基于pseudospark放电产生电子束的Y波段扩展互作用振荡器研究

发布时间：2018-09-12 20:09

【摘要】：近年来,太赫兹辐射因其独有的特性在高数据速率通信、分子光谱、生物光谱、医疗诊断等方面得到广泛应用,但又因其缺乏轻便可靠的太赫兹辐射源而制约了其发展。因此高功率、轻便小型化的太赫兹辐射源受到许多国家的广泛关注和研究。扩展互作用振荡器(EIO)就是一种正处于发展阶段的重要太赫兹辐射源。它是一种集速调管的高功率、高增益与行波管的宽带等优点于一体的电真空高功率源。随着EIO器件向更高的毫米波段及太赫兹波段发展,器件尺寸的缩小,怎样提高器件的功率密度及功率容量成为EIO研究重点之一。在本论文主要内容包括:系统地介绍了太赫兹发展史、现状以及Pseudospark(PS)放电;概述了扩展互作用振荡器的发展、工作原理及现状,并简要概括了本文所选用模型及小信号理论;Y波段EIO器件的设计与优化、仿真结果分析;基于PS放电产生电子束的速度离散对Y波段的EIO器件性能的影响。本论文研究内容及创新点如下:(1)使用PS放电系统代替传统的电子光学系统产生电子束。在没有外加磁场的条件下,PS放电产生的电子束可以实现自我聚焦。不再需要外加磁场,使得整个器件变得更为轻便化小型化。随着器件工作频率的增高,太赫兹范围内工作的EIO器件也会对电子束质量要求更高。而PS放电能产生强流密度、高亮度、纳秒级的轴对称电子束脉冲,其电流密度高达108 A/m2,亮度高达1012 A/m2 rad2。PS放电产生电子束的优良束质正好满足高频率工作EIO的需求。(2)借助高频电磁模拟软件CST及CHIPIC,设计及优化了一款工作在Y波段(工作主频约为283.7GHz)扩展互作用振荡器。在电子束电压为36kV,电子束电流密度达到800A/cm2(电流为0.25A)的情况下,峰值输出功率为1.85kW,电子效率达到10%。(3)PS放电产生的电子束本身具有一定的速度离散,所以为了更好的提高EIO器件的性能,研究了速度离散对EIO器件性能的影响。发现当电子束电流为一定值时,Y波段的EIO在一定的速度离散范围内可以保持稳定且有效的工作状态。在上述最优仿真结果的基础上,速度离散值设定为12.5%时,EIO的峰值输出功率为1.67kW。在电子束电流密度为1kA/cm2,速度离散值设定在0~15%的范围内时,输出功率不低于理想状态电子束输出功率的0.9倍。
[Abstract]:In recent years, terahertz radiation has been widely used in high data rate communication, molecular spectrum, biological spectrum and medical diagnosis because of its unique characteristics. However, its development is restricted by its lack of portable and reliable terahertz radiation sources. Therefore, high-power, portable and miniaturized terahertz radiation sources have received extensive attention and research in many countries. The extended interaction oscillator (EIO) is an important terahertz radiation source in the development stage. It is an electric vacuum high power source with the advantages of high power, high gain and broadband of TWT. With the development of EIO devices to higher millimeter band and terahertz band, and the reduction of device size, how to improve the power density and power capacity of EIO becomes one of the focuses of EIO research. The main contents of this thesis are as follows: the history of terahertz development, current situation and Pseudospark (PS) discharge are systematically introduced, and the development, working principle and current situation of extended interaction oscillator are summarized. The design and optimization of Y band EIO devices based on the model and small signal theory are briefly summarized, and the simulation results are analyzed. The effect of the velocity dispersion of electron beam generated by PS discharge on the performance of Y band EIO devices is also discussed. The main contents and innovations of this thesis are as follows: (1) PS discharge system is used to produce electron beam instead of traditional electron optical system. In the absence of an external magnetic field, the electron beam produced by the discharge of PS can achieve self-focusing. The external magnetic field is no longer required, which makes the whole device more portable and miniaturized. With the increase of the operating frequency, the EIO devices operating in the terahertz range will also require higher electron beam quality. PS discharge can produce strong current density, high brightness, nanosecond axisymmetric electron beam pulse, Its current density is up to 108A / m ~ (2), and its brightness is up to 1012 A/m2 rad2.PS discharge. The excellent beam quality can meet the demand of high-frequency working EIO. (2) with the help of high-frequency electromagnetic simulation software CST and CHIPIC, we design and optimize a Y band ( The main operating frequency is about 283.7GHz) extended interaction oscillator. When the electron beam voltage is 36kV and the electron beam current density is 800A/cm2 (current 0.25A), the peak output power is 1.85kW, and the electron efficiency is 10. (3) the electron beam produced by PS discharge has a certain velocity dispersion. In order to improve the performance of EIO devices, the effect of velocity dispersion on the performance of EIO devices is studied. It is found that the EIO in Y band can maintain a stable and effective working state in a range of discrete velocities when the electron beam current is at a certain value. On the basis of the above optimal simulation results, the peak output power of EIO is 1.67 kW when the discrete velocity is set to 12.5. When the electron beam current density is 1 Ka / cm ~ 2 and the velocity discrete value is set in the range of 0 ~ 15%, the output power is not less than 0.9 times of the ideal electron beam output power.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN752

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