双阶梯阴极型磁绝缘线振荡器设计与模拟

 结合负载限制型磁绝缘线振荡器（MILO）和渐变型MILO的特点,提出了一种新型双阶梯阴极型MILO。该器件前2个叶片为扼流片，中间3个叶片为主作用叶片,后面1个为提取叶片，在电流发射区与慢波结构径向相对的阴极部分分为3段，形成双阶梯阴极结构。根据Maxwell方程和Floquet定理导出其色散方程，并对其振荡主频作了理论分析。2.5维粒子模拟表明，器件工作频率为1.21 GHz，与理论预测相符，双阶梯的引入，对器件阻抗和振荡频率影响较小。在工作电压458 kV、电流40.5 kA条件下，双阶梯阴极结构将MILO输出功率从2.20 GW提高到2.88 GW，功率转换效率从12.0%提高到15.5%。

Design and simulation of double ladder cathode magnetically insulated transmission line oscillator

As a combination of load-limited MILO and tapered MILO,a double ladder cathode MILO is presented in this paper.This new type of MILO has six vanes,the first two work as the RF chokes,the middle three work as the slow wave structure,and the last one works as a microwave extractor.As a distinguishing feature of the device,its cathode is constructed by three different radii cylinders in the beam emission region.According to Maxwell equations and Floquet's theorem,the dispersion function of TM modes is derived,and its dispersion characteristic is analyzed through numerical calculation.2.5 D particle simulation tells that,the operation frequency of the device is 1.21 GHz which agrees with the theoretical calculation,and the introduction of a double ladder cathode has little influence on the impedance and oscillating frequency of the device.Under a voltage of 458 kV and a corresponding current of 40.5 kA,the double ladder cathode structure advances the output power of the device from 2.20 GW to 2.88 GW,as a result,the power conversion efficiency increases from 12.0% to 15.5%.