Hollow cathode heat shield assembly

Abstract

The invention discloses a heat shield component of a hollow cathode. The hollow cathode comprises a cathode tube and an emitter. The heat shield component comprises at least two heat shield pieces and blocking rings. The heat shield pieces and the blocking rings are coaxially sleeved with the cathode tube, and every two adjacent heat shield pieces are separated by one blocking ring. The heat shield pieces can block axial radiative transfer of the emitter. Due to the fact that one blocking ring is arranged between every two adjacent heat shield pieces, heat contact between the heat shield pieces is effectively reduced, heat conduction loss is small, smooth gasflow of the working medium gas is ensured, the oxidation problem of the emitter is solved, the better heat shield effect is achieved, the service life of the emitter of the hollow cathode is prolonged, and the efficiency of the hollow cathode is improved.

Description

technical field [0001] The invention relates to the fields of aerospace electric propulsion technology and low-temperature vacuum electron plasma technology, in particular to a heat shielding assembly of a hollow cathode. Background technique [0002] Hollow cathodes are a key component of xenon ion thrusters, Hall thrusters, or other plasma sources. In the working process of the hollow cathode, the temperature of the emitter (above 1300K) is maintained by relying on the heat generated by the self-sustained gas discharge formed by the inert working gas, so that the emitter can have the ability to emit electrons. Therefore, during the working process of the hollow cathode, it is necessary to continuously supply high-purity inert working gas with the content of oxidizing gas as low as possible, otherwise, the oxidizing impurity gas may interact with the emitter at high temperature, causing emitter poisoning, and the emitter Excessive evaporation will significantly reduce the ...

AI Technical Summary

Problems solved by technology

[0003] In the existing hollow cathodes, the purity of the working fluid gas reaching the surface of the emitter depends on the guarantee of the purity of the gas source. Usually, the content of oxidizing gas impurities in the gas source is required to be extremely low, which significantly increases the cost of the gas source. In addition, in some hollow cathodes, Use a separate purification unit to purify oxidizing gases

In addition, the existing hollow cathode only uses radial heat shielding to suppress the heat dissipation in the circumferential direction of the emitter, and does not shield the axial heat dissipation of the emitter, so that the axial heat dissipation is not suppressed, which affects the efficiency of the hollow cathode.

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