电子束撞击介质表面引发的带电现象分析

Surface charging analysis induced by electron beam impact dielectric

现有关于介质微波部件微放电的相关研究多从谐振条件及出射电子产额方面出发分析微放电发生原因及其抑制方法,而很少分析航天器表面电位对于微放电发生的影响。文章对碰撞电子与介质表面相互作用后二次电子发射特性进行综合分析;重点研究了不同介质表面初始电位情况下,恒定能量的电子束流持续轰击介质表面时介质表面电位及电子束流碰撞能量的变化趋势;并对稳定后的电子束流碰撞能量和介质表面电位进行了理论计算,计算结果表明系统平衡状态时的表面电位受初始电子能量及第二临界能量影响有明显改变。此外,文章探究了单一能量及连续能量入射介质表面时表面带电对于二次电子发射的影响,研究表明:带有电位的表面会使临界能量发生偏移量为-e的相对偏移;对于连续能量的入射电子束,介质表面带电会很大程度上改变入射电子束的能量范围,从而影响微放电发生的风险。

For existing multipactor occurred in dielectric microwave components, more attention is paid to multipactor source and suppression from the aspect of resonance and emitted electron yield,while the study about influence of surface potential on multipactor is rarely reported. Secondary electron emission characteristics were analyzed. Final surface potential and electron impact energy were emphatically studied when electron beam with constant energy sostenuto impacted the dielectric surface with various initial surface potential.Surface potential and electron impact energy were calculated when the system became stable.Calculated data indicates that steady state of the system is remarkably influenced by primary energy and the second critical energy. The influence of surface potential on secondary electron emission was systematically studied when electrons with single and continuous energy impacted the dielectric surface.An—eΦ energy shifting of critical energy is revealed when surface potential is Φ. For electron beam with continuous incident energy,impact energy range is dramaticlly effected by surface potential of the dielectric,and the risk of multipactor is further influenced.