关键词: 空心阴极, 热特性, 辐射传递系数, 温度分布, 热耗散

Abstract:  The hollow cathode commonly serves as an electron source in ion or Hall propulsion systems, and its thermal characteristics exert a great impact on the cathode’s performance and life time. In order to study the temperature distribution and heat consumption power of the operating hollow cathode, a numerical analysis was conducted. The cathode temperature distribution in steady state was solved by combining the fluid calculation (F process) and the heat transfer calculation (HT process), in which both the F process and the HT process provided the input conditions to each other and iterated over again. A temperature measurement test was performed to justify the model’s accuracy. Five measurement points were set on the cathode surface, and the temperatures solved by the calculation were compared with test results. The maximum calculation error is less than 5%, based on which the thermal characteristics were modeled with different cathode structures and materials. The results show that the heat consumption power presents a trend of firstdecreasethenincrease with the cathode changing from a shorter length to a longer one; the heat consumption power increases and the temperature decreases when higher emissivity keeper shell is adopted.

Key words: hollow cathode, thermal characteristics, radiation transfer coefficient, temperature distribution, heat consumption