3mm二次谐波回旋振荡管设计与数值模拟

二次谐波回旋振荡管的互作用磁场比基波回旋振荡管的磁场降低了一半,从而降低了设计难度,具有广阔的应用前景。通过对单腔结构的W波段二次谐波回旋振荡管高频结构、起振电流、模式竞争以及注波互作用研究,确定了W波段TE02模二次谐波回旋振荡管的基本工作参数,通过粒子模拟(PIC)软件进行计算,在电子注电压为60kV,注电流为6A及速度比为1.5时,获得了67.5kW的输出功率和超过18%的效率,且工作稳定。     

矩形π-TM310 双间隙腔加载同轴滤波器型宽带输出电路研究

本文提出了矩形π-TM310 双间隙腔加载同轴滤波器型宽带输出电路,并对其可行性进行了论证,对高次模双间隙腔中非工作模式的干扰程度和同轴线输出电路的功率容限等重要问题做了定量分析。我们通过调整矩形双间隙腔的长宽比例并采用凹入结构,明显扩大了π-TM310模与相邻非工作模的频率间隔,有效抑制了非工作模式的干扰;又采用了非常规的电子注孔布局,使各个电子注孔的特性阻抗更均匀,而且在加载同轴滤波器之后仍然很均匀。研究结果表明,经过优化设计的矩形π-TM310 双间隙腔加载同轴滤波器型输出电路具有很宽的输出频带,在X波段相对带宽达到14%左右。但由于π模双间隙腔与同轴线的耦合口较小,而且该处还有短路销钉,导致其输出功率容限较低,约为几百kW。因此,该类输出电路比较适合于X波段或更高频段的中功率宽带多注速调管。     

矩形π-TM310模双间隙腔加载同轴滤波器型宽带输出电路的实验研究

本文详细介绍了矩形π-TM310模双间隙腔同轴滤波器型输出电路的实验研究过程,以及针对一些关键技术难点所采取的改进措施.测试数据显示,矩形π-TM310模双间隙腔与输出同轴线的耦合强度适中,其外观品质因数30左右,在加载同轴线之后各个电子注孔特性阻抗的均匀度仍然较好;矩形π-TM310模双间隙腔同轴滤波器型输出电路的输...     

复合周期磁场共轴回旋电子注回旋单腔管的研究

本文在吴坚强(1985)、刘盛纲(1985)工作的基础上,利用线性动力学理论对复合周期磁场共轴回旋电子注回旋单腔管进行了详细的理论分析。推得了注波互作用功率、频偏和起振电流等公式。     

W波段低电压三次谐波回旋振荡管

回旋振荡管采用三次谐波工作方式的互作用磁场只有基波状态磁场的三分之一,可有效降低设计难度,具有广阔的应用前景。通过对三段式单腔结构的耦合系数、起振电流、高频场分布、模式竞争以及注波互作用研究,确定了工作模式为TE03的W波段低电压三次谐波回旋振荡管的基本工作参数;通过粒子模拟软件(PIC)模拟分析,在电子注电压、注电流及速度比分别为35 kV、4 A和1.6时,在93.7 GHz频点处获得15.57 kW的输出功率,效率约11.1%,且该管可在此工作模式下稳定工作。     

π-TM_(610)模同轴双间隙腔耦合同轴线输出电路

该文提出一种适合于X波段多注速调管的π-TM₆₁₀模双间隙同轴腔的同轴线输出电路,并详细分析了其带宽和输出功率容限等重要性能,结果表明：π-TM₆₁₀模双间隙同轴腔耦合同轴线之后,输出腔中各个电子注孔的特性阻抗仍然很均匀;但由于输出腔外观品质因数太大而且无法使其降低,导致输出频带较窄;输出功率容限则为1MW左右。因此它比较适合作为高射频段的高功率窄带多注速调管的输出电路。     

