Measuring the atomic scattering factors near the iridium L-edges for the Athena silicon pore optics reflector
Measuring the atomic scattering factors near the iridium L-edges for the Athena silicon pore optics reflector
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测量 Athena 硅孔光学反射器的铱 L 边缘附近的原子散射因子
DOI：
10.1117/1.jatis.7.1.014001
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Uesugi Kentar
中科院分区：
文献类型：
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作者：
Awaki Hisamitsu;Maeda Yoshitomo;Matsumoto Hironori;Svendsen Sara;Bavdaz Marcos;Collon Maximilien;Ferreira Desiree D. M.;Guainazzi Matteo;Hoshino Masato;Ide Shuntaro;Ishibashi Kazunori;Kan Wansu;Miyazawa Takuya;Shimizu Sadayuki;Tamura Keisuke;Uesugi Kentar
未来的高能任务“雅典娜”预计将包括一个焦距为12米的大口径x射线反射镜。镜面要涂上铱和低锌涂层。为了确定x射线望远镜的有效面积，需要能量分辨率小于x射线积分场单位（2.5 eV）的铱原子散射系数。在同步加速器SPring-8光束线上，分别以10和1.5 eV的阶跃测量了覆盖铱的硅孔光学镜面板在9 ~ 15 keV的能量范围内和铱l边附近的反射率。L3、L2和L1边缘分别在11,215、12,824和13,428 eV附近被清晰地检测到。测量到的散射系数比Henke等人报告的相应值小~ 3%，可能是由于铱涂层上存在一层覆盖层，并且与Graessle等人的测量结果一致。反射率的角依赖性表明，铱表面非常光滑，表面粗糙度为0.3 nm。
Athena, a future high-energy mission, is expected to consist of a large aperture x-ray mirror with a focal length of 12 m. The mirror surface is to be coated with iridium and a lowZovercoat. To define the effective area of the x-ray telescope, the atomic scattering factors of iridium with an energy resolution less than that (2.5 eV) of the x-ray integral field unit are needed. We measured the reflectance of the silicon pore optics mirror plate coated with iridium in the energy range of 9 to 15 keV and that near the iridium L-edges in steps of 10 and 1.5 eV, respectively, at the synchrotron beamline SPring-8. The L3, L2, and L1 edges were clearly detected around 11,215, 12,824, and 13,428 eV, respectively. The measured scattering factors were ∼3 % smaller than the corresponding values reported by Henke et al., likely due to the presence of an overlayer on the iridium coating, and were consistent with those measured by Graessle et al. The angular dependence of the reflectivity measured indicates that the iridium surface was extremely smooth, with a surface roughness of 0.3 nm.