超环面镜对同步辐射硬X光束空间相干性的影响  

Effect of toroidal mirror on spatial coherence of synchrotron hard X-ray beams

作　　者：王华[1] 闫帅[1] 闫芬[1] 毛成文[1] 梁东旭[1] 何燕[1] 蒋升[1] 李爱国[1] 余笑寒[1] 

机构地区：[1]中国科学院上海应用物理研究所,上海201204

出　　处：《核技术》2012年第8期583-586,共4页Nuclear Techniques

基　　金：国家自然科学基金(11075200;11104307);国家重大基础研究发展计划(2010CB934501)资助项目

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(BL15U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。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.

关 键 词：同步辐射 空间相干性 等效光源假设 超环面镜 高斯-谢尔光源模型 

分 类 号：O434[机械工程—光学工程]