利用电子注分析器研究电子枪性能

本文介绍了电子注分析器系统和电子枪电子光学实验的研究,分别对栅控电子枪和阳控电子枪进行了测试,得到了电子注运动轨迹和电流密度分布,并将阳控电子枪的实验结果与实际设计数据和OPERA计算结果进行比较分析,获得了较好的一致性。结果表明,电子枪的电子光学研究可以验证计算模拟结果,有效地为电子枪的结构设计提供实际参考数据。     

W 波段回旋行波管双阳极磁控注入电子枪的设计

回旋行波管是大功率、高频率的微波毫米波器件。根据W波段回旋行波管的要求,设计了双阳级磁控注入电子枪。由电子光学理论,计算得到电子枪的初始参量,然后利用粒子模拟软件MAGIC构造电子枪模型,分析电子枪各个参数对电子注性能的影响,为电子枪设计优化提供了一定的依据。最后优化得到符合设计要求的低速度零散电子枪结构。电子枪阳极电压为70kV,电流10A,电子注速比1.07,电子注横向速度零散0.8%。     

A Fast Computation Technique for RF Performances in Broadband Millimeter Wave Helix TWTs

A computation technique for gain, efficiency and output power in broadband millimeter wave helix TWTs from their dimensions is described. The computed results by modeling are good agreement with experimental measurements. It is shown that the method is fast and useful accuracy. It can be used as engineering design for MMW TWTs.     

星载栅控行波管电子光学系统设计与实验研究

设计了X波段1600 W星载栅控行波管电子光学系统,详细介绍了电子枪和周期永磁聚焦系统的设计过程,分析了磁场峰值对电子注注腰位置的影响,以此为基础优化了过渡区的磁场,获得电子注与磁系统的良好匹配.在此基础上进行了实验验证,经测试静态流通率达到99.4％,满足了整管的设计需求.     

均匀磁聚焦和周期磁聚焦部分屏蔽流过渡区的设计

本文叙述均匀磁聚焦和周期磁聚焦部分屏蔽流过渡区设计的一种方法,指出对于阳极电位与慢波线电位不同的电子光学系统,以及这两个电位虽然相同,但导流系数大,阳极孔效应严重的电子光学系统,它们的过渡区的设计,必须采用非等位空间中的傍轴电子轨迹方程。并对用部分屏蔽流周期磁聚焦的电子光学系统,电子枪区中的电子轨迹与磁力线重合的问题提出一些看法。     

用边界元法计算回旋管单阳极磁控注入枪

提出了以边界元法作为理论基础,分析磁控注入枪问题,推导出用边界元法计算这类问题的基本理论方程。并根据整管要求,设计了单阳极磁控注入枪。利用Fortran语言编制了一个模拟计算磁控注入枪的程序,利用计算机辅助设计,给出了电极形状、电子轨迹和电子注参量。理论分析和实际计算结果表明,利用边界元方法分析磁控注入枪是一种有效的方法,具有很好的优点,这为分析电子光学系统提供了一条有效途径。     

The design and performance of grid-controlled, high-perveance electron guns

The focusing electrode and a probe projecting through the cathode serve as control electrodes for the current from a convergent-beam electron gun. The principal advantage of this type of "grid" is that there is no interception of the high-current-density beam by the probe-grid. This paper presents the design procedure and experimental results for typical probe-gridded guns. The design procedure is used to obtain the desired perveance, beam diameter, and approximate laminar electron flow. The probe geometry that results in a minimum beam distortion is discussed. The range of values of amplification factor obtainable and the influence of probe geometry on this factor are discussed. The magnetic field required for focusing the beam from a probe-gridded gun is compared with that required for perfect laminar flow and for focusing the beam from a nongridded gun of similar design. An electrolytic tank in conjunction with an analog computer was used to plot electron trajectories, with the effect of space charge included, for the probe-gridded gun and a similar nongridded gun. A comparison of the electron optics of the gridded and nongridded gun is made. Electrical breakdown and beam current during the interpulse time are problems considered. Methods used to minimize electrical breakdown and interpulse beam current are presented. Several models of probe-gridded guns were constructed. The measured characteristics of these guns demonstrate that the advantages of grid control can be obtained with only a minor effect on gun perveance and beam focusing.     

