Hollow cathode researches used to focus on the inner cavity or downstream plume, however, rarely on the gap between the throttling orifice plate and the keeper plate (T-K gap), which was found to impact the self-sustaining margin of hollow cathode discharge in this paper. Near the lower margin, the main power deposition and electron emission and ionization regions would migrate from inner cavity and downstream plume to the T-K gap, in which case, the source and destination of each mA current therein matter for the self-sustaining capability. Changing the metal surfaces in the T-K gap with emissive materials proved effective in lowering the lower margin by supplementing auxiliary thermionic emission, compensating electron loss on cold absorbing walls and suppressing discharge oscillations. By doing so, the lower margin of a 4 A hollow cathode was lowered from 1 to 0.1−0.2 A, enabling it to couple with low power Hall thruster without extra keeper current.

中文翻译：

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外部电子发射对空心阴极放电自持裕度的影响

空心阴极研究过去通常集中在内部空腔或下游羽流上，但是很少关注节流孔板和保持板之间的间隙（TK间隙），这会影响空心阴极放电的自持裕度。纸。在下边缘附近，主要的功率沉积，电子发射和电离区域将从内腔和下游羽流迁移到TK间隙，在这种情况下，其中每个mA电流的源极和目的地都具有自我维持能力。通过补充辅助热电子发射，补偿冷吸收壁上的电子损失并抑制放电振荡，事实证明，使用发光材料改变TK间隙中的金属表面有效降低了下限。通过这样做，