷冷板,其毛化阵列结构能有效提高冷板流道表面散热面积,同时加强流体的扰动,在提高冷板散热性能上有较大潜力。文中以铝合金电子束毛化冷板为研究对象,通过实验测试和数值仿真研究不同毛化柱结构参数和阵列间距对散热的影响。研究结果表明,电子束毛化冷板在高热流密度、小流量工况下可将散热能力提升10% 以上。该实验和仿真结果可用于电子束毛化冷板优化设计。     

用扫描电子显微镜改装的电子束曝光机

我们改装了日立Ｓ５３０型扫描电子显微镜，使之具有外控电子束偏转功能，通过计算机控制实现电子束曝光。根据电子束制备图形的要求，我们编写了专用软件，实现计算机辅助计算，数据处理与数模转换输出。使用ＰＭＭＡ电子束抗蚀剂，在该系统上获得０．１微米的线分辨率。     

电子束焊接

电子束焊机始于60年代，至今已研制生产出不同类型和功能的电子柬焊机，能为国内市场提供小功率的电子束焊机。     

大厚度紫铜电子束焊接的研究

通过对大熔深电子束紫铜焊缝的研究，采用横枪电子束焊接方法在含气量较高的试件上获得２５ｍｍ熔深的焊缝，并消除了气孔、裂纹等缺陷。讨论电子束倾斜入射工件时，倾斜角度对焊缝质量的影响。     

高压电子束焊机中电子束发生系统的设计计算

电子束焊接是通过阴极加热发射的电子，经高压电场加速后，获得极高的动能，加速后的电子经过磁透镜聚焦而形成能量密度极高的电子柬来轰击工件表面。电子束发生系统的设计直接影响电子枪的性能、发射能力以及电子柬的轨迹，进而影响到整个电子柬焊机的焊接性能。     

电子束辐照对GaN基蓝光LED特性参数影响

本文利用能量为1-3MeV、最大功率为90KW的工业用地那米型电子加速器产生的低能电子束对GaN基蓝光LED进行了电子束辐照实验,对比了辐照前后的LED颜色参数,光度参数的变化,同时对实验结果进行分析和讨论。结果表明,在电子束辐照下,LED的主波长发生了漂移,色纯度提高,光通量、光效都有所降低,并且发现电子束辐照会引起LED芯片量子阱中的原子位移,非复合型复合,降低少子寿命。     

高真空电子束焊机新型控制系统的设计

介绍新型真空电子束焊机控制系统的技术要求，利用计算机控制技术和PLC技术分别实现了电子束焊机的参数控制和主机系统的控制，并根据设备的技术要求和工艺需要设计了计算机通信软件和PLC应用软件，设备运行表明：设计的硬件和软件工作可靠，符合电子束焊接工艺的需要。     

电子束炉进料系统的设计

电子束炉是研究和生产高纯材料必不可少的设备，相对于其它熔炼炉有很多优点。近年来我国在电子束炉方面的研究很少，主要依靠进口。我院根据科研和生产需要设计开发了新型大功率电子束炉，已成功推广应用。本文简述了此新型电子束炉的主要结构和工作原理，并重点对其中的进料系统的设计开发过程进行总结，详细介绍了进料系统的各组成部分的结构及其特点。     

Thermal sensitive paper as a diagnostic for intense relativistic electron beam dynamics

Thermal sensitive paper has been used as a diagnostic for an intense relativistic electron beam propagating in a rippled magnetic field. The E(r)xB(z) rotation of the beam has been measured from the exposed pattern on the thermal paper and used to calculate the electrostatic field of the beam E(r), and the corresponding values of electron density and beam current. Exposed strips of thermal paper show longitudinal modulation of the radial electron velocity with a period corresponding to that of a rippled magnetic field; modulation of the radial electron velocity at the cyclotron frequency has also been observed.     

Resolution in low voltage scanning electron microscopy

As the energy of an electron beam is reduced, the range falls and the secondary electron yield rises. A low voltage scanning electron microscope can therefore, in principle, examine without damage or charging samples such as insulators, dielectrics or beam sensitive materials. This paper investigates the way in which the choice of beam energy affects the spatial resolution of a secondary electron image. It is shown that for samples which are thin compared to the electron range, the edge resolution and contrast in the image improve with increasing beam energy. In samples that are thicker than the electron range, the resolution can be optimized at either high or low energies, but low energy operation will produce images of higher contrast. At an energy of 2 keV or less beam interaction limited resolutions of the order of 3 nm should be possible.     

Measurement of electron probe beam diameter by digital image processing

The present report illustrates a computerized method for precise measurement of the diameter of an electron beam. The value of this measurement extends beyond simply providing an accurate estimate of resolution. Other salient areas which will benefit include quantitative X-ray microanalysis, energy loss spectroscopy, diffraction studies, and electron beam lithography. The biological sciences as well as the material sciences will gain enormously from improved accuracy in measurement (control) of beam diameter. It is anticipated that most or all of the mathematical manipulations outlined in this paper will be incorporated into digital electronic packages which will perform the functions automatically for setting the electron beam diameter to the scientist's choice. The purpose of the present report is to indicate some of the principles involved so that as electron microscopy becomes more computerized and automated, the user will have some understanding of what the electronics are doing rather than simply depressing a button or two and ignoring the power of what resides within the walls of the instrument. The performance of a scanning electron microscope (SEM) and a scanning transmission electron microscope (STEM) is roughly determined by the incident electron probe beam size (diameter) involving a sufficient electron current. In the present paper, the diameter of an ultrafine electron beam is measured indirectly from the information given by the blurring of an edge in a STEM or a SEM image of a crystalline specimen with fine, sharp edges. The obtained data were processed by digital image processing methods which give an accurate value of the beam diameter. For confirming the validity of this method, a suitable simulation based on the convolution theorem was performed. By using this measurement, we could measure the diameter of an ultrafine electron beam down to 2 nm, which could not be measured easily by previous techniques.     

