S781白漆电子辐照后光学性能退化的恢复与保护

为了深入认识和抑制航天器材料空间辐照损伤在地面环境中的恢复,在模拟的空间环境下对S781白漆进行了90 keV电子辐照试验.研究了电子辐照后,试样分别在真空环境下、真空室注入空气后和空气中储存几小时后辐照诱发的光谱反射系数和太阳吸收比的变化.结果表明,S781白漆光学性能退化的恢复主要发生于与空气接触的数分钟内.此外,液氮环境对S781白漆的电子辐照损伤和光学性能退化具有保护作用.液氮的保护机制不仅在于它抑制了氧在材料表面的化学吸附,还在于它对辐照诱发缺陷的冻析效应.

Degradation and ground recovery ofoptical pmperties of$781 white paints after electron irradiation damage and its protection technique

To better understand and suppress the ground recovery of the space radiation damage in spacecraft materials, S781 white paint samples were selected to be put under irradiation of 90 keV electrons in a simulated space environment. After that, the radiation-induced spectral reflectance change and the solar absorptance change were measured in the vacuum, then with air fed into the vacuum chamber, the samples were exposed to the air for several hours. The results show that the optical degradation of S781 white paints is mainly recovered in just several minutes under the air exposure. Furthermore, a liquid-nitrogen environment can conserve the electron irradiation damage and the optical degradation of the S781 white paints. The conservation mechanism of the liquid nitrogen may not only from the suppression of the oxygen chemisorption in the surface, but also from the freeze-out effect of the radiation-induced defects.