In this paper, the simulation and design of a diode type magnetron injection gun (MIG) for a W-band CW gyrotron oscillator is presented. The simulation of the MIG, operating at the voltage of 55kV and the current of 4A, is finished with the help of a trajectory program EGUN. The simulation results indicate that the velocity ratio with velocity spread of less than 2.5% is 1.43.

分析了单注折叠波导行波管增益和带宽的限制因素,提出了采用双注结构提高单位长度增益和拓宽带宽的方法。模拟结果表明,在工作电压和单注电流相同的情况下,采用同速双注（两电子注速度相同）可将高频互作用系统饱和输出功率提升至单注时的2.8倍,互作用效率提高了1.4倍,增益饱和长度缩短了5个几何周期;采用非同速双注可在更宽的频率范围内满足同步条件,展宽了带宽。设计了一工作频率为25~29.5 GHz的宽带折叠波导行波管,3 dB增益带宽可达到16.5%,约占冷带宽（12 GHz,22~34 GHz）的38%,输出功率在27 GHz时达到最大为256 W。另外,文中对由电路内部反射引起的增益不稳定性进行了分析,并给出了解决方法。

The design of a W-band four-cavity gyroklystron amplifier is presented. The device operates in the fundamental harmonic TE01 circular electric mode. The 70 kV, 6 A beam is produced by a double anode magnetron injection gun (MIG) with an average perpendicular-to-parallel velocity ratio of 1. 5 and a parallel velocity spread of less than 4%. (PIC) simulations have been performed to predict general RF performance for various parameters. The simulated results show that the designed gyroklystron amplifier can produce about 35 dB gain, 800 MHz bandwidth and 100 kW peak output power with power conversion efficiency of 23. 8% for a beam with 4% axial velocity spread.

A high power Gyrotron Traveling-Wave Amplifier(Gyro-TWT) operating in the low-loss TE01 mode has been designed and demonstrated. The gyro-TWT consists of a double-anode magnetron injection gun(MIG), TE01 mode interaction circuit, a 36mm diameter collector, and a three disk sappire output window. A double-anode magnetron injection gun is designed to operate at 70 kV and 10A using the EGUN trajectory code and particle in cell program MAGIC. The electron beam with v⊥/vz =1.0 has a predicated axial velocity spread of 3-5%. The TE01 mode interaction circuit is made up of a section of alternating metal and lossy ceramic (BeO+TiO2) followed by a unloaded, metal-walled output region. The lossy property of the periodically loaded ceramic relieves the worries of the potential Bragg resonance arising from the periodicity of the interaction circuit, bring high attenuation to the potential competing mode, and enhances the stability of a gyro-TWT. The nonlinear self-consistent simulation code evaluated the operating characteristics of the gyro-TWT amplifier. For an axial velocity spread of Δvz/vz=3%, The predicted peak power is 180kW with -3dB bandwidths1.75GHz.

The design and experiment of a ka-band second harmonic gyroklytron amplifier are reported. The three-cavity 35-GHz second harmonic gyroklystron operates in the TE 021 circular electric mode. Based on the numerical simulation, a three-cavity, second harmonic gyroklystron amplifier prototype has been fabricated. Experiments show a peak output power of 212 kW at 35 GHz with a 3-dB bandwidth of 155 MHz (0.44%) when utilizing a 58 kV, 23 A, v ⊥ / v P = 1.45 electron beam from a magnetron injection gun. The efficiency is approximately 16%, and the gain is about 24 dB.

为准确测量脉冲放电电压,提出了固液混合式高压分压器的原理与结构,并进行了标定和实验测试.用简化模型分析了分压器系统的理想响应条件,讨论了两级分压的衰减特性,提出了控制误差的方法.通过负载标定,得到分压器脉冲电压频率响应大于2.9 MHz,最长脉冲宽度40 μs,分压比(或衰减系数)为2.60 kV/V,测量误差小于5％.该高压分压器具有造价低、制作易,同时适于ns到μs级脉冲电压的测量等优点,可以在实验室中得到应用.

In this paper, the design and experiment of the conventional electron beam spreading system for W-band gyrotron oscillator collector is presented. The conventional spread system consists of a magnetic shade and two pairs of coils. The particle-in-cell (PIC) simulation of the collector under the conventional spreading system has been finished. The power density distribution of the electron beam on the collector wall has been measured in the hot test of the gyrotron oscillator.

