电极零件的卷边与极间高压击穿

电子束管是电真空器件的一种,它通常由抽成真空的玻壳及封入其中的电子枪构成。作为管芯的电子枪是电子束管的心脏,无论是那种类型的电子束管都缺少不了电子枪。电子枪是由阴极发射透镜、预聚焦透镜、主聚焦透镜、偏转棱镜等一系列电子透镜依次组合装配而成的电子光学系统。轴对称静电式电子透镜,均是由馈以不同直流电压的圆筒型电极零件按不同间隙装架而成。除掉阴极、调制极外,各个     

束流电子光学理论的发展

传统的射线电子光学理论基于计算单电子在电子光学系统中的运动轨迹,而束流电子光学则是研究在位置—动量的相空间中电子束的传输性质。近年来束流电子光学在核物理和加速器物理、质谱学和能谱学等领域中有了广泛发展。但是目前国内外束流电子光学理论多数是发展了线性的一级理论。作者近年来发展了考虑三级、五级象差的束流电子光理论,研究的对象包括:旋转对称电子光学系统,直线轴和弯曲轴的电磁聚焦—偏转复合系统,磁圆形透镜和六极透镜的复合系统,圆形透镜与四极、八极透镜的复合系统,显然射线电子光学和束流电子光学两种理论在原则上是一致的,但是我们上述的束流电子光学理论较     

全息校正GRIN透镜像差

梯度折射率(GRIN)透镜的像差会导致像面弥散斑增大从而降低透镜的聚焦性能。基于激光全息成像理论,利用全息技术来校正GRIN透镜的像差,从而改善其聚焦性能。通过对GRIN透镜全息校正系统的仿真,计算了全息记录时通过GRIN透镜的物光波在全息图上的相位分布,得到其波像差为0.34λ;分析了全息再现时全息干版的轴向位移对像面弥散斑成像质量的影响,提出一种通过引入轴上点像差平衡轴外点像差的方法并进一步提高了聚焦性能。结果表明:应用该方法在1.5°视场内,弥散斑均方根半径值由14.1μm减小到7.2μm。在3°全视场内,弥散斑均方根半径值均在衍射极限范围内,能够满足GRIN透镜在重叠复眼成像系统中的聚焦要求。     

静电圆锥透镜曲轴电子束聚焦理论的研究

在曲轴宽电子束聚焦理论的基础上，本文研究了静电圆锥透镜聚焦性质，提出了静电场中考虑主轨迹为平面曲线情况下电子束的焦点、焦距等电子光学基本参量的定义。作为例子，给出了两种类型的静电圆锥透镜的电子光学在不同电参量下的关系曲线。     

盒式扫描扩展透镜分析

一、前言静电偏转阴极射线管采取过很多种扫描扩展方案,球形网(dome-shaped mesh)就是其中之一。采用球形网虽然能获得几何畸变小和扫描线性好的显示,但是,由于网与电子束的相互作用,会使束流减小,束点散焦和产生次级发射。采用静电四极透镜(electros-tatic quadrupole)固然可以避免球形网的限制,然而,这种平面对称透镜不能获得像球形网那样出色的几何和线性特性,而且要获得圆形的光点,还需要附加的四极透镜,这就增加了问题的复杂性。     

磁聚焦变像管像场弯曲的改善研究

研制大面积阴极磁聚焦分幅变像管。在2:1电子光学倍率下,研究单磁透镜和双磁透镜成像的像场弯曲。基于光学透镜成像原理,假设成像面形状不随激励微调而改变,推导了离轴点最佳成像位置与激励变化的近似关系式,并由此提出一种测量并减小像管像场弯曲的方法;借助Matlab编程模拟了像管各离轴点的最佳成像位置,拟合得到成像曲面方程,并利用所提出的像场弯曲测量方法进行了测试验证。结果表明,在一定视场范围内,计算机模拟与实验测试结果比较接近。单、双磁透镜下的最佳成像面均为旋转抛物面,但双磁透镜成像像场弯曲比单磁透镜有明显的改善。     