双束聚焦离子束工作原理及微电子领域的应用

聚焦离子束系统以其超强的微加工及微分析能力在微电子领域的地位越来越重要。随着聚焦离子束系统的发展,离子束和电子束结合的双束聚焦离子束系统已经普遍被使用。双束聚焦离子束系统结合了高能离子束和电子束的优点,采用液态镓离子源通过高压引出,并经偏转会聚为离子束实现样品加工,利用高能电子束扫描样品成像,可以做到边加工边观察。本文介绍了双束聚焦离子束系统的组成,主要部件的工作原理及在微电子领域的主要应用,并详述了主要应用的操作方法。     

60kW电子束强流电子枪屏蔽层线性厚度的计算

正常工作下的电子束强流电子枪会产生对人体有害的X射线。如何将这些X射线对操作者的危害降到可以接受的水平成了人们越来越关注的问题。通过计算给出了60kW的电子束强流电子枪常用材料屏蔽层的线性厚度。     

高能束热处理及其在工业中的应用

简要介绍了高能束热处理(主要包括激光热处理、电子束热处理、离子束表面改性)的特征及其基本原理，并通过实例阐述了激光热处理在改善超越离合器星轮表面耐磨性方面的应用，同时介绍了高能束热处理在工业生产中的应用及其发展趋势。     

A very low energy compact electron beam ion trap for spectroscopic research in Shanghai

In this paper, a new compact low energy electron beam ion trap, SH-PermEBIT, is reported. This electron beam ion trap (EBIT) can operate in the electron energy range of 60-5000 eV, with a current density of up to 100 A/cm(2). The low energy limit of this machine sets the record among the reported works so far. The magnetic field in the central drift tube region of this EBIT is around 0.5 T, produced by permanent magnets and soft iron. The design of this EBIT allows adjustment of the electron gun's axial position in the fringe field of the central magnetic field. This turned out to be very important for optimizing the magnetic field in the region of the electron gun and particularly important for low electron beam energy operation, since the magnetic field strength is not tunable with permanent magnets. In this work, transmission of the electron beam as well as the upper limit of the electron beam width under several conditions are measured. Spectral results from test operation of this EBIT at the electron energies of 60, 315, 2800, and 4100 eV are also reported.     

真空电子束焊接工艺研究

研究了8mm厚某铝合金圆筒真空电子束对接焊接工艺，分析了各个焊接规范参数特征区域的特征，探讨了特征参数与接头性能之间的对应关系，并通过一系列工艺试验，得出了该铝合金筒真空电子束焊对接的最佳焊接规范参数。     

Deconvolution of scanning electron microscopy images

This paper describes a method of removing blurs in scanning electron microscopy (SEM) images caused by the existence of a finite beam size. Although the resolution of electron microscopy images has been dramatically improved by the use of high-brightness electron guns and low-aberration electron lenses, it is still limited by lens aberration and electron diffraction. Both are inevitable in practical electron optics. Therefore, a further reduction in resolution by improving SEM hardware seems difficult. In order to overcome this difficulty, computer deconvolution has been proposed for SEM images. In the present work, the SEM image is deconvoluted using the electron beam profile estimated from beam optics calculation. The results show that the resolution of the deconvoluted image is improved to one half of the resolution of the original SEM image.     

Polarization dependence in ELNES: influence of probe convergence, collector aperture and electron beam incidence angle

The differential scattering cross section in electron energy loss near edge spectroscopy (ELNES) generally depends on the orientation of the Q wave vector transferred from the incident electron to an atomic core electron. In the case where the excited atom belongs to a threefold, fourfold or sixfold main rotation axis, the dipole cross section depends on the angle of Q with respect to this axis. In this paper, we restrict to this situation called dichroism. Furthermore, if we take into account the relativistic effects due to the high incident electron velocity, this dipole cross section also depends on the angle of Q with respect to the electron beam axis. It is due to these dependences that the shape of measured electron energy loss spectra varies with the electron beam incidence, the collector aperture, the incident beam convergence and the incident electron energy. The existence of a particular beam incidence angle for which the scattering cross section becomes independent of collection and beam convergence semi-angles is clearly underscored. Conversely, it is shown that EELS spectra do not depend on the beam incidence angle for a set of particular values of collection and convergence semi-angles. Particularly, in the case of a parallel incident beam, there is a collection semi-angle (often called magic angle) for which the cross section becomes independent of the beam orientation. This magic angle depends on the incident beam kinetic energy. If the incident electron velocity V is small compared with the light velocity c, this magic angle is about 3.975theta(E) (theta(E) is the scattering angle). It decreases to 0 when V approaches c. These results are illustrated in the case of the K boron edge in the boron nitride.