Multipactor is a resonant nonlinear electron multiplication effect that may occur in high power microwave devices at very low pressures, such as those operating in particle accelerators and satellite subsystems. In this research, multipactor of a rectangular waveguide was analyzed using the commercially available, numerical simulation software “Spark3D.” The electromagnetic wave in the simulation was a TE10 mode-2.85 GHz wave of varying power, fed into the impedance transformer waveguide. At the lowest threshold, multipactor is generated in the minimum height region in the impedance transformer and nowhere else. More precisely, the multipacting electrons have a continuous energy distribution since the emitted secondary electrons carry a random initial velocity distribution. We observed that there are cases where the impact electron energy decreases despite an increase in power due to growing non-resonance of the microwave field and electron oscillations, resulting in not only two threshold points where secondary emission yield (SEY) = 1 but several more. As a consequence, it was uncovered that when the average SEY in the highest field region is close to or less than one, multipactor may be caused in a lower field region where the SEY is effectively higher than one. The numerical results are compared with data from the experiment. While there is some deviation between the thresholds obtained from Spark3D and the experiment, the results at higher power levels are consistent with the experiment in the view of the SEY for each power level.

中文翻译：

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使用 Spark3D 软件分析矩形波导中的多路复用器

Multipacor 是一种谐振非线性电子倍增效应，它可能发生在极低压力下的高功率微波设备中，例如在粒子加速器和卫星子系统中运行的设备。在这项研究中，使用市售的数值模拟软件“Spark3D”分析了矩形波导的多路复用器。模拟中的电磁波是功率变化的 TE10 模式 2.85 GHz 波，馈入阻抗变换器波导。在最低阈值处，在阻抗变换器中的最小高度区域生成多路复用器，而不会在其他任何地方生成。更准确地说，由于发射的二次电子带有随机的初始速度分布，因此多重电子具有连续的能量分布。我们观察到，在某些情况下，尽管由于微波场的非共振和电子振荡的增加而导致功率增加，但碰撞电子能量会降低，这不仅导致二次发射产率 (SEY) = 1 的两个阈值点，而且还有更多. 结果发现，当最高场区域中的平均 SEY 接近或小于 1 时，可能会在 SEY 有效高于 1 的较低场区域中引起多聚体。将数值结果与实验数据进行比较。虽然从 Spark3D 获得的阈值与实验之间存在一些偏差，但从每个功率级别的 SEY 来看，更高功率级别的结果与实验一致。