低能质子对卫星热控涂层太阳吸收率的影响

空间低能质子由于沉积能量在表层对卫星外露热控涂层太阳吸收率参数有较大影响,文章首次对地球同步轨道卫星6种热控涂层进行低能质子辐照试验研究,试件是S781有机白漆、SR107-ZK有机白漆、ACR-1有机白漆、OSR二次表面镜、F46二次表面镜和Kapton二次表面镜。试验采用能量48keV的质子,在真空条件下累积辐照360h,累计注量达到2×10~(15)p/cm~2。在辐照过程中原位测量热控涂层的太阳吸收率参数。这些热控涂层的太阳吸收率参数都有不同程度的明显上升。其中,有机白漆类热控涂层的太阳吸收率参数上升最快,其次是塑料薄膜类热控涂层(F46二次表面镜和Kapton二次表面镜),最稳定的是玻璃类热控涂层(OSR二次表面镜)。对试验前后试件的SEM分析和XPS分析表明,热控涂层中的颜料结构和聚合物结构在辐照下发生变化,形成不饱和链发色团和色心,使原来透明聚合物和高反射的颜料对太阳光产生吸收,从而引起热控涂层太阳吸收率参数上升。

Low Energy Proton Effects on Solar Absorptance of Thermal Control Coatings

The low energy proton in space radiation environment results in solar absorptance increase of external thermal control coatings since low-energy proton deposits all its energy at surface.The experiments of low proton irradiation test was performed for six types of thermal control coating as S781 organic white paints,SR107-ZK organic white paints,ACR-1 organic white paints,OSR second-surface mirror,F46 second-surface mirror,and Kapton second-surface mirror. The 48keV proton irradiates theses samples for about 360 hours under vacuum condition, accumulated flux to 2×10~(15) p/cm~2.The in-situ measurements for solar absorptance were carried out during irradiation.All six thermal control coatings increase in different extent.The organic white paints are the highest one.Two polymer film second-surface mirrors are the second.The OSR sec- ond-surface mirrors is the best stable in solar absorptance.SEM and XPS analysis shows that the structure of ZnO pigments,polymerized film and bond are degraded during irradiation of low- energy protons,making high reflective pigment and transparent polymer dark and opaque,causing increases of solar absorptance of thermal control coatings.