低引导磁场下相对论亚纳秒电子束毫米波返波振荡器的粒子模拟

提出了一种Ka波段的相对论亚纳秒电子束毫米波慢波结构,在较低引导磁场情况下,运用粒子模拟(PIC)方法成功地模拟出器件中波束互作用的非线性物理演化过程,得到了一种超辐射状态下的微波辐射,它的产生与波相对于电子束滑移引起的电子束内电子间相互作用有关,辐射微波的峰值功率与电子束总电荷的平方成正比.粒子模拟有利于对超辐射这种束波互作用非线性物理现象的理解,并且对器件的设计有一定的参考价值.

Particle Simulation of Subnanosecond Millimeter Relativistic Backward Wave Oscillator in the Low Guide Magnetic Field Region

Particle simulation results of coherent stimulated radiation from subnanosecond electron bunches moving through a periodic waveguide and interacting with a backward propagating TM 01 wave are presented. The longitudinal guiding magnetic field is 1.8T, the peak power as high as 100 MW for the 300ps pulses at 38GHz. The mechanism of microwave pulse generation was associated with the mutual influence of different parts of the electron pulse due to slippage of the wave with respect to the electrons; The dependence of peak power on the square of the total charge is almost linear, it means that all electrons of e-bunch radiate coherently. This can be interpreted as superradiance.