场发射阵列阴极在行波管中的应用

场发射阵列阴极应用于行波管的不足主要表现在：FEAs发射不稳定、阴极发射电流密度较低及电子束存在散焦的问题．分析了产生这些问题的主要原因。提出了相应的解决方案,主要包括：提高真空度,选择合适的发射体材料,增加电阻层等,以提高电子发射的稳定性;优化发射体结构参量,改善制作方法等,以增大阴极发射的电流密度;对电子枪结构进行修改,解决电子柬散焦等问题。最后,概述了新型材料——碳纳米管在行波管中的应用现状,目前虽然还不成熟,却表现出了极大的潜力：     

X 波段50MW 速调管电子光学系统的初步设计

：采用PIC 模拟程序对X 波段50MW 速调管的电子光学系统进行了初步的设计。设计的电子枪压缩比>120, 阴极发射电流密度均匀,电子注轨迹层流性良好。模拟设计的电子枪区最大场强达到27.8kV/mm,属于可以承受的范围。     

多注速调管电子光学系统的研究

本文比较系统地阐述了在多注速调管电子光学系统中开展的研究工作。给出了周期反转永磁聚焦系统的设计方法和设计考虑,讨论了控制极调制多注电子枪设计中遇到的特殊问题和解决方法,建立了计算电子光学系统的二维磁场和电子轨迹计算软件,并应用这些软件设计和研制了S波段200kW多注宽带速调管的电子光学系统。该管输出功率180kW,带宽7.6％,效率44.4％,增益大于45dB,电子注通过率89％,高频通过率69-83％。设计计算与实验结果有较好的一致性。     

Output characteristics of high-power low-voltage broadband traveling-wave tubes with helical and ring-rod slow-wave structures

The output characteristics of high-power low-voltage broadband traveling-wave tubes (TWTs) of the C-D band are presented. The decisive role of a continuous high-perveance electron beam provided by a sectoral electron gun is demonstrated. The main features of the TWT computation procedure are described and the results of comparison between calculated and experimental data are presented.     

X波段行波管阳极控制电子枪设计

大功率电子枪设计中的主要问题是如何构成强流电子束和使电子枪中电子束聚焦。利用差值计算的方法初步确定了电子枪几何尺寸参数,进而应用数值模拟的方法计算了电子枪的结构及束流特性,设计了应用于X波段连续波大功率行波管的阳极控制电子枪。该电子枪设计参数为：阳极调制,导流系数为0．44μP,射程大于37mm,注腰半径为1mm。结果表明,该电子枪可完全满足x波段连续波大功率行波管对互作用电子束的要求。     

毫米波带状注电子枪的设计方法

利用理论分析和仿真模拟相结合的方法对带状电子注的产生进行了系统的研究,并提出了一种带状注电子枪的设计方法.首先通过理论分析,提出了一种计算带状注电子枪结构参数的迭代算法,即根据注电压、注电流、电子注注腰处半厚度、阴极半厚度和阴极宽度,计算出带状注电子枪的阴极柱面半径、阴阳极间距、阳极柱面半径和射程等主要参数;在此基础上,通过仿真模拟,为毫米波真空电子器件设计了一种带状注电子枪.     

大功率行波管无截获栅控枪的设计

根据栅控枪的基本设计原理和整管的应用要求，设计了一种高导流系数、高压缩比和高直流工作电压的无截获栅控枪。详细地讨论了无截获栅控电子枪设计方案的选择和参数的确定。设计数据和试验结果十分吻合，并给出了在Ｘ波段大功率耦合腔行波管中的应用结果。     

A new evaluation method of electron optical performance of high beam current probe forming systems

