回旋管同轴谐振腔模式的选择

摘要

In order to study the working mode selection mechanism of gyrotrons, this paper investigates mode selective properties of three kinds of gyrotron cavities, i.e. cylindrical open cavity, coaxial cavity with smooth insert and coaxial cavity with corrugated insert, and further discusses the mode competition phenomenon in these cavities. Through the calculation of dispersive curves of coaxial waveguide, it is determined that coaxial cavities can rarefy the mode spectrum and reduce the competing action of some high-order modes, compared with the cylindrical open cavity, enabling stable single mode operation of gyrotron. Finally, the numerical calculation of dispersion characteristics of a coaxial gyrotron in the KIT(Karlsruhe Institute of Technology) is presented, and the results indicate that the coaxial cavity with corrugated insert is more suitable for high-order working modes than the one with smooth insert.%为了研究回旋管工作模式的选择机理,分析了圆柱波导开放式谐振腔、光滑同轴谐振腔和纵向内开槽同轴谐振腔相应波导的色散特性,进而研究了这些谐振腔内模式竞争的问题.对同轴结构波导色散方程作了相应的数值计算,结果表明,同轴谐振腔利用自身色散曲线与谐振腔内外半径比值的数值关系,能够使在开放式谐振腔内无法工作的高阶模式在其内部稳定工作.最后,以德国卡尔斯鲁厄理工学院(KIT)研制的同轴回旋管为例,进行了相应的分析计算,结果表明纵向内开槽同轴谐振腔相对于光滑同轴谐振腔更适合高阶模式的稳定工作.