Meng Xiangyu, Xue Chaofan, Yu Huaina, Wang Yong, Wu Yanqing, Tai Renzhong
Opt Express. 2015 Nov 16;23(23):29675-86. doi: 10.1364/OE.23.029675.
A new model for numerical analysis of partially coherent x-ray at synchrotron beamlines is presented. The model is based on statistical optics. Four-dimensional coherence function, Mutual Optical Intensity (MOI), is applied to describe the wavefront of the partially coherent light. The propagation of MOI through optical elements in the beamline is deduced with numerical calculation. The coherence of x-ray through beamlines can be acquired. We applied the model to analyze the coherence in the STXM beamline at SSRF, and got the coherence length of the beam at the endstation. To verify the theoretical results, the diffraction experiment of a single slit was performed and the diffraction pattern was simulated to get the coherence length, (31 ± 3.0) µm × (25 ± 2.1) µm (H × V), which had a good agreement with the theoretical results, (30.7 ± 0.6) µm × (31 ± 5.3) µm (H × V). The model is applicable to analyze the coherence in synchrotron beamlines.
提出了一种用于同步辐射光束线部分相干X射线数值分析的新模型。该模型基于统计光学。应用四维相干函数——互光强（MOI）来描述部分相干光的波前。通过数值计算推导了MOI在光束线光学元件中的传播。可以获得X射线通过光束线的相干性。我们应用该模型分析了上海光源STXM光束线的相干性，并得到了终端站处光束的相干长度。为了验证理论结果，进行了单缝衍射实验，并对衍射图样进行了模拟以获得相干长度，（31±3.0）μm×（25±2.1）μm（水平×垂直），与理论结果（30.7±0.6）μm×（31±5.3）μm（水平×垂直）吻合良好。该模型适用于分析同步辐射光束线中的相干性。
