前置平面镜热负载对变包含角平面光栅单色器分辨率的影响  

Effects of plane mirror thermal load on variable included angle plane-grating monochromator resolution

作　　者：宋源[1,2] 卢启鹏[1] 彭忠琦[1] 龚学鹏[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《中国光学》2014年第1期105-111,共7页Chinese Optics

基　　金：国家自然科学基金资助项目(No.11079035);国家科技重大专项资助项目(No.2012ZX02702001);应用光学国家重点实验室开放基金资助项目(No.Y2Q03FQK02)

摘　　要：针对变包含角平面光栅单色器前置平面镜(PM)受热负载而导致的单色器分辨率降低问题,提出优化聚焦常数(C ff)补偿分辨率的方法。首先,计算不同C ff值时PM的热功率吸收谱,在此基础上对镜面热负载进行热-结构耦合分析,得到不同热负载时PM表面热变形的变化量;然后,结合理想分辨率公式和光线追迹软件求出加热负载的单色器分辨率;最后,优化C ff实现分辨率的补偿。研究结果表明,以软X射线谱学显微光束线站为例,当出射光能量为1 000 eV时,将C ff由1.8优化至1.84,单色器分辨率即可与无热负载时的相同,该优化方法可有效补偿单色器分辨率的降低。In synchrotron radiation beamlines , the increasing light flux will lead to more thermal load on opti-cal elements .The thermal load on the Plane Mirror （ PM） of variable included angle plane-grating monochrom-ator will decrease the resolution .This paper proposes a method to recover the resolution by optimizing the val-ue of focusing constant（Cf ）.Firstly, the absorption spectra of thermal power with different values of Cf are obtained by calculation .Then thermo-mechanical analysis of PM is conducted to get variable deformations on PM with different thermal power .Secondly , the resolution is calculated by combining the function of ideal res-olution and the software of ray tracing .Finally, the resolution is compensated by optimizing Cf .The result in-dicates that taking the soft X-ray spectroscopy micro beam line station of SSRF for example , the resolution can be improved by changing the value of Cf from 1.8 to 1.84 when the photon energy is 1 000 eV.So optimizing＆amp;nbsp;the value of Cf is an effective way to recover the decreased resolution induced by thermal power on PM .

关 键 词：变包含角平面光栅单色器 热负载 聚焦常数 分辨率 斜率误差 

分 类 号：TH744.1[机械工程—光学工程] TB24[机械工程—仪器科学与技术]