电子束聚焦和偏转系统中动态修正的计算

在电子束聚焦和偏转系统中动态修正方法(即用场曲校正透镜和消象散器来消除偏转场曲和象散)可以相当显著地减小系统的总象差和提高系统的电子光学性能。本文讨论了动态修正的计算问题:包括场曲校正透镜和消象散器的工作原理;校正透镜和消象散器电磁场分布的计算;完全消除场曲和象散在校正透镜和消象散器上所加信号强度的计算;以及校正透镜和消象散器对畸变的影响。通过文章给出动态修正计算的实例可见动态修正对提高系统的电子光学性能起着很大的作用。     

毫米波焦面阵成像视场扩大分析

本文研究平面波倾斜入射在小F数毫米波焦面阵成像系统上衍射斑像差减小即视场扩大问题.采用射线追迹方法计算不同透镜剖面成像系统焦面上的点列图,对商用介质材料透镜通过优化剖面形状来减小像差从而获得视场扩大的效果.采用结合射线追迹和衍射积分的矢量孔径场法计算了透镜焦面上的衍射场分布,与实验结果做了比较,两者吻合.     

一字型枪边束优化设计的新方法

在一字型彩色ＣＲＴ中,用Ｇ２、Ｇ３进行会聚电子束,在这样的电子枪系统中,边束电子束在预聚焦透镜处（在Ｇ２和Ｇ３电极之间）向轴向弯曲,此后,电子束倾斜进入主透镜系统。边束电子空过主透镜的正确位置,从而减小光点彗差,同时电子束随聚焦电压情况漂移。为了精确估计电子束在三维结构主透镜中的正确位置,提出了一种新的计算方法。     

毫米波焦面阵成像视场扩大分析

本文研究平面波倾斜入射在小F数毫米波焦面阵成像系统上衍射斑像差减小即视场扩大问题．采用射线追迹方法计算不同透镜剖面成像系统焦面上的点列图，对商用介质材料透镜通过优化剖面形状来减小像差从而获得视场扩大的效果．采用结合射线追迹和衍射积分的矢量孔径场法计算了透镜焦面上的衍射场分布，与实验结果做了比较，两者吻合．     

DDF-Ⅱ型动态聚焦电子枪的研制

在DDF-Ⅰ电子枪基础上，改变电子枪结构，将G5分成三部分，将G52／G53之间的四极场，增加G51／G52之间的四极场，通过改变四极场位置和电子束在主透镜的入射角来减小四角电子束的水平尺寸。调整G51／G52之间水平翼片的长度，让四极场场强达到合适的值，使屏面中心和四角的光点尺寸同时达到最佳。通过反复模拟计算和实验测试，最终确定了能获得满屏良好聚焦性能的DDF-Ⅱ电子枪结构。     

彩色显像管中主聚焦透镜的研究

在COTY系统中,采用XL透镜来改善会聚性能,减小会聚/聚焦之间的矛盾。XL透镜可以在不损失聚焦性能的前提下缩小束间距提高会聚特性。但是在XL透镜中边束像差比中束大得多,为了进一步降低像差,本文提出在XL电子枪中采用OLF透镜来扩大透镜的孔径,改善分辨率。本文给出了三维计算机程序,对主聚焦透镜进行三维计算,得到了球差系数和其它光学参量。这些数据证实了在新的方案中球差确实被降低,而且会聚特性也得以改善。     

A combined objective lens for electrons and ions

Nanofabrication is possible using focused ion beam technology, but the observation of these structures with the same ion beam is not possible because of its erosion effect. Therefore a general purpose instrument for nanotechnology based on particle optics has to combine an ion and an electron beam. The objective lens, the final lens above the specimen, has to focus both beams on the specimen. An objective lens that combines magnetic and electrostatic fields has been designed for this purpose. Its aberration coefficients allow a 1 nm ion beam and a 0.3 nm electron beam.     

The autoresonant peniotron with a quadrupole interaction circuit

In the autoresonant peniotron interaction, all of the electrons will be able to give almost all of their kinetic energy to an electromagnetic wave, resulting in a conversion efficiency of nearly 100%, if the condition of V_p=C is satisfied in an interaction circuit and the initial velocity ratio of electrons is correctly given as a function of the electron kinetic energy. A quadrupole circuit is proposed in which the above circuit condition is usually satisfied and the RF electric field distribution in a cross section is suitable for the peniotron interaction at the fundamental cyclotron frequency. The design procedure for the test tube with the circuit and some simulation results concerned with the tube's operation are described     

