Murakami Go, Sakai Kouichi, Homma Tatsuro, Yoshioka Kazuo, Yoshikawa Ichiro, Ichimaru Satoshi, Takenaka Hisataka
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
Rev Sci Instrum. 2011 Mar;82(3):033106. doi: 10.1063/1.3560136.
We briefly report on the performance and stability of periodic multilayer mirrors containing Y(2)O(3) and Al layers designed for normal incidence reflection at the He-II emission line (30.4 nm). We found that Y(2)O(3)∕Al multilayer coatings had higher reflectivity (24.9%) at 30.4 nm and significantly lower reflectivity (1.3%) at 58.4 nm than the conventional coatings such as Mo∕Si. Furthermore, we investigated the temporal stability of the Y(2)O(3)∕Al multilayer coatings. Our sample was kept under vacuum, dry N(2) purge, and normal atmosphere for over three months, and there were no measurable changes in the reflectivity. These results suggest that we can use Y(2)O(3)∕Al multilayer coatings as standard mirrors for the He-II radiation.
我们简要报告了含Y(2)O(3)和Al层的周期性多层镜的性能和稳定性，这些多层镜设计用于在氦-II发射线（30.4纳米）处进行正入射反射。我们发现，Y(2)O(3)∕Al多层涂层在30.4纳米处具有较高的反射率（24.9%），而在58.4纳米处的反射率（1.3%）明显低于诸如Mo∕Si等传统涂层。此外，我们研究了Y(2)O(3)∕Al多层涂层的时间稳定性。我们的样品在真空、干燥氮气吹扫和正常大气环境下放置了三个多月，反射率没有可测量的变化。这些结果表明，我们可以将Y(2)O(3)∕Al多层涂层用作氦-II辐射的标准镜。
