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摘要: 基于增材制造的技术特点, 设计完成了适用于3D打印的阴极热子组件模型, 并通过选择性激光熔融技术一体化3D打印完成了直径为3 mm和5 mm的样品, 并对样品展开了相应的后处理工艺研究, 包括去除支撑结构、热子绝缘防护和浸渍发射盐等。结果表明, 新型组件的热子能够将阴极加热至900~1100℃的工作温度范围; 在水冷阳极二极管中测试, 1100℃下阴极拐点发射电流密度达到7.94 A·cm-2。Abstract: The cathode-heater assembly model for 3D printing was designed based on the technical characteristics of additive manufacturing. The samples in the diameters of 3 mm and 5 mm were 3D-printed by selective laser melting; meanwhile, the corresponding post-treatments for the samples were carried out, including the removal of support structure, the insulation protection of heater, and the impregnation of active material. The results show that, the cathode can be heated to the work temperature in range of 900~1100 ℃ by the new heater assembly, and the emission current density at the cathode inflexion can achieved as 7.94 A·cm-2 at 1100 ℃ in water-cooled diode test.
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表 1 加热功率及阴极热子温度
Table 1. Heating powers and the corresponding temperatures of cathode and heater
热子电/V 热子加热功率/W 热子温度/℃ 阴极发射表面温度/℃ 阴极热子温差/℃ 6 12.30 983 830 153 7 16.03 1050 883 167 8 19.28 1129 941 188 9 22.95 1176 987 189 10 26.90 1233 1035 198 11 30.25 1272 1071 201 表 2 新型阴极热子组件的阴极表面能谱分析
Table 2. Energy spectrum analysis of the new type cathode-heater assembly surface
元素 质量分数/% 原子数分数/% O 13.90 59.73 Al 3.36 8.55 Ba 6.19 3.10 W 76.55 28.62 -
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