空间电场探测球形传感器表面涂层光电特性研究

Photoelectric Characteristics of Coatings on Spherical Sensor for Space Electric Field Detection

空间电场探测球形传感器是利用卫星平台在空间耦合等离子体电势的敏感部件。球形传感器通常采用加工性能良好、质轻的铝合金材料,表面涂覆导电涂层。而涂层的光电特性会影响电场的测量精度。本文对涂层光电特性对光电子流的影响、对接触电势的影响两个方面进行了理论分析;并就传感器材料铝合金2A12基底、涂层环氧掺碳材料DAG213为研究对象,测量并研究了可表征其光电特性的功函数及其变化;研究结果表明,DAG213涂层表面功函数较铝合金基底有不少于1eV的提升,且标准差有不少于0 eV的降低,说明DAG213涂层的功函数更为均匀,更有利于提高传感器在空间的电场测量精度。

Here,we addressedthephotoelectric characteristics of thecarbon-mixed epoxy coatings,DAG213 deposited on substrate of 2A12 Al alloy.The influence of the coatings on the photoelectron properties,contact potential,and detection accuracy of the spherical sensor for space electric field detection,a sensitive device to couple the plasma potential on board of a GEO satellite platform,was empirically approximated,mathematically modeled,theoretically calculated,and experimentally evaluated by measuring the surface work function distribution with Kelvin probe,before and after the surface modification of 2A12A1 with DAG213 coatings.The results show that the DAG213 coating significantly improves the detection accuracy of the space electric field,simply because the DAG213 coating increased the work function by over 1 eV and reduces the RMS difference of the surface work function profile from 37.99 to 14.7 meV.