相对论回旋电子注与驻波场互作用的数值计算

本文从相对论电子运动的基本方程推导出横电(TE)模式下回旋电子注速度相位空间的运动方程。它们适合于回旋振荡管互作用空间的数值计算。对于频率为10GHz的变截面腔TE_(011)场型,工作在回旋基波的回旋振荡管的计算,获得了电子效率为57％和轨道效率为72％的结果。对于频率为35GHz均匀截面腔TE_(021)场型,二次回旋波的回旋振荡管得到了电子效率为26％和轨道效率为40％的结果。文中还讨论了开放式谐振腔纵向场分布函数G(T)、腔体内场幅E_0、电子注半径R_b和轴向磁场B_0等因素对回旋管参量的影响,并给出了相应的结果。     

回旋管辐射功率与磁位形的关系

本文将回旋管的工作磁位形概括为统一的表达式,并通过数值求解相对论电子运动方程,着重讨论了工作磁场位形对回旋管电子效率和输出功率的影响。结果指出在回旋管中最佳的磁位场形是立方形分布,其次是最大值不在互作用区末端的抛物形分布。对于提高回旋管的电子效率和输出功率来说,这两种磁位形都要比线性增加的分布和最大值在互作用区末端的抛物形分布为好。     

35GHz三次谐波低电压回旋管理论研究

用动力学理论分析了三次谐波复合腔回旋管中的注-波互作用,选取了工作点;建立了突变复合腔回旋管的自洽非线性理论模型,该模型既考虑了电子和高频场的自洽相互作用又考虑了复合腔过渡部分模式的耦合,基于该理论模型,对一只三次谐波35GHz突变结构复合腔回旋管中电子注与H₆₁-H₆₂高频场互作用进行了数值模拟,当电流20A,磁场为0.442T时,互作用效率为24%,输出功率为210kW.     

提高回旋单腔振荡管电子效率与功率的途径

本文用轨道理论对具有圆柱形谐振腔的回旋单腔振荡管作了非线性理论分析与归一化计算,给出了谐振腔中场分布、电磁储能、Q值等表示式,证明了在互作用区采用抛物线磁场分布可以显著提高回旋管的效率。文中对a(=ν_(⊥0)/ν_(‖0))为1.5和2两种情况进行了计算,研究了电子注电压V_0、绕射品质因数Q_d、电流Io以及电子注位置等因素对回旋管电子效率、输出功率的影响。所得结果具有一定的普适性。     

Ka波段二次谐波回旋速调管放大器的研究

应用自行编制的电子注-波互作用的自洽非线性模拟程序,我们对Ka波段二次谐波回旋速调管放大器的注-波互作用进行了研究.通过对回旋速调管放大器的数值模拟,我们详细描述了二次谐波电子注-波互作用过程中电子群聚的物理图景;并研究了不同变化参数(漂移管长度和静磁场强度)对电子效率的影响.模拟结果表明:设计的二次谐波回旋速调管放大器的电子效率为15.4%,相应的输出功率约为161kW.     

220 GHz回旋速调管放大器互作用理论的研究

应用注波互作用非自洽非线性模拟程序,对220GHz回旋速调管放大器的注波互作用进行了研究;分析了工作电流、工作电压、直流磁场对电子注效率影响。模拟结果表明,设计出的双腔回旋速调管放大器的电子效率为48%,相应的输出功率为20 kW。     

复合腔回旋管的分析与数值计算

本文对复合腔回旋管进行了分析与计算。在双模与多模近似情况下,对复合开放式谐振腔作为一个整体进行了分析,并数值计算了复合腔的谐振频率、Q值与场分布。在此基础上,对复合腔回旋管进行了大信号分析,计算了基波与二次电子回旋谐波情况下电子效率与一些参数的关系。结果表明,选用适当的复合腔结构,可使输出腔工作于高次模式,且可能获得较高的电子效率与很高的输出功率。     

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。     

用于受控热核聚变的兆瓦级同轴腔回旋振荡器的注-波互作用分析

相对于高阶工作模式的单腔回旋管,同轴腔回旋管具有缓解模式竞争,提高单模工作的稳定性,以及增大功率容量的优点,宜用于受控热核聚变中的电子回旋共振加热和电子回旋电流驱动而受关注.详细地研究了工作频率为170 GHz,TE_(34,11),模同轴腔回旋管的结构参数、电子束参数及腔壁损耗对注-波互作用的影响.首先对170 GHz兆瓦级功率模式选择进行分析,给出了工作模式.再次,基于时域自洽非线性理论,编写了时域单模稳态注-波互作用程序,分析了电流、磁场强度和腔壁欧姆损耗对互作用的影响,并对工作参数进行了优化.模拟结果表明:当电子束电流为68 A,工作电压为65 kV,引导磁场强度为6.58 T时,可获得2.18 MW的输出功率,49.23%的效率,外腔壁上的欧姆损耗密度峰值为1.94 kW/cm~2,内导体表面的小于0.15 W/cm~2;互作用效率随速度零散增大而降低,输出频率向下偏移;电子注厚度对互作用也有相似的影响.     

