在Ku波段低磁场相对论返波管中, 由于阴极发射的角向不均匀性, 产生的微波除了TM01模, 还有主模TE11等其他微波模式。由于目前设计的圆波导耦合器只能测量TM01模式功率, 其他微波模式存在会导致在线微波波形异常, 给在线测量带来困难。本文设计了一种模式抑制器, 其结构由5个腔组成。通过数值模拟和实测结果得出: TM01模在频率14.8~15 GHz衰减小于0.1 dB, 而对其他模式, 如主模TE11模式微波能够全反射。模式抑制器置于相对论返波振荡器(RBWO)与圆波导耦合器之间, 实验观察在线输出微波与辐射场波形一致, 微波功率符合较好。

研究了线圈间距、匝数、个数以及不锈钢套筒对脉冲磁体产生磁场的影响规律。在储能电容和电压不变的前提下，研究结果表明：增加线圈间距会导致磁感应强度降低，磁力线包络增大，但总电流达到峰值时刻减小；增加线圈匝数，峰值电流明显减小，会降低磁感应强度，但有利于抑制磁力线包络；增加并联线圈个数，有利于产生较长的均匀区，但是在供能一定的条件下，磁场强度有所降低，同时总电流达到峰值时刻减小。总体来看，在一定均匀区长度的设计要求下，减少单个线圈匝数，增加并联线圈个数，能够得到磁感应强度更大、均匀性更好的磁场，但要考虑线圈承载电流的能力。另外，不对称的阴阳极金属结构会导致磁场不对称分布，且磁感应强度达到峰值时刻要晚于总电流达到峰值的时刻。

基于CompactRIO嵌入式技术，采用LabVIEW图形化编程开发平台设计了一种应用于高功率微波(HPM)源的控制系统，详细阐述了系统的结构设计和实现方法。控制系统利用不同模块完成过程控制、数据处理、数据采集等多种任务；采用串行通信和光纤传输等技术，实现监控和数据通信，提高系统的运行性能和可扩展性。实验过程中，基于CompactRIO的控制系统工作稳定，测控效果良好，为进一步开展HPM源技术验证试验奠定一定的技术基础。

This paper provides a review of the compact intense electron-beam accelerators (IEBAs) based on liquid pulse forming lines (PFLs) that have been developed at the National University of Defense Technology (NUDT) in China. The history and roadmap of the compact IEBAs used to drive high-power microwave (HPM) devices at NUDT are reviewed. The properties of both de-ionized water and glycerin as energy storage media are presented. Research into the breakdown properties of liquid dielectrics and the desire to maximize energy storage have resulted in the invention of several coaxial PFLs with different electromagnetic structures, which are detailed in this paper. These high energy density liquid PFLs have been used to increase the performance of IEBA subsystems, based on which the SPARK (Single Pulse Accelerator with spark gaps) and HEART (High Energy-density Accelerator with Repetitive Transformer) series of IEBAs were constructed. This paper also discusses how these compact IEBAs have been used to drive typical HPM devices and concludes by summarizing the associated achievements and the conclusions that can be drawn from the results.

为提高热载流子高功率微波探测器的灵敏度和降低环境温度对探测器性能的影响，开展了液氮环境下的热载流子探测器研究。提出了局部使用可阀合金块的BJ-100型热载流子探测器制作工艺，增强了探测器的抗温度冲击能力。测试结果表明，探测器硅片焊接的结合力大于4.9 N，能够承受从常温到液氮的反复温度冲击。利用100 kW微波源开展了热载流子探测器在室温和液氮环境下的灵敏度测试实验，结果表明：探测器输出波形与肖特基二极管检波器输出波形一致；在保持偏置电流相同的条件下，相较于常温环境，探测器在液氮环境下的相对灵敏度提升约20倍，输出电压可达V级。

针对高功率微波对电子设备的安全威胁, 设计了一种双层柱状等离子体阵列对高功率微波进行防护。其中单根等离子体柱的直径为25.4 mm, 长度为600 mm, 等离子体频率与碰撞频率可进行控制。利用搭建的实验测量系统, 研究了微波极化方向、等离子体电子密度、放电单元层数等因素对高功率微波透射衰减的影响。实验结果表明: 当高功率微波未激发等离子体产生非线性效应时, TM极化时的防护效果优于TE极化时的防护效果, 且能量衰减分别可达20.9 dB和14.7 dB; 随等离子体电子密度增大, 微波透射功率减小, 防护效果增强; 由于层间反射作用, 双层等离子体对高功率微波的透射衰减远大于单层等离子体衰减值的两倍。

Research progresses on Cherenkov and transit-time high-power microwave (HPM) sources in National University of Defense Technology (NUDT) of China are presented. The research issues are focused on the following aspects. The pulse-shortening phenomenon in O-type Cerenkov HPM devices is suppressed. The compact coaxial relativistic backward-wave oscillators (RBWOs) at low bands are developed. The power efficiency in M-Type HPM tubes without guiding magnetic field increased. The power capacities and power efficiencies in the triaxial klystron amplifier (TKA) and relativistic transit-time oscillator (TTO) at higher frequencies increased. In experiments, some exciting results were obtained. The X-band source generated 2 GW microwave power with a pulse duration of 110 ns in 30 Hz repetition mode. Both L- and P-band compact RBWOs generated over 2 GW microwave power with a power efficiency of over 30%. There is approximately a 75% decline of the volume compared with that of conventional RBWO under the same power capacity conditions. A 1.755 GHz MILO produced 3.1 GW microwave power with power efficiency of 10.4%. A 9.37 GHz TKA produced the 240 MW microwave power with the gain of 34 dB. A 14.3 GHz TTO produced 1 GW microwave power with power efficiency of 20%.

为研究发光等离子体对高功率微波的防护性能, 建立了一维条件下等离子体与高功率微波相互作用的物理模型, 并采用数值仿真得到了不同条件下的微波透射效果, 分析了发光等离子体对高功率微波的防护性能。随后, 实验研究了双层柱状等离子体阵列对6 GHz高功率微波脉冲的透射效果, 实验结果与仿真结果相符, 说明高功率微波的入射使等离子体产生了非线性效应。实验结果还表明, TE极化时的防护效果要优于TM极化时的防护效果; 等离子体击穿场强阈值随电场作用空间的增大而减小; TE极化时等离子体对高功率微波脉冲的屏蔽效能最高可达13 dB, 且随入射功率的增大而进一步增大。

高功率微波(HPM)电磁脉冲对引信辐照实验的数据分析是研究其电磁效应中的一个重要问题，数据分析的主要困难在于HPM电磁效应数据的高维复杂性。通过聚类算法设计，采用模糊C均值聚类(FCM)算法对某无线电引信的高功率微波电磁效应数据进行分析处理，利用其类内相似和类间相异的原则，经迭代运算，实现HPM对无线电引信效应数据的脉宽、峰值功率、功率密度等参数间的识别和分类。结果表明：采用FCM算法能够得到HPM对某引信的最佳聚类中心，即致使引信失效的最佳干扰阈值，证明了算法的有效性。