A new numerical simulation method is presented for the electron optical property analysis of probe forming systems with point cathode guns such as cold field emitters and the Schottky emitters. It has long been recognized that the gun aberrations are important parameters to be considered since the intrinsically high brightness of the point cathode gun is reduced due to its spherical aberration. The simulation method can evaluate the 'threshold beam current I(th)' above which the apparent brightness starts to decrease from the intrinsic value. It is found that the threshold depends on the 'electron gun focal length' as well as on the spherical aberration of the gun. Formulas are presented to estimate the brightness reduction as a function of the beam current. The gun brightness reduction must be included when the probe property (the relation between the beam current l(b) and the probe size on the sample, d) of the entire electron optical column is evaluated. Formulas that explicitly consider the gun aberrations into account are presented. It is shown that the probe property curve consists of three segments in the order of increasing beam current: (i) the constant probe size region, (ii) the brightness limited region where the probe size increases as d approximately I(b)(3/8), and (iii) the angular current intensity limited region in which the beam size increases rapidly as d approximately I(b)(3/2). Some strategies are suggested to increase the threshold beam current and to extend the effective beam current range of the point cathode gun into micro ampere regime.     

场致发射阵列阴极电子枪的设计及模拟研究

讨论了微波管用电子枪的一般参数和要求，对于在微波管中应用场发射阵列阴极电子枪的情况作了分析，表明其中存在的主要问题是电子注散焦。通过比较场发射电子注聚焦的几种方法，利用传统电子枪整体聚焦的思想，初步设计了一个场发射阵列阴极电子枪模型，它包括场致发射阵列阴极，一个Whelnelt电极，一个聚焦电极和一个阳极。通过利用Mafia软件对电子注轨迹的模拟计算，对电子枪的聚焦部分进行了改进。     

基于贝塞尔波束的大景深毫米波介质透镜天线设计

提出了基于贝塞尔波束的大景深毫米波介质透镜天线的设计方法.利用轴锥镜生成贝塞尔波束,并根据成像要求分别设计了基于贝塞尔波束的毫米波介质透镜天线和基于高斯波束的毫米波介质透镜天线.在3mm波段进行了仿真测试及分析,仿真结果表明,所设计的基于贝塞尔波束的毫米波介质透镜天线的3dB宽度为3.23mm,景深约为228mm,相较于传统的基于高斯波束的毫米波介质透镜天线,基于贝塞尔波束的毫米波介质透镜天线可实现的景深提升至5倍以上.     

Estimation of RF Parameters for Millimeter Wave Ring-Bar TWTS

In millimeter wave band, interaction impedance and efficiency of the ring-bar circuit are higher than helix. Ring-bar traveling wave tubes (TWTs) do not easy yield backward wave oscillation at high operating voltages. Thus ring-bar TWTs can reach higher power lever. On basic of computation of dispersion and interaction impedance, a fast estimation models of RF parameters for MMW ring-bar TWTs are given in this paper. It is available in designing tube to reduce developing period.     

Recent developments to the MICHELLE 2-D/3-D electron gun and collector modeling code

Recent developments to the MICHELLE electron gun and collector design tool are reported in this paper. The MICHELLE code is a new finite-element (FE) two-dimensional and three-dimensional electrostatic particle-in-cell code that has been designed to address the recent beam optics modeling and simulation requirements for vacuum electron devices, ion sources, and charged-particle transport. Problem classes specifically targeted include depressed collectors, gridded-guns, multibeam guns, sheet-beam guns, and ion thrusters. The focus of the development program is to combine modern FE techniques with improved physics models. The code employs a conformal mesh, including both structured and unstructured mesh architectures for meshing flexibility, along with a new method for accurate, efficient particle tracking. New particle emission models for thermionic beam representation are included that support primary emission, with an advanced secondary emission model. This paper reports on three significant advances to MICHELLE over the past year; hybrid structured/unstructured mesh support, a time-domain electrostatic algorithm, and an ion plasma model with charge exchange.     

发射天线对毫米波全息成像雷达成像质量影响

基于菲涅耳（Fresnel）衍射理论和傅里叶（Fourier）光学理论建立了毫米波全息成像雷达理论模型,其中重点考虑发射天线波束宽度对成像质量的影响。采用矩阵实验室软件平台（Matlab）编制了仿真程序,分别考虑超窄波束、一般波束和超宽波束三种条件下的系统成像效果。仿真结果表明：适当地优化发射天线性能,有助于获得质量更佳的全息成像。