Abstract A hollow cathode is an efficient electron source in the self-heating mode utilizing the discharge power. However, in sub-ampere currents, it needs keeper power to maintain the thermionic electron discharge, which could decrease the thrust efficiency. To address this problem, we propose using a microwave cathode, which is based on the flight model of a microwave ion thruster neutralizer cathode, as an alternative to a hollow cathode. First, we redesigned the magnetic field of a microwave cathode discharge chamber and tested it in the diode mode configuration. The electron emission current is doubled compared to the original performance. Next, we coupled the improved microwave cathode with a 200-W class Hall thruster and compared the characteristics and performance with a hollow cathode. We confirmed that the magnetic field polarity affects the ignition characteristics. We measured the thrust by an inverted thrust stand, the ion energy distribution functions by a retarding potential analyzer, and the beam profiles by an ion collector. The thrust and thrust efficiency are equivalent for both types of cathode. The specific impulse is 10% higher in the case of the microwave cathode. Since the potential difference between the microwave cathode and ground rapidly increased at currents above 600 mA, this could be taken to be the trade-off point against the hollow cathode.

中文翻译：

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与空心阴极相比，微波阴极在 200 W 霍尔推进器中的应用

摘要 空心阴极是一种利用放电功率自热模式的高效电子源。然而，在亚安培电流下，它需要保持电源来维持热电子放电，这会降低推力效率。为了解决这个问题，我们建议使用基于微波离子推进器中和器阴极飞行模型的微波阴极作为空心阴极的替代品。首先，我们重新设计了微波阴极放电室的磁场，并在二极管模式配置下对其进行了测试。与原始性能相比，电子发射电流增加了一倍。接下来，我们将改进的微波阴极与 200 W 级霍尔推进器相结合，并将其特性和性能与空心阴极进行了比较。我们确认磁场极性会影响点火特性。我们通过倒置推力台测量推力，通过阻滞电位分析仪测量离子能量分布函数，并通过离子收集器测量光束轮廓。两种类型的阴极的推力和推力效率是相同的。在微波阴极的情况下，比冲高出 10%。由于微波阴极和地之间的电位差在高于 600 mA 的电流下迅速增加，因此这可以作为与空心阴极的权衡点。两种类型的阴极的推力和推力效率是相同的。在微波阴极的情况下，比冲高出 10%。由于微波阴极和地之间的电位差在高于 600 mA 的电流下迅速增加，因此这可以作为与空心阴极的权衡点。两种类型的阴极的推力和推力效率是相同的。在微波阴极的情况下，比冲高出 10%。由于微波阴极和地之间的电位差在高于 600 mA 的电流下迅速增加，因此这可以作为与空心阴极的权衡点。