磁绝缘线振荡器阴极烧蚀与电压波形的关系研究

通过粒子模拟和实验研究相结合的方法,研究了磁绝缘线振荡器的阴极烧蚀与输入电压波形的关系,找到了造成阴极烧蚀的根本原因,给出了电子束回轰阴极的清晰图像,并通过对低阻抗加速器平台输出电压波形的调整,抑制了反向电压,解决了器件的阴极烧蚀问题.研究结果表明:在正向电压作用下已经发射出来的电子束在超过一定幅度的反向电压作用下发生反向运动并回轰阴极,产生反向电流并造成器件阴极的烧蚀,因此注入电压下降沿之后的反向电压是引起磁绝缘线振荡器的阴极烧蚀的最根本因素.

Relation analysis between cathode ablation and voltage for a magnetically insulated transmission line oscillator

Through the particle-in-cell simulation and experimental investigation, the relation between the cathode ablation and the input voltage waveform of a magnetically insulated transmission line oscillator (MILO) is analyzed. And the key factor that results in the cathode ablation is found. The figures and process that the electron beam bombards back the cathode are obviously presented. By waveform adjustment of the low impedance accelerator, the reverse voltage of the input voltage to MILO is restrained, and the cathode ablation problem of the MILO driven by the low impedance accelerator is solved. Analysis results show that the electron beam which has been hauled from the cathode by the right direction voltage moves back, which the reverse voltage with adequate amplitude driven, and the beam bombards back the the cathode. The reverse current is formed and the cathode of the MILO device is ablated. Therefore, the reverse voltage immediately following the down slope of the input voltage is a key factor.