开槽波导3次谐波回旋行波放大管非线性理论与数值模拟

本文讨论了开槽圆柱波导的高频场分布,给出了注波互作用自洽非线性理论,在电子作大回旋运动与考虑速度零散的情况下,采用四阶龙格库塔法,对均匀截面开槽波导３次谐波回旋行波放大管注波互作用进行了数值计算,得出一些重要的互作用规律,为回旋行波放大管的进一步研究打下了基础。     

BEAM-WAVE INTERACTION ANALYSIS IN THE COUPLED DOUBLE CAVITY GYROTRON OSCILLATOR

general equation of electron-wave synchronous interaction is obtained in gyrotron oscillator,in which the effects of guiding center drift and phase of RF field profile is considered.The interactionefficiency is calculated for the second harmonic operation of single TE_(021) mode for a double cavity gyrotronoscillator model,in which the RF field profile and operating parameters of the gyrotron oscillator areregulated in order to get optimum efficiency.It is shown that the efficiency of 53 percent can be obtained for a=1.5.The characteristic of the double cavity configuration is discussed.The bunching processes of thedouble cavities are compared with that of single cavity.The effects of guiding center drift and RF field profilephase on the beam-wave interaction are analysed.     

Self-consistent field theory and calculation for gyromonotron

A self consistent field large signal theory of gyromonotron is studied in this paper. The RF field profile function satisfies a wave equation. The field is determined by cavity geometry and AC electron beam current. The RF field not only satisfies the boundary conditions at the ends of the cavity but also obeys conservation of energy for steady state interaction between electron beam and field. The parameters of a particular gyrotron are calculated numerically using present theory. Effect of some factors on gyrotron characteristic is discussed. Comparison is made between the results of the self consistent field calculations with and without conservation of energy.     

Effect of reflection on gyrotron operation

The effect of wave reflection on the single-mode operation of a gyrotron is investigated with the help of Rieke diagrams. For this purpose, a set of self-consistent equations describing the beam-field interaction is solved, taking into account the effect of the electron beam and the reflection coefficient on the frequency and RF field profile     

Particle Simulation of a 35-GHz Third-Harmonic Low-Voltage Complex Cavity Gyrotron

A self-consistent particle simulation code has been developed for the research of a 35-GHz third-harmonic Low-voltage complex cavity gyrotron. Aided with microcomputer we use FORTRAN to simulate the process of interaction between electron beam and electromagnetic field. About 7000 macro particles are included at the same time. In the program many useful physical graphs are accessible for the further research of this kind of gyrotron such as the field profile, electrons distribution in various spaces, output power, efficiency and et al. Such simulation results may be helpful to the optimization of devices operation parameters     

Analytical treatment of linearized self-consistent theory of a gyromonotron with a non-fixed structure

The linearized self-consistent theory of gyrotron is analytically treated for a self-excited oscillator with non-fixed structure. The self-consistent RF axial field profile consists of four waves, namely the forward and backward travelling waves of the waveguide, and two electron cyclotron waves. According to the magnetic field value (or the detuning parameter), the electron cyclotron wave couples strongly with the forward wave, or weakly with backward wave of the waveguide mode. Also, the starting current and the axial field profile are significantly different for the forward versus the backward interaction.     

Analysis of Aftercavity Interaction in European ITER Gyrotrons and in the Compact Sub-THz Gyrotron FU CW-CI

Possibilities of arising of aftercavity interaction are analyzed in the ITER 170?GHz 2?MW coaxial cavity gyrotron and the 170?GHz 1?MW cylindrical cavity gyrotron, as well as in the compact 394.5?GHz low power gyrotron FU CW-CI. Also, the simulations for the gyrotron efficiency in the presence of aftercavity interaction are performed in the cold cavity approximation. Results of the analysis illustrate the subtle interplay between the geometry of the output taper and the profile of the magnetic field.     

Energy spectra of electrons and depressed potential collector in gyrotrons

Energy distributions of electrons after their interaction with RF field in the gyrotron with the output power 1 MW and frequency 140 GHz are calculated. The energy spectra evolution is studied for the cases when velocity spread, pitch-factor, beam current and cyclotron frequency change. The efficiency of one- and two stage energy recovery systems are investigated.     

The truth about the ripple beam amplifier

The ripple beam amplifier (RBA) is a device which, like the gyrotron, employs the periodicity of an electron beam to obtain RF interaction; unlike the gyrotron, however, the interaction takes place axially between a TM wave and the beam. A simplified explanation of the proposed theoretical operation of an RBA is given in Appendix 1.     

Quasi-optical gyro-peniotron at high cyclotron harmonics

This paper proposes a new kind of device operating at short millimetre wavelength, in which RF radiation generation is based on the interaction of a beam of sub-relativistic gyrating electrons and the RF standing-wave field of a quasi-optical resonator. This device can be called ‘quasi-optical gyro-peniotron’ because it is similar in electron-beam configuration, microwave circuitry and cyclotron resonance properties to the quasi-optical gyrotron and in its operational mechanism to the peniotron. Starting from relativistic equations of motion for the electrons, the calculation formulae are derived. Using computer simulation, a beam-wave interaction efficiency of 43% is obtained for the third cyclotron harmonic at frequency 100 GHz, beam voltage 80 kV and the applied magnetic field 13·3 kG, indicating that this tube will be potentially a high-efficiency high-power source not requiring a superconduction magnet system even within the 150 GHz band.