航天器微波部件微放电诱导低气压来源分析

Source analysis of multipactor-induced low-pressure gas of microwave component in spacecraft

航天器微波部件低气压放电效应是威胁航天器电子设备安全运行的一种特殊效应,而部件材料表面吸附气体脱附后为低气压放电提供了必要的条件。首先对比了微放电与低气压放电的区别,阐述了低气压放电破坏效应的产生根源。通过理论分析与计算,对比了热效应和电子轰击效应对不同键能吸附气体的脱附效率。结果发现,热致脱附主要造成低键能物理吸附气体的解吸附,电子轰击效应可造成高键能的化学吸附气体的解吸附。阐明了由二次电子倍增引起的电子诱导解吸附过程是星载微波部件内低气压环境的主要形成原因。最后讨论了通过部件材料表面处理及提高二次电子倍增阈值的低气压放电效应抑制方法。

The low-pressure discharge effect of microwave components is a special effect threatening the safety of space electronic components.The low pressure environment inside the component after the desorption of the adsorbed gas from the component material provides the necessary conditions for low pressure discharge.Firstly,the difference between the multipactor and the low-pressure discharge was compared,and the root cause of the destructive effect of low-pressure discharge was described.Through theoretical analysis and calculation,the desorption efficiencies of thermal and electron bombardment effects on adsorbed gases with different bond energies were compared.It is found that thermogenic desorption mainly causes the desorption of physiosorbed gases with low bond energy,and that the electron bombardment effect can cause the desorption of chemisorbed gases with high bond energy.It was elucidated that electron-induced desorption processes caused by secondary electron multiplication are the main reason for the formation of the low-pressure environment inside the on-board microwave components.Finally,the method of suppressing the low-pressure discharge effect by surface treatment of component materials and increasing the threshold of secondary electron multiplication is discussed.