月基极紫外相机多层膜反射镜

Multilayer Mirrors Used for the Moon-Based EUV Imager

月基极紫外相机用于月球表面对地球等离子体层辐射出的30.4nm谱线进行成像观测,多层膜反射镜是月基极紫外相机的重要光学元件。根据月基极紫外相机技术参数,选择了B4C/Mg,B4C/Mg2Si,B4C/Al,B4C/Si,Mo/Si等材料,对其周期厚度、材料比例、周期数等参数进行优化。计算了以上材料组合在30.4nm的反射率曲线。考虑到月球环境的特殊性和材料的物理化学性质,从中选择出Mo/Si和B4C/Si两种组合,利用磁控溅射进行镀制。Mo/Si和B4C/Si多层膜在30.4nm反射率分别达到15.3%和22.8%。

The EUV imager is used to observe the 30.4 nm radiation of the earth＇s plasmasphere on the lunar surface.The 30.4 nm multilayer is the key optical part of the imager.According to the technical parameters,the B4C/Mg,B4C/Mg2Si,B4C/Al,B4C/Si,Mo/Si and so on were chosen.The period thickness,ratio of the material and the number of the periods were optimized and the reflectivity of those multilayers were calculated.In consideration of the lunar enviro nment,the Mo/Si and the B4C/Si multilayer were deposited by magnetron sputtering coating plant.The reflectivity of Mo/Si and B4C/Si multilayer at 30.4 nm is 15.3% and 22.8% respectively.