【作者】 袁学松；

【导师】 刘盛纲；

【作者基本信息】 电子科技大学 ， 等离子体物理， 2008， 博士

【摘要】 为了发展大功率太赫兹辐射源,本学位论文首先对磁化等离子体填充波导中的电子注、波、等离子体三者互作用进行了详细的理论研究,提出利用双流不稳定性来产生大功率太赫兹辐射。同时对同轴腔双电子注回旋管进行了详细的研究,得出利用同轴腔双电子注回旋管产生大功率太赫兹辐射具有以下一系列的优点:改善模式竞争、提高输出功率、实现双频工作等。1、在研究磁化等离子体填充波导中电子注、波、等离子体三者互作用时,作者采用一种新的处理方法:等效介质法。将等离子体和电子注均考虑成一种特殊的媒质,同时还考虑了电子注与等离子体的表面电流密度。利用这一处理方法计算给出了强流相对论电子注中电磁波的色散特性曲线;同时对磁化等离子体填充波导中注、波、等离子体互作用进行了详细的研究;另外作者还提出利用双电子注之间的双流不稳定性来产生大功率太赫兹波。2、对一种新型的同轴腔双电子注回旋管进行了详细的研究。采用回旋管线性理论研究了同轴腔双电子注回旋管的模式竞争,发现同轴腔双电子注回旋管可以更好地抑制模式竞争。根据回旋管自洽非线性理论,在C++ Builder程序开发软件基础上编写相关的计算程序,该程序可以处理双电子注及同轴内开槽结构。数值计算结果表明,同轴腔双电子注回旋管的注波互作用效率可达到同轴腔单电子注回旋管相同的水平。3、研究发现在同轴腔双电子注回旋管中利用双电子注可以在同一谐振腔中同时激励起两个频率的电磁波,其频率相差l倍（l为谐波次数）,即电子注一对应激励起一次谐波,电子注二对应激励起l次谐波。根据这一原理设计了一只工作频率为一次谐波10GHz、二次谐波20GHz的同轴腔双电子注回旋管,并对这一回旋管进行了详细的理论计算和数值模拟研究,同时还编写相关的同轴腔多模多注非线性模式竞争程序。理论研究、数值计算以及MAGIC粒子模拟均表明该同轴腔双电子注回旋管可以实现双频工作。4、作为同轴腔双电子注回旋管的实验准备,设计了一只工作频率0.22THz、工作模式TE₀₃模的圆柱波导谐振腔回旋管,并对其进行相关的实验测试,测试结果表明所采用的设计方法及工艺流程是正确无误的。同时作者还设计了一只工作频率为0.11THz/0.22THz同轴腔双电子注回旋管。更多还原

【Abstract】 In order to develop the high power Terahertz radiation source, the electron beam-wave interactions in a plasma waveguide immersed in a finite magnetic field are studied. And the coaxial gyrotron with two electron beams （CGTB） is proposed and investigated. The results of numerical calculations and PIC simulation show that CGTB has some distinguished advantages: mode competition is improved; output power is enhanced and it is able to obtain dual frequencies radiation, etc.1. The theoretical study on the electron beam-wave interactions in a plasma waveguide immersed in a finite magnetic field is given in the chapter II, in which both the plasma and the electron beam are considered as special media and the surface current density due to the ripple of the plasma/beam is also calculated. According to this approach, the dispersion figure of an electron beam is obtained; the beam-wave interactions in plasma Cherenkov maser and the two-beam instability in a waveguide filled with magnetized plasma have been studied in detail. The results show that this approach is more accurate and can provide more information. In addition, the two-beam instability in a waveguide filled with magnetized plasma is found to be able to produce high power Terahertz radiation theoretically.2. The coaxial gyrotron with two electron beams is proposed and investigated by the linear theory of CGTB. The results of the numerical calculations show that CGTB have a better performance in mode competition than the coaxial gyrotron with one beam （CGOB）. Besides, the self-consistent nonlinear program is developed on C++ Builder platform, which can deal with two electron beams and the coaxial cavities with corrugated inner conductor. The results of calculations show the beam-wave interaction efficiency of CGTB can reach the same value as that of CGOB.3. The dual frequency operation （DFO） of CGTB has been investigated. In such an operation, one beam works at the first harmonic while another at l^th harmonic. According to this principle, a CGTB operation on the first harmonic （10GHz）, the second harmonic （20GHz） is designed. The results of the numerical calculations and PIC （MAGIC） simulation show that CGTB can obtain high output power at two different frequencies simultaneously. 4. As a preparation for CGTB experiment, the author designs a 0.22THz, TE03 mode gyrotron. The testing results show that the design approach and technics of gyrotron is practicable. In addition the design of a 0.11THz/0.22THz CGTB has been carried out.更多还原