The multipactor electron gun

An electron source based on the multipactoring principle and preliminary experimental results are described. Several uses of such a gun are suggested.     

Non-adiabatic electron gun for gyrotrons

A non-adiabatic electron gun for gyrotron application is presented. Numerical investigations show some important advantages over presently used electrons guns of the magnetron type. In particular, the influence of space charge and the roughness of the emitter surface on the beam properties is significantly reduced. This allows the generation of a hollow electron beam with a low velocity spread and the operation of the gun over the full current range, almost up to the space charge limit.     

Synthesis of the Pierce gun

The design of a Pierce gun is uniquely defined by four parameters: beam voltage, current, waist radius, and cathode current density. The gun convergence angle, cathode spherical radius, anode-cathode spacing, and throw (distance to the waist) are calculated by an iterative procedure which typically converges in four cycles to 0.1°. The anode lens formula of Danielson, Rosenfeld, and Saloom is combined with inverted forms of the Langmuir-Blodgett solution for the spherical diode and the Universal Beam Spread equation for the tunnel region; the iterations match the trajectories at the anode plane. Correction for spherical aberration is made by the method of Frost and Purl as quantified by True. The inverted equations are simple enough to be solved in a few minutes with a programmable calculator. The experimental data of Frost and Purl is used to demonstrate the validity of the procedure for guns of medium perveance.     

没有硝烟的战争

这里不是战场，却有着战场上的紧张激烈；这里没有硝烟，无形的攻击却和隆隆的炮火一样猛烈。在保护民用航空无线电专用频率整顿活动中，我们忠诚的“空中电波卫士”怀着对蓝天的款款深情和对洁净电磁环境的责任感，在这无形的战场上与干扰电波信号进行着一场场没有硝烟的战争．为民航的安全运营保驾护航，谱写着一曲曲感人的篇章……     

红外搜索与跟踪系统中光学指向器的设计

给出了一种红外搜索与跟踪（IRST）系统中红外指向器的设计方案,在分析了IRST系统及指向器整体特点的基础上,着重讨论了红外指向器各组成部分的工作原理及设计方案。红外搜索与跟踪系统要求目标搜索范围大、周期短、系统反应时间短,同时还要求体积小、质量轻,并尽可能降低成本。为了达到以上目的,采用了六棱台转鼓结合双面翻转反射镜扫描光路的方案,较好地达到IRST系统的各项指标要求。对伺服控制系统的设计是根据不同组件对速度、位置精度的要求选用合适的驱动电机、编码器与控制方法,力求满足精度要求的同时做到体积小、成本低。实验证明,此红外指向器技术先进,方案合理,其性能达到了IRST系统的各项指标要求,目标搜索实验效果良好。采用巧妙的设计方案有效解决了IRST系统大视场快速扫描与轻小型化、低成本化的问题。     

A design of triode electron gun

A theoretical study has been made of the focusing of high-current electron beams by means of the aperture effect. The aperture effect is obtained by a triode electron optical system. An equation for describing the beam profile in the system has been described. Both the condition for obtaining the minimum radius of the beam and the condition for optimum focus have also been worked out. Two numerical examples are treated to illustrate the triode focusing of electron beams with two different total current magnitudes of 50 and 250 µa. It is found that by using this triode system the final energy of the electrons and the total current of the electron beam may be adjusted separately.     

Preliminary study of gun emittance correction

The standard emittance calculation removes linear correlations between transverse displacement r and the divergence r'. Higher-order correlations remain, and they are responsible for a substantial area in phase space which corresponds to the calculated emittance. Time dependent correlations are identified, and a procedure is proposed to remove them. The Brookhaven National Laboratory radio frequency (RF) gun has been studied; however, in order to demonstrate the desired effects more clearly, the accelerating field and bunch length have been assumed to be more optimistic than the present operating values. This approach reduces the realizable emittance by a factor of 5 with respect to the value before the correction     

电子枪理论研究的新进展

本文简要回顾了电子枪发展的历史,评述了电子枪理论研究方面的新进展,重点介绍了日本学者Fujita和Shimoyama的新近研究成果。最新的研究表明,对冷场发射和扩展的肖特基发射电子枪,存在阈值电流。当束流,Ib增大,超过阈值电流时,枪的表观亮度逐渐下降。当对整个电子光学柱体进行评价时,必须把亮度和束流的函数关系考虑在内。这时会出现关于电子枪的若干新概念。整个电子光学柱体的电子探针性质曲线由三个区域组成,即：（1）恒定束斑（d）区;（2）d∝I3/8b,妒区;（3）d∝I3/2b区。以往的理论只指出了3／8次方区的存在。3／2次方区的存在是一个新的发现。它解释了历史上曾注意到的一个事实,即当应用的束流进入μA量级时,扩展的肖特基发射和冷场发射枪的性能反而不如传统的钨丝热发射枪。     

