星载遥感仪器太阳漫透射板紫外辐照特性

Vacuum Ultraviolet Radiation Characteristics of Diffuser in Spaceborne Remote Sensing Instruments

空间遥感仪器的漫透射板受太阳真空紫外辐照而导致的半球透射率变化将影响仪器在轨辐射定标结果。分析了太阳紫外辐射光谱特点及漫透射板在轨工作的紫外辐照剂量，利用标准氘灯作为光源模拟太阳115～200nm的紫外光谱，在特定距离下对紫外熔石英漫透射板进行了辐照实验。太阳等效紫外辐照48h后，熔石英漫透射板半球透射率在250～1000nm波段产生了不同程度的衰减，其中，紫外波段半球透射率衰减程度略高，250nm处衰减约为3％，近红外波段衰减程度略低，i000nm处衰减约为I％，对漫透射板进行清洗后，半球透射率基本恢复到最初状态。实验结果初步表明，漫透射板表层污染是引起半球透射率衰减的主要因素，该结果将对空间遥感仪器太阳漫透射板防护、在轨定标与衰减修正具有重要意义。

The hemisphere transmittance of transmission diffusers in space remote sensing instruments changes because of the solar vacuum ultraviolet radiation, which will affect the on orbit calibration result of instruments. The characteristics of solar ultraviolet radiation spectra and the UV irradiation dose are analyzed when diffusers are on orbit, a standard deuterium lamp is used as the light source for solar ultraviolet spectrum simulation at 115 ~200 nm, the fused quartz diffuser is irradiated at a specific distance. After 48 h solar ultraviolet irradiation, the fused silica diffuser＇s hemisphere transmittance in 250~ 1000 nm decrease, the degradation at 250 nm is about 3%, in the change near-infrared wavelength is less than that in ultraviolet, and the degradation at 1000 nm is about 1%, after the diffuser is washed, the hemisphere transmittance returns to the original value. The test results show contamination that on the diffuser is a major factor for the hemisphere transmittance degradation, the result is very important for transmittance diffuser protection, on-orbit calibration and degradation correction.