C波段磁绝缘线振荡器的数值模拟

 利用2维半全电磁PIC程序进行数值模拟，设计了一种C波段磁绝缘线振荡器。该振荡器在阴极电子发射起点加圆环,控制此处电子束的发射密度，来减少电子能量的损耗，改善束-波互作用；逐渐加大慢波结构的后两个叶片的内半径，增大微波群速度，便于谐振腔中的能量输出，提高微波输出效率；采用两个扼流片有效地阻止了微波功率向二极管区泄漏，相应减小了器件的尺寸。当外加电压为430 kV、束流46 kA时，饱和后输出微波平均功率2 GW，频率3.51 GHz，功率转换效率10%。

Numerical simulation of an improved type C-band MILO

Using a 2.5 dimensional fully electromagnetic particle-in-cell(PIC) code,a new type of MILO was designed.A circle is placed at the launch point to improve the interaction between the electron beam and the fields supported by the slow wave structure,thus to control the beam current density at the launch point,and to minimize the loss of the electron beam energy.The inner radii of the extractor vanes are slightly larger than those of other SWS vanes,which increases the axial group velocity and enhances the microwave output power and efficiency.Implementation of two RF choke vanes stops the leakage of microwave pulse power toward the diode,and makes the device more compact than the conventional MILO.High power microwave is generated from the device with an average output power of 2 GW,a frequency of 3.51 GHz and an efficiency of 10%.