一种同轴线圈——轨道复合型电磁炮

电磁炮是一种高速动能穿甲武器,文章设计了一种新型同轴线圈——轨道复合型电磁炮,并分析了该电磁炮的机械结构、储能原理和加速过程,最后试制了实验样机,采用钢钉为发射体成功进行了弹体发射,可实现线圈炮和轨道炮的优势结合,促进复合型电磁炮从理论研究走向实践应用。     

Ring-and-line-focus electron beams from a glow-discharge gun

Electron guns have been developed in which a high-voltage cold-cathode discharge, at low pressure, generates an electron beam. By shaping the cathode, the beam may be focused in a particular contour. For example guns operating at 3kW at 15kV have been designed to focus in an annular ring or in a line.     

The range of magnetron injection gun parameters

Here, for the first time, the computer designs of axially symmetric magnetron injection guns are given in detail, and the practical problems of computing the electrodes are discussed. These designs have been experimentally used, showing that the design procedure is sufficiently accurate for predicting the characteristics. The important design parameters such as perveance, area convergence and magnetic field required are given for the interesting range of the normalized "computer" parameters. A method is suggested for computation of the resulting hollow beam from a truncated cone cathode, and the design of a transition region is discussed.     

新型小尺寸带引向器波纹开眼对拓型Vivaldi天线

基于传统对拓型Vivaldi天线, 提出一种新型小尺寸对拓型Vivaldi天线.采用波纹、开眼和引向器等结构来展宽天线的工作带宽, 并分别对这三种结构对带宽的影响进行了分析.利用HFSS仿真优化得到的结构参数, 分别在两种介质材料上, 加工并测试了带引向器波纹开眼对拓型Vivaldi天线, 实测与仿真结果吻合.仿真与测试结果表明:两种介质上的天线工作频带均包含3~20 GHz, 尺寸仅为42.56 mm×40.16 mm×0.813 mm, 带内回波损耗S₁₁低于-10 dB, 带内增益均大于3 dBi, 最大增益达7.3 dBi, 交叉极化均小于-15 dB, 50%以上的频带交叉极化小于-20 dB, 最小可达-25 dB, 天线具有稳定的方向图, 良好的波形保真度, 是一种宽波束天线.     

中国无线电协会第一次理事长办公会议召开 谢飞波局长、朱三保常务副理事长为协会揭牌

中国无线电协会（简称＂协会＂）第一次理事长办公会议7月23日在京召开。会议听取了协会近期工作情况汇报,审议了5项内部管理制度,讨论了协会办事机构、分支机构的设立和新会员的吸纳等问题,并举行了协会揭牌仪式。此次会议的召开,标志着中国无线电协会已进入到正式运行的阶段。工业和信息化部无线电管理局局长谢飞波、     

Multipactoring electron gun for high duty linacs

A high duty factor electron gun suitable for linac applications is described. This gun operates on the secondary emission principle to generate a pulsed, monochromatic electron output beam in excess of 20 mA average current. It has been operated at 14 percent duty factor and shows a high degree of stability and ease of control.     

Generalization and synthesis of the Kino gun

A more general transformation is given for the cross-field gun problem, allowing for an arbitrary emission velocity; Kino's Solutions I and II then appear as particular cases. Close investigation of the region between the cathode and the front and rear focus electrodes (which must be separated to avoid thermal and migration problems) shows that all designs with nonzero emission velocity are theoretically flawed: imaginary ledges would be needed to connect the cathode surface to its supports. In addition, Kino's Solution II is shown to be unattainable because the slightest departure of the emission velocity from the prescribed value introduces singularities between the cathode and the accelerator electrode. Despite the theoretical flaws, useful designs can be generated in the neighborhood of Solution I, but matching realistic emission velocities on the order of 0.1 V. A synthesis procedure for this Solution III is given, which determines the electrodes in terms of the required exit-beam dimensions and current, the allowed cathode current density, and the electrode voltages.     

GPC算法在火炮随动系统中的仿真研究

计算机技术和数字化技术的发展,使得构成火炮随动系统的各元件,从质量和性能上都有了很大的提高;随着硬件的制造工艺有了很大改进,使得软件可做到更加精确,在使控制率的设计、调整和维护更加便捷可靠的同时,对于控制中存在的非线性和不确定性因素的影响,用软件设计算法比硬件更简洁且便于维护。本文使用GPC算法对CARIMA模型（受控自回归积分滑动平均过程模型）进行模拟仿真,使用多步预测、滚动优化的方法检验算法在受到非平稳随机扰动的不稳定系统中的控制性能。仿真结果证实了该控制策略的优越性。