Ignition and Plume Characteristics of Low-Current Cerium and Lanthanum Hexaboride Hollow Cathodes
Ignition and Plume Characteristics of Low-Current Cerium and Lanthanum Hexaboride Hollow Cathodes
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低电流六硼化铈、镧空心阴极的点火和羽流特性
DOI：
10.2514/1.41386
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发表时间：
2010
影响因子：
1.9
通讯作者：
W. Hargus
中科院分区：
文献类型：
--
作者：
D. Warner;R. Branam;W. Hargus
本研究研究了六硼化铈（ceb6）和六硼化镧（LaB 6）作为发射体在6.4 mm直径的空心阴极中用于低功率电力推进应用。介绍并讨论了各阴极的点火性能和羽流行为。两个相同的阴极，除了插入材料，被组装并集成到一个圆柱形阳极配置，没有施加磁场。实验测试了两种孔板几何形状和宽范围的氙流速（1.5-4.5 sccm）和阳极电流（2-6 a）为每个阴极。还研究了在这些条件下阴极性能与保持器打开和关闭。朗缪尔探测器收集羽流数据，包括等离子体密度、电子温度、等离子体势和漂浮势。用示波器监测保持电极和阳极的电压行为。最初，两个阴极成功启动，没有过多的保持电压（<650 V），加热时间（<15分钟），或流量（<4.5 sccm）。LaB 6阴极始终在这些相同的条件下启动。然而，ceb6阴极在一段时间后表现出一些退化，需要更高的流速和更长的加热时间来启动。在阳极电流高达5 A的情况下，两种阴极都表现出理想的（点模式）操作，流速低至1.5 sccm，没有加热器或保持器电源。
This research investigated cerium hexaboride (CeB 6 ) and lanthanum hexaboride (LaB 6 ) as emitters in 6.4-mm-diam hollow cathodes used for low-power electric propulsion applications. Each cathode's ignition performance and plume behavior is presented and discussed. Two identical cathodes, with the exception of the insert material, were assembled and integrated into a cylindrical anode configuration without an applied magnetic field. The experiments tested two orifice geometries and a wide range of xenon flow rates (1.5-4.5 sccm) and anode currents (2-6 A) for each cathode. Also investigated was cathode performance for these conditions with the keeper on and off. A langmuir probe collected plume data to include plasma densities, electron temperature, plasma potential, and floating potential. An oscilloscope monitored the voltage behavior of the keeper electrode and anode. Initially, both cathodes successfully started without excessive keeper voltages (<650 V), heating times (<15 min), or flow rates (<4.5 sccm). The LaB 6 cathode consistently started at these same conditions. However, the CeB 6 cathode demonstrated some degradation after time by requiring higher fiow rates and a longer heating time to start. Both cathodes demonstrated ideal (spot mode) operation for flow rates as low as 1.5 sccm at anode currents as high as 5 A with no heater or keeper power.