扫描电子束曝光机复合物镜的研究与设计

在综合研究已有的各种复合物镜(如移动物镜、变轴物镜和摆动物镜等)的基础上,本文对复合物镜的一般理论进行了探讨,推导了普遍化计算公式,并提出新的复合物镜(弯曲物镜)系统。采用解析函数近似表示系统场分布,对弯曲物镜系统象差进行了理论分析,并设计出一个实际系统。数值计算结果给出该系统在55mm2扫描场内,束孔径角5mrad和能散2.5eV下,最大彗差0.005m,横向色差0.001m。     

Monte Carlo simulation of the energy dissipation profiles of 30, 50 and 100 keV incident beams in a layered structure in electron beam lithography

This paper presents a Monte Carlo simulation of the energy dissipation profiles of 30, 50 and 100 keV incident beams in thin film (0.4μm) of electron resist, polymethyl methacrylate (PMMA), on thick silicon substrate in electron beam lithography. The radial scattering and the energy loss of incident electrons (including backscattered electrons from the substrate) are simulated under the illumination of ideal point source and Gaussian round beam spot source, and the histories of 30000–50000 electrons are computed.     

透射电子显微镜单色器的发展及应用

自1932年透射电子显微镜发明以来,透射电子显微学在基础理论、仪器研制及其在材料科学、生命科学等领域的应用得到了迅速发展,200kV场发射枪透射电子显微镜的点分辨率已达0.19～0.25nm,能量分辨率为0.7～1.0eV。进一步提高透射电子显微镜性能的关键在于降低物镜球差和电子束能量扩散等。球差校正器的发明使透射电镜的点分辨率已突破0.1nm,电子源色差已成为进一步提高电子显微镜信息分辨极限和电子能量损失谱能量分辨率的瓶颈。在场发射枪透射电子显微镜上增加单色器（能量过滤器）可有效降低电子束的能量色散,减小色差对电子显微镜性能的影响。本文介绍了Wien型、Ω型及Mandoline型等几种常见的能量过滤器的工作原理、结构、性能及其应用。     

Efficient electron beam condensing for low-energy microcolumn lithography

Low-energy electron beam lithography has been performed with a microcolumn by adopting a new technique that condenses the electron beam efficiently. To increase the probe current while keeping the kinetic energy of electrons sufficiently low, the negative or positive bias has been applied to the accelerator electrode, which reduces the divergence of the electron beam and hence makes more electrons pass through the microcolumn. With this technique, the probe current more than 1 nA has been achieved, which is large enough for the practical application of microcolumn lithography even when the kinetic energy of electrons is as low as 160 eV. The results of microcolumn lithography by using the condensed electron beam with a low-energy of 160 and 327 eV are also presented.     

Beam alignment and related problems of spherical aberration corrected high-resolution TEM images

For spherical aberration corrected transmission electron microscopes recently developed, the Scherzer resolution in proportion to C(s) 1/4 lambda 3/4 is still inevitably limited by the influence of some other electron optical factors, such as chromatic aberration coefficient of objective lens (C(c)), beam divergence and alignment, incident electron energy spread (deltaE), and the instability of accelerating voltage (deltaV) and of lens current (deltaI). Depending on the image resolution guaranteed by C(s) correction, the defocus spread caused by C(c), deltaV, deltaI and deltaE would need to be reduced. The effect of beam alignment as a phase shift in contrast transfer function is also studied for the C(s) corrected microscopes with different values of C(s), defocus and spatial frequency. There is a relationship between the phase shift and defocus that allows us to find a series of 'alignment-free' focal conditions. A triangular relation among C(s), defocus and lattice spacing is established for proper image contrast and 'alignment-free' imaging with the C(s) corrected microscope.     

Simulation of the Field Emission Arrays with Parallel Wedge Emitter, Gates and Co-Planar Lens

Using the particle-in-cell (PIC) simulation code MAGIC, the wedge emitter, parallel gate and anode with and without co-planar lens have been simulated. The electron beam streamlines and the X-V_x phase space have been evaluated, which show that the co-planar lens focuses the electron. Simulation results are presented for a single FEA's cell with the anode biased at 500V and spaced 100μm from the cathode, which indicated that the electron beam width at anode is about 60.2μm for without lens FEAs, after add the lens with ?70V, the electron beam width will be decrease to 8.1μm, meanwhile the maximum transverse velocity will decrease from ±1×10⁶m/s to ±1.46×10⁵m/s.