Mode competition induces non-stationary oscillations during the operation of a gyrotron backward-wave oscillator (gyro-BWO), which severely reduces its tunable bandwidth and output power. Self-consistent nonlinear theory is used to study the modes-competition mechanism of a W-band fundamental TE01 mode gyro-BWO. Tapered non-resonant interaction circuit structure and loading lossy ceramic are employed to suppress the competing modes, as a way of preventing non-stationary oscillation in the circuit. Systematically optimized interaction circuit is capable of suppressing all the competing modes and can stably operate in the fundamental axial mode of the TE01 mode. Calculation indicates that a peak power of 105 kW and a -3 dB tunable bandwidth of 5.4% are attainable. This is meaningful and provides a theoretical foundation for developing broadband millimeter gyro-BWOs in the applications of counter-measure system, non-destructive detection, plasma diagnosis, material processing, and so on.

从理论分析、软件模拟、实验研究等方面研究了氮气介质高气压开关的工作特性.根据强度理论计算所设计并加工的开关的理论压强可达10MPa.对氮气介质高气压开关进行实验,得到在气压范围2,4,6MPa、电极间隙0.1,0.5,1.0mm时,气隙的击穿延时小于14ns,抖动小于1ns;在气压2MPa、电极间隙0.1mm时50％击穿电压约为34kV.与常压空气开关相比较,该开关具有很好的稳定性和绝缘特性.

In this paper, the design of the conventional electron beam spreading system of the gyrotron collector consisted of the magnetic shade and two pairs of coils is presented. The simulation and experiment of the electron beam distribution on the collector wall of the gyrotron applied to the electron spreading system is completed.

The design of a ka-band gyrotron traveling wave (gyro-TWT) amplifier is presented. The gyro-TWT amplifier with a severed structure operates in the fundamental harmonic TE01 circular electric mode. The beam-wave interaction is studied by using a particle-in-cell (PIC) code. The simulations predict that the amplifier can produce an output peak power of over 155 kW, 22% efficiency, 23 dB gain, and a 3 dB bandwidth of 2 GHz for a 70 kV, 10 A electron beam with an axial velocity spread Δvz/vz=5%.

This paper presents the development of a fundamental harmonic TE01 mode W-band gyrotron backward-wave oscillator (Gyro-BWO). The MIG employs a triode configuration to generate a helical electron beam with the current of 1.5 A, the voltage of 30 kV, and a pitch factor of 1.0. A mode-converter free reflective cavity is employed. Simulation reveals that the TE01 mode reflective cavity is capable of generating highest output power up to 10.7 kW with a tunable 3dB bandwidth of about 4 GHz. The present system is aiming at providing a 3kW average power in a tunable bandwidth of 3GHz around 94GHz.

In this paper, a high efficiency circular polarization converter is presented. The TE10 rectangular waveguide mode is converted to the circular polarization TE11 circular waveguide mode, the pill-box window of the vacuum envelope is used. Employing the three-dimensional simulation code, the mode converter is designed and optimized. The results show that the VSWR is 1.17 in the center frequency of 35GHz.

Simulation results of a ka-band high power gyrotron traveling wave amplifier (gyro-TWTA) using the particle-In-cell (PIC) code are reported. The gyro-TWT amplifier with a distributed wall loss structure operates in the fundamental harmonic TE01 circular electric mode. The simulation predicts 135kw output power at ka-band with 19% efficiency, 45 dB gain.

从陶瓷介质材料的临界温度差出发,研究了不同材料的回旋管输出窗的临界热耗散功率。针对TE01,TE11和TE02模式的电磁波通过窗片时发生的不同加热模式进行分析,比较了氧化铝窗片、氧化铍窗片、氮化硼窗片和蓝宝石窗片的热功率承受能力。另外,研究了窗片厚度变化时,不同材料窗片的临界热耗散功率的变化情况。研究表明:蓝宝石和氧化铍窗片表现出较好的热功率耗散能力,其中以蓝宝石窗片最为出色;氧化铝和氮化硼窗片的热功率耗散能力相对较弱;随着窗片厚度的增加,4种材料的临界热耗散功率均有不同程度的变大,其中以蓝宝石和氧化铍窗片更为明显。

根据回旋管的电子回旋脉塞理论,借助于编写的回旋振荡管自洽非线性注-波互作用计算程序,设计出了工作频率94 GHz、工作电压30 kV、工作电流3A的基次谐波连续波单腔回旋振荡管,工作模式为TE02模.设计的回旋振荡管在电压30.0 kV、电流3.0A、速度横纵比1.5的条件下,获得了31.8 kW的输出功率,电子效率约35％.利用粒子模拟仿真软件对设计的回旋管收集极辅助线包散焦系统进行了粒子模拟仿真分析,模拟结果表明:借助于辅助线包散焦系统可以有效缩短回旋振荡管的轴向尺寸,并使回旋管收集极上的电子束功率密度低于500W/cm2;W波段回旋振荡管收集极的热测试验结果表明:利用粒子模拟仿真获得的收集极上的电子束功率密度分布与其试验测量结果比较吻合.