140 GHz, TE22,6模式回旋振荡管高频谐振腔

通过数值计算方法,编程模拟了140 GHz, TE22,6模式回旋振荡管开放式缓变截面谐振腔的传播特性,计算出谐振腔的谐振频率和品质因数;利用CST软件对该高频谐振腔进行仿真计算,得到腔体内横截面的电场分布云图。通过实验和仿真软件得到的数据进行比较,两者有较好的一致性。测试结果表明,当磁场为5.48 T,电子注电流为28 A,电子注电压为68.6 kV时,TE22,6模式的平均输出功率为0.25 kW,峰值功率为0.56 MW。当磁场为5.68 T,电子注电流为27.6 A,电子注电压为69.12 kV时,回旋振荡管可同样工作于TE22,6,2模式,平均输出功率为0.21 kW,峰值功率为0.47 MW。     

3-节滤波器型π-模双间隙腔加载同轴-矩形波导输出电路研究

该文提出了一种适合于低频段中等功率的宽带速调管的新型3-节滤波器型输出电路-π-模双间隙腔加载同轴-矩形波导输出电路,并对输出电路的性能以及各部分结构对输出腔间隙阻抗的影响规律进行详细研究.研究结果表明,同轴-矩形波导混合型输出电路不仅克服了低频段宽带速调管中输出波导尺寸太大而影响聚焦系统的困难,有利于提高电子注通过率和整管效率,同时还具有很好的输出带宽潜力和良好的高功率承受能力.     

多注双间隙耦合腔电子电导计算与模拟

该文基于空间电荷波理论模型,推导出多注双间隙耦合腔电子电导的单模理论和多模理论计算公式。比较结果显示对于双间隙耦合腔,单模理论计算结果足够准确。由粒子模拟结果与计算结果的一致证明了计算结果的正确性。最后使用粒子模拟研究了电压调制系数和聚焦磁场对电子电导的影响。结果显示当电压调制系数小于0.1并且聚焦磁场大于1.5倍布里渊磁场时,小信号理论计算的电子电导是准确的。     

高次模多注速调管的矩形双间隙输出腔的研究

研究一种工作在TM1202高次模的速调管矩形双间隙输出腔模型。运用Mafia三维电磁场计算软件对模型进行计算机模拟,得出TM1202工作模式的频率、特性阻抗和场分布。加工了TM1202高次模多注速调管双间隙输出腔模型并进行冷测试验,测试结果与计算相符,并对计算和测试结果进行了分析。对该模型的研究为进一步研制工作在TM1202高次模多注速调管的高频输出系统提供了理论依据。     

Design formulae of unsymmetrical double-gap output cavities of klystrons

A new perspective is proposed that unsymmetrical double-gap output cavities of klystrons will have greater energy conversion efficiency of beam to microwave than the conventional symmetrical double-gap output cavities. The equivalent circuit method is used to get the relationships of the two gap electric fields in π-mode and 2π-mode unsymmetrical double-gap cavities in the case that the two gaps of the unsymmetrical double-gap cavities are approximately regarded as parallel grid gaps. The energy conversion efficiency in the process of an ideal bunching beam passing through the π-mode or 2π-mode unsymmetrical double-gap cavity is calculated by simulating the ideal cluster beam with a succession of periodically repeated electrons; then, the formulae of the optimal gap width, the optimal length of the drift tube between two gaps and the optimal gap voltage amplitude corresponding to the maximal conversion efficiency are obtained, which can be used to design π-mode and 2π-mode unsymmetrical double-gap output cavities of klystrons.     

An Axial Monotron with Rippled Wall Resonator

With application to centimeter-wave monotron oscillators, the present work proposes a rippled wall cylindrical cavity that provides efficient coupling to a coaxial output circuit. Driven by a centered, solid 50 A, 34 keV electron beam, the corrugated cavity thus designed operates at 10.5 GHz in the 2π-mode with two radial variations. The monotron operation is examined through 2.5D particle-in-cell simulation giving 260 kW average power output. This corresponds to 15.3 percent overall efficiency at the theoretical limit of 20.0% percent electronic effciency as predicted by one-dimensional analysis.     

