【作者】 谢鸿全；

【导师】 刘盛纲；

【作者基本信息】 电子科技大学 ， 光学， 2003， 博士

【摘要】 相对论行波管是近二十年来发展起来的一种重要的高功率微波器件，它利用电子注中的慢空间电荷波与结构波发生同步互作用来实现高频信号放大。由于其强功率、宽频带的特点，人们主要将它用于等离子体受控核聚变的回旋谐振加热、驱动相控阵雷达和高能电子加速器的波源，在军事和民用上都有着重要的应用前景。近年来研究发现，当在微波器件中填充了等离子体以后，器件的输出功率和互作用效率得到显著提高，同时等离子体还可改善电子注的传输质量，甚至取消笨重的外加磁场。莫斯科电子工程研究所、美国休斯实验室和马里兰大学在这方面均有报道，开始都主要集中在相对论返波振荡器上，随后对填充等离子体的相对论行波管的研究也日渐增多，我国电子科技大学高能电子学研究所也正在积极地开展该领域的各项研究工作。本文主要围绕等离子体填充大功率微波器件----波纹波导和螺旋线，以及相关问题进行了一些研究和探讨，主要工作如下：1．从等离子体的流体模型和麦克斯韦方程组出发，借助弗洛奎定理，利用场匹配法，推导了在强引导磁场下，等离子体完全填充的波纹波导慢波结构被一有限厚度的环型相对论电子注所激励的色散方程，通过数值计算，本文首次详细地分析了等离子体填充相对论行波管的色散特性，讨论了等离子体的密度、电子注的电压、电流及电子注在慢波结构中的不同位置对行波管的增益、带宽和中心频率的影响。2．本文创新性地建立了等离子体部分填充螺旋线慢波结构的线性理论，数值计算了在不同的等离子体填充密度与填充半径条件下，螺旋线的色散特性、耦合阻抗和行波管的小信号增益。研究发现，在螺旋线中填充了等离子体以后，形成了一种新的混合模式，螺旋线的色散特性与耦合阻抗都发生了很大的变化，行波管的增益得到显著提高。3．通过对等离子体辅助行波放大器基本结构的研究，较系统地分析了该装置各部分器件的原理、特性、功能以及与相关器件的比较。4．利用等离子体的流体模型和场匹配法，创新性地建立了在无引导磁场下，具有离子通道的等离子体辅助行波放大器的线性理论，通过数值计算，分析了波纹波导的各项几何参数如波导平均半径、波纹深度、波纹周期等对等离子体辅助行波放大器高频结构的色散特性和小信号增益的影响，为慢波结构的设计奠定了理论基础。5．通过对等离子体填充光滑圆柱波导和波纹波导的理论分析，在国内首<WP=8>先讨论了在等离子体均匀填充和无限薄等离子体环形填充两种不同的情况下，等离子低频模式的色散特性，并进行了相应的比较。研究发现，在无限薄环形等离子体填充的周期性波纹波导中，等离子体低频模式满足弗洛奎定理，其频率不再受到等离子体频率的限制更多还原

【Abstract】 Relativistic traveling wave tube (RTWT) is an important high power microwave device which has been well developed in the past twenty years. The application mechanism is the interaction of a slow space charge wave, propagating in an electron beam, with an electromagnetic wave supported by a slow wave structure and that the high frequency signal is amplified. The RTWT has a lot of applications, such as the cyclotron resonance heating of fusion plasmas, drivers for new-generation high-energy electron accelerators and the phased array radars. Recently, it has been found experimentally that injected plasma into the RTWT may enhanced the interaction efficiency and the output power. Plasma filling can also improve the transmission quality of electron beam, even make beam transmission without a guiding magnetic field. All-Russian Electrotechnical Institute(VEI), Moscow, Hughes Research Laboratories and University of Maryland have reported their research achievements in this area. At first their research focused on the backward wave oscillator. Then research of traveling wave tube filled with plasma has been reported. At present, much research activities in this area have been carried out in Institute of High Energy Electronics, University of Electronic Science and Technology of China. In this dissertation, the theoretical studies on plasma-filled high-power microwaves devices in both the corrugated waveguide and helix structure have been carried out. The main works are as below:1. A plasma-filled traveling wave tube with sinusoidally corrugated slow wave structure is driven by a finite thick annular intense relativistic electron beam and the entire system is immersed in a strong longitudinal magnetic field. By means of the linear field theory, the dispersion relation for the traveling wave tube is derived. The dispersion characteristic of the RTWT filled with plasma is analyzed firstly by numerical calculation. The trends of the change for gain, bandwidth and center frequency of the RTWT are discussed in detail in different cases: various densities of plasma, transmission places of electron beam, voltages as well as currents. Some useful results have been obtained on the basis of the discussion. 2. A helix type slow wave structure filled partially with plasma is immersed in a strong longitudinal magnetic field. By means of sheath model, the linear theory is built up. Hybrid modes which are formed at frequencies where the phase velocities of<WP=10>electromagnetic wave and electrostatic wave coincide are found. The trend of change for dispersion characteristic, interaction impedance and linear gain is analyzed in different plasma densities by numerical calculation.3. The principle, characteristics as well as structure of the PASOTRON Amplifier have been analyzed. 4. A relativistic electron beam is injected into plasma whose density is lower than the beam’s density. The head of the electron beam pushes out the plasma electrons, leaving an ion channel. The ion focusing force is similar to the magnetic field in binding electrons. The dispersion equation of corrugated waveguide filled with plasma is derived. For TM01 mode, the influence of the gain and bandwidth of relativistic traveling wave tube amplifier affected by geometry parameters of slow-wave structure, such as periods, depth of ripple and average radius of waveguide, are analyzed by numerical calculation. All these are very helpful for designing RTWT.5. The dispersion characteristics of the low frequency plasma modes are analyzed by means of the theory of the smooth walled cylindrical waveguide and the corrugated wall waveguide filled with plasma. Both uniform plasma and infinitely thin annular plasma filling have been discussed respectively. It is found that the dispersion relation without electron beam satisfies exactly the Floquet theorem and the frequency of electromagnetic wave couldn’t be confined by plasma oscillation frequency in a corrugated wall waveguide filled with an infinitely thin annular plasma like it was in a completely plasma fi更多还原