Jiang Hui, He Yan, He Yumei, Li Aiguo, Wang Hua, Zheng Yi, Dong Zhaohui
Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Zhangheng Road 239, Pudong District, Shanghai 201204, People's Republic of China.
J Synchrotron Radiat. 2015 Nov;22(6):1379-85. doi: 10.1107/S1600577515017828. Epub 2015 Oct 17.
Ru/C multilayer monochromators with different periodic thicknesses were investigated using X-ray grazing-incidence reflectivity, diffuse scattering, Bragg imaging, morphology testing, etc. before and after cryogenic cooling. Quantitative analyses enabled the determination of the key multilayer structural parameters for samples with different periodic thicknesses, especially the influence from the ruthenium crystallization. The results also reveal that the basic structures and reflection performance keep stable after cryogenic cooling. The low-temperature treatment smoothed the surfaces and interfaces and changed the growth characteristic to a low-frequency surface figure. This study helps with the understanding of the structure evolution of multilayer monochromators during cryogenic cooling and presents sufficient experimental proof for using cryogenically cooled multilayer monochromators in a high-thermal-load undulator beamline.
利用X射线掠入射反射率、漫散射、布拉格成像、形貌测试等方法，对不同周期厚度的Ru/C多层单色器在低温冷却前后进行了研究。定量分析能够确定不同周期厚度样品的关键多层结构参数，特别是钌结晶的影响。结果还表明，低温冷却后基本结构和反射性能保持稳定。低温处理使表面和界面变得光滑，并将生长特性改变为低频表面形貌。本研究有助于理解多层单色器在低温冷却过程中的结构演变，并为在高热负荷波荡器光束线中使用低温冷却的多层单色器提供了充分的实验证据。