Large-signal behavior of distributed klystrons

A theoretical large- and small-signal analysis of the behavior of standing-wave-type distributed circuit klystrons, based on a confined flow model, is described. A two-cavity klystron with a π-mode double-gap distributed output circuit and a conventional single-gap input cavity was selected as a specific example for study. The field distribution for the experimental cavities was measured and a conversion efficiency of 52 percent was predicted. The effects of the output cavity position relative to the input cavity, the output cavity gap angle, and the space charge were analyzed theoretically. The theoretical results were compared with measurements made on a precision demountable klystron with identical beam and circuit parameters, but with a Brillouin-focused beam rather than a confined-flow beam. A load efficiency of 35 percent, a conversion efficiency of 42 percent, and small-signal gains up to 15 dB were measured. The corresponding figures for the conventional single-gap output circuit were 24 percent, 28.6 percent, and 9 dB. The measured effects of changes in the tube parameters were in general agreement with the theoretical predicted results. The study indicates that the π-mode double-gap cavity is a very practical output structure yielding high efficiency with a very short interaction length. It should prove useful in medium- and high-power klystrons.     

STUDY OF CROSSED FIELD GYROTRON OPERATING ON WHISPERING-GALLERY MODE

A linear and nonlinear analysis of crossed-field gyrotron operating on whispering-gallery mode TE_(m11) is presented. The detailed discussions are given for the starting oscillationcondition, the effect of the internal conductor in coaxial cavity on the cut-off frequency of modeand the spacing between adjacent modes as well as the effect of the applied voltage on thecyclotron frequency of electron, the starting oscillation beam power and the electron efficiency.It is shown that the efficiency of 41% can be attained for m=2. A comparison of these resultswith those in cylindrical cavity is made. The analyses are helpful for the engineering design.     

具有正交直流场的边廊模(TEm11)回旋脉塞的研究

本文给出了具有正交直流场的边廊模回旋脉塞的线性和非线性分析。对模型的小信号起振,同轴腔内导体对模式的截止频率和分割度的影响以及外加电压对电子回旋频率,起振束功率和互作用效率的影响作了较详细的研究。计算表明,对m=2,互作用效率可达41%。我们还将其结果与相同条件下圆柱腔情况作了比较。这些分析有益于工程设计。     

大功率速调管中寄生振荡问题的实验研究

本文详细地描述了在S波段20MW大功率速调管和S波段1.5MW宽频带速调管中观察到的两种不同类型的振荡现象。实验和理论分析表明,一种类型的振荡足电子枪区的二极管振荡,另一种类型的振荡是由速调管谐振腔的高次模TM011引起的模型单腔振荡。为研制工作稳定可靠的高峰值和高平均功率速调管提供了有价值的理论和实验依据。     

A coupled-monotron analysis of band-edge oscillations in high-power traveling-wave tubes

A theoretical analysis of the interaction of an electron beam with a coupled-cavity structure near a band-edge frequency is presented. The analysis utilizes the resonant modes of the individual cavities in a way such that the details of the electronic interaction within each distinct cavity are identical to those of the monotron theory, but the coupling between adjacent cavities is taken into account via the circuit equations. There arenequations obtained forncavities, and an algebraic rather than a characteristic wave type of approach is chosen for their solution. The theory is applied to finding the starting conditions for band-edge oscillations in an untapered structure. The results are verified experimentally. The theory also indicates that it is probably valid to use the simple monotron theory to find the minimum start-oscillation length or current.     

Gyrokinetic Analysis of Influence of Electron Beam Eccentricity on Operation of Higher-Order Mode in a Coaxial Cavity Gyrotron

A gyrokinetic analysis is presented to the influence of the electron beam eccentricity on the power and starting current of a coaxial cavity gyrotron, which operates in a higher-order mode TE_31, 17, 1 with a frequency of 165 GHz. It is found that the starting current becomes larger because of the existence of the electron-beam eccentricity. Especially, the power will be decreased substantially by the electron beam eccentricity, for example, down to 93% of the power without any eccentricity even if the eccentricity is 1% of the outer conductor radius. The acceptable range of the electron beam voltage and operating magnetic field for the establishment of the electromagnetic oscillation is narrowed by the electron-beam eccentricity.     

双间隙双耦合口输出回路间隙阻抗的模拟计算

本文根据微波网络理论，建立了双间隙双耦合口输出回路间隙阻抗频率特性的冷测模拟计算方法。运用该方法，计算分析了某S波段双间隙双耦合口输出腔的间隙阻抗频率特性。结果显示，本方法与采用场分析法得到的结果符合良好。