航天器介质材料深层充放电实验与数值模拟

空间辐射环境中高能电子诱发的介质材料深层充放电效应是威胁航天器安全的重要因素之一. 本文采用不同束流强度的电子枪电子, 研究了不同厚度的聚酰亚胺薄膜的深层充电过程; 利用Sr90放射源电子模拟GEO轨道高能电子环境, 研究了在其辐照下聚甲醛树脂和聚四氟乙烯材料的表面电位变化; 实验观测了深层放电产生的电流脉冲和电场脉冲. 提出了深层充电模型, 较好地模拟了实验测量结果, 并且分析了深层充电平衡电位和平衡时间随电子束流强度和介质电阻率的变化规律. 实验和数值模拟结果初步揭示了深层充放电效应的特征及规律, 表明深层充电现象随着电子束流强度和介质电阻率的增加而趋于明显, 介质电阻率是影响深层充电平衡电位和平衡时间的主要因素. 

Experimental Research and Numerical Simulation on Deep Charging for Spacecraft Dielectrics

Deep charging effect caused by high-energy electron irradiation is one of the key factors threatening spacecraft safety under the environment of space radiation. This paper compares the deep charging progress of different thickness polyimide films under different electron beam intensity, simulates the GEO orbit radiation environment with Sr90 radioactive source, and studies the charging progress of Delrin and Teflon under its radiation. This paper also presents a new model, which simulate the experiment results. It also analyzes the deep charging equilibrium potential and time with different electron intensity and dielectrics resistance. It shows that deep charging effect becomes more serious with increasing electron beam intensity and dielectrics resistance, and the time to reach charging equilibrium is mainly affected by dielectrics resistance.