中文摘要：

首先建立上海同步辐射装置波荡器光源（硬X射线微聚焦光束线站）的面光源高斯．谢尔模型（GSM），其次由高斯．谢尔光源模型与广义惠更斯．菲涅耳原理，推导出部分相干光束交叉谱密度函数在自由空间的传输规律，进而讨论了同步辐射光束空间相干性在自由空间的传输规律。最后，提出了等效光源假设理论，并用该理论研究了上海光源硬X射线微聚焦光束线站（BLl5U光束线站）超环面镜对同步辐射光束空间相干性的影响。将该理论计算结果与实验结果进行了比较，结果表明理论与实验符合较好，证明等效光源假设理论有效。由于等效光源假设理论只涉及到入射光束与出射光束的发散角，所以可扩展到其他束线光学元件。

英文摘要：

The Gaussian Schell-model source theory is used to describe the hard X-ray micro focusing beamline with an undulator of the Shanghai Synchrotron Radiation Facility. Based on the model and general Huygens-Fresnel principle, propagation of cross-spectral density function in free space is studied. Equivalent source hypothesis is proposed and the effect of toroidal mirror on spatial coherence of the hard X-ray beams is studied. The theoretical results are consistent with the experimental results. Only divergence angles of the incident and outgoing X-rays are considered in the equivalent source hypothesis, hence an easy extension of the hypothesis to other beamline optical elements.