电子辐照条件下真空度对介质材料表面电位衰减特性的影响

Effect of Vacuum Degree on Surface Potential Attenuation Characteristics of Dielectric Materials Under Electron Irradiation

为研究航天器介质材料表面电位衰减特性和环境真空度的关系,利用航天器带电地面模拟实验设备对聚酰亚胺和聚四氟乙烯介质材料分别充电到同一电位值,然后关闭电子枪,用电位计测量介质材料表面电位在不同真空度条件下的衰减曲线,并分析电位衰减的途径。结果表明:介质材料所处环境的真空度对电位衰减特性有显著影响,真空度越低,则介质材料表面电位衰减速度越快,且在一定的时间段内其电位衰减效率随真空度的增大而减小,真空度越大则介质材料的等效表面电阻率越大,电荷的衰减主要通过介质材料的表面和内部消散实现,研究介质材料表面电位衰减特性对航天器静电防护具有一定的指导意义。

In order to study the relationship between the surface potential attenuation characteristics of spacecraft dielectric material and the environmental vacuum degree. The polyimide and PTFE dielectric materials were charged to the same potential value respectively using the spacecraft charging simulation equipment on the ground, then close the electron gun, the attenuation curves of the surface potential of the dielectric material under different vacuum degrees were measured by potentiometer, and the potential attenuation ways were analyzed. The results show that the environment vacuum degree of dielectric mate- rial has a significant effect on the potential attenuation characteristics, the lower the vacuum degree, the faster the surface potential attenuation rate, and the potential attenuation efficiency decreases with the increase of the vacuum degree in a certain period of time, the greater the vacuum degree, the greater the equivalent surface resistivity of the dielectric material, the attenuation of charges mainly dissipates through the surface and internal of dielectric material. Studying the surface potential attenuation character- istics of dielectric material has some guiding significance for the electrostatic protection of spacecraft.