Atmospheric coherent X-ray diffraction imaging for in situ structural analysis at SPring-8 Hyogo beamline BL24XU.
Atmospheric coherent X-ray diffraction imaging for in situ structural analysis at SPring-8 Hyogo beamline BL24XU.
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DOI：
10.1107/s1600577518006410
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发表时间：
2018-07
影响因子：
2.5
通讯作者：
Y. Takayama;Yuki Takami;Keizo Fukuda;T. Miyagawa;Y. Kagoshima
中科院分区：
文献类型：
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作者：
Y. Takayama;Yuki Takami;Keizo Fukuda;T. Miyagawa;Y. Kagoshima
相干 X 射线衍射成像 (CXDI) 是一种很有前景的技术，可用于以纳米分辨率对微米级非晶态样品进行无损结构分析。本文介绍了在 SPring-8 Hyogo 光束线 BL24XU 开发的大气 CXDI 系统，用于原位结构分析，并设计用于 8 keV 光子能量的实验。这种相对较高的 X 射线能量使得实验能够在周围大气条件下进行，这有利于在自然状态下观察样品。根据基于菲涅尔-基尔霍夫衍射公式的波传播计算，优化了针孔狭缝光学器件的照明条件，使 X 射线具有平面波前和约 1 × 1010 光子/16 µmø(FWHM)/s 的高光子通量。这项工作通过以 29.1 nm 的分辨率可视化亚微米大小的胶体金颗粒的内部空隙，展示了大气 CXDI 系统的成像性能。通过在系统中安装自制的湿度控制装置，还进行了受控湿度下单个大孔二氧化硅颗粒的 CXDI 实验。根据湿度变化对衍射图样的变化进行了原位观察，并在 5.2% RH（相对湿度）和 82.6% RH 下以 133 nm 和 217 nm 的分辨率重建了投影电子密度图。
Coherent X-ray diffraction imaging (CXDI) is a promising technique for non-destructive structural analysis of micrometre-sized non-crystalline samples at nanometre resolutions. This article describes an atmospheric CXDI system developed at SPring-8 Hyogo beamline BL24XU for in situ structural analysis and designed for experiments at a photon energy of 8 keV. This relatively high X-ray energy enables experiments to be conducted under ambient atmospheric conditions, which is advantageous for the visualization of samples in native states. The illumination condition with pinhole-slit optics is optimized according to wave propagation calculations based on the Fresnel-Kirchhoff diffraction formula so that the sample is irradiated by X-rays with a plane wavefront and high photon flux of ∼1 × 1010 photons/16 µmø(FWHM)/s. This work demonstrates the imaging performance of the atmospheric CXDI system by visualizing internal voids of sub-micrometre-sized colloidal gold particles at a resolution of 29.1 nm. A CXDI experiment with a single macroporous silica particle under controlled humidity was also performed by installing a home-made humidity control device in the system. The in situ observation of changes in diffraction patterns according to humidity variation and reconstruction of projected electron-density maps at 5.2% RH (relative humidity) and 82.6% RH at resolutions of 133 and 217 nm, respectively, were accomplished.