Dynamical effects in Bragg coherent x-ray diffraction imaging of finite crystals
Dynamical effects in Bragg coherent x-ray diffraction imaging of finite crystals
复制标题
有限晶体布拉格相干 X 射线衍射成像的动力学效应
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
I. Vartanyants
中科院分区：
文献类型：
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作者：
A. Shabalin;O. Yefanov;V. Nosik;V. Bushuev;I. Vartanyants
在X射线衍射动力学理论的框架下，对有限晶体的布拉格相干X射线衍射成像(CXDI)数据进行了模拟。该方法基于修正的Takagi-Taupin方程的数值解，可用于有限个任意形状的三维晶体在应变作用下的大范围X射线衍射实验的模拟。我们对不同尺寸的立方形和半球形纳米晶体进行了模拟，并对动态衍射引入的Bragg CXDI重建中的伪影进行了详细分析。描述了一种由解析导数支持的处理折射和吸收效应的简便方法。我们的结果阐明了Bragg CXDI中运动学方法的局限性，并提出了一个在有限晶体上相干X射线衍射中区分运动学和动力学情况的自然标准。
We present simulations of Bragg Coherent X-ray Diffractive Imaging (CXDI) data from finite crystals in the frame of the dynamical theory of x-ray diffraction. The developed approach is based on numerical solution of modified Takagi-Taupin equations and can be applied for modeling of a broad range of x-ray diffraction experiments with finite three-dimensional crystals of arbitrary shape also in the presence of strain. We performed simulations for nanocrystals of a cubic and hemispherical shape of different sizes and provided a detailed analysis of artifacts in the Bragg CXDI reconstructions introduced by the dynamical diffraction. A convenient way to treat effects of refraction and absorption supported by analytical derivations is described. Our results elucidate limitations for the kinematical approach in the Bragg CXDI and suggest a natural criterion to distinguish between kinematical and dynamical cases in coherent x-ray diffraction on a finite crystal.