软X射线双频光栅剪切干涉法研究  

Studies on soft X-ray shearing interferometry with double-frequency gratings

作　　者：刘正坤[1] 邱克强[1] 陈火耀[1] 刘颖[1] 徐向东[1] 付绍军[1] 王琛[2] 安红海[2] 方智恒[2] 

机构地区：[1]中国科学技术大学国家同步辐射实验室,合肥230029 [2]上海激光等离子体研究所,上海201800

出　　处：《物理学报》2013年第7期115-120,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10975135;11075146)资助的课题~~

摘　　要：本文中设计了一种利用软X射线双频光栅作为剪切干涉元件的剪切系统,使剪切干涉法在软X射线波段得到了应用.介绍了软X射线双频光栅的结构及衍射特性,在同步辐射光束线对双频光栅的效率分布进行了测试实验,两个剪切级次的效率比值高于75%,干扰级次效率低于5%.利用软X射线双频光栅为剪切干涉光学元件,对待测靶进行了静态检测,得到了对比度高,稳定的干涉条纹,验证了该方法在软X射线等离子体密度诊断中的可行性.The M-Z interferometer with gratings or multilayer mirrors is widely used in the X-ray laser plasma diagnoses; however, this system is difficult to adjust, and results in the low success rate in experiment. Since wavefront shearing interferometers do not need a separate reference wavefront, they have inherent advantages compared with conventional interferometers. But the absence of shearing element for soft X-ray has restrained the application of the shearing interferometry in soft X-ray measurement. In this paper, a new-structured double-frequency grating was proposed and fabricated that served as the shearing element for soft X-rays, which can promote the application of shearing interferometers in the X-ray laser plasma diagnoses. The diffraction characteristics of the double-frequency grating are analyzed and tested in the synchrotron radiation beams. It is found that the intensity ratio of the two working diffracted beams is over 75%, and the intensity ratio of the rest diffracted beam to the working beam is less than 5%. An X-ray shearing interferometer using a double-frequency grating with 1000 lines/mm and 1002.5 lines/mm gratings was set up, and a clear shear interferogram was obtained. The experimental results demonstrated that the soft X-ray shearing interferometer using double-frequency grating can be applied in the X-ray laser plasma diagnoses.

关 键 词：双频光栅 剪切干涉仪 软X射线 等离子体诊断 

分 类 号：O436.1[机械工程—光学工程]