航天器介质放电脉冲频谱特征实验研究

空间电子辐射环境下,航天器介质的充放电效应是威胁航天器安全的重要因素.介质放电现象除与材料参数及构型相关外,还与空间电子环境密切相关.本文通过电子枪和Sr⁹⁰放射源在地面实验装置上模拟空间电子辐照环境,测试了环氧树脂、聚四氟乙烯、聚酰亚胺等常见空间材料在不同温度、不同电子能量和电子束流强度影响下的放电脉冲,并对放电电流脉冲和电场脉冲进行频谱分析.实验分析结果表明,介质材料的放电电流脉冲频谱具有明显的单峰结构,该峰值与材料厚度和入射电子能量相关,但受材料温度和辐照束流强度影响不大.

Experimental Study of Frequency Spectrum Characteristics in Spacecraft Dielectric Discharging

Deep dielectric charging and discharging effect is one of the key factors threatening the spacecraft safety. Besides the dielectric and its grounding configuration, deep dielectric discharging is also affected by the electron environment in space. The space dielectrics such as FR4, Teflon and Polyimide were tested in a simulated space radiation environment on ground, and their discharging currents and electrical field pulses were recorded. By analyzing frequency spectrum characteristics of the discharging transients and the effect of dielectric temperature, electron energy and electron beam intensity, a peak frequency in discharging current was discovered. The result shows that the peak frequency varies with the dielectric thickness and electron energy, while no obvious change was observed at different beam intensities or temperatures.