30.4 nm波长处Mg基多层膜反射镜

Multilayer Film Reflective Mirror at 30.4 nm

太阳光谱中重要的He-Ⅱ谱线(波长30.4 nm)的观测对于研究太阳活动和日地空间环境具有重要意义,实现空间极紫外太阳观测需要采用多层膜作为反射元件。研究了工作在30.4 nm的Mg基多层膜。以反射率最高为评价函数设计了多层膜,采用直流磁控溅射技术制备了SiC/Mg,B_4C/Mg和C/Mg多层膜,用X射线衍射仪测量了多层膜的结构。研究表明虽然B_4C/Mg多层膜理论反射率最高,但实际制备结果显示,SiC/Mg多层膜的成膜质量最好,反射率最高。同步辐射反射率测量表明:在入射角10°时实测的SiC/Mg多层膜反射率为44.6%。

Observation of the He-II spectrum at the wavelength of 30.4 nm, a key spectrum in solar spectrum, is of great significance in investigating solar activity and space environment. Multilayer film reflective mirrors are usually adapted in solar observation at extreme ultraviolet （EUV） wave range. Reflection at the wavelength of 30.4 nm of the multilayer films composed of Mg is studied. The multilayer film is designed using evaluation function expressing as highest refiectivity. SiC/Mg, B4C/Mg, C/Mg multilayer films are fabricated by using direct current （DC） magnetron sputtering, and the multilayer structures are measured using X-ray diffractometer. The multilayer mirror of B4C/Mg has highest reflectivity in theory but SiC/Mg multilayer film has the best quality and the highest reflectivity in practice. The reflectivity of SiC/Mg multilayer mirror was measured by the reflectometer in synchrotron radiation laboratory. At incidence angle of 10°, the reflectivity is 44.6 %.