软X射线光发射电子显微镜光束线聚焦用KB镜系统

摘要

A high accuracy micro-focusing system was designed to improve the light spot focusing quality of the X-ray beam-line for Photo-emission Electron Microscope ( PEEM ) in Shanghai Synchrotron Radiation Facility (SSRF) .The layout of PEEM beam-line of the SSRF was introduced and basic parameters of optics of the micro-focusing system were presented .Two Kirkpatrick-Baez mirrors (KB mirror) were adopted to finish the design of micro-focusing system .The design scheme of a key component-posture adjusting mechanism in the system was introduced . Namely , a three vertical linear driving equipment and a two horizontal linear driving device were combined to implement five-dimensional adjustment of the system . The working principle and process of the posture adjusting mechanism were introduced ,and the overall design scheme of micro-focusing system were analyzed deeply .The mechanical performance of KB mirror system was tested ,and the testing results of the horizontal adjusting mechanism and the pitch motion of first mirror were given .That the resolution and repeat accuracy of horizontal adjusting mechanism are 0 .6 μm and 0 .85 μm respectively ,and those of pitch motion are 0 .4″and 0 .5″respectively ,w hich are better than that of the technical requirements .The other parameters were tested as well ,and the results also satisfy the technical requirements .The realization of technical targets of KB mirror system guarantees the high quality focusing of PEEM bean-line .%研制了光发射电子显微镜(PEEM)高精度微聚焦系统,以实现上海光源软X射线PEEM光束线的高质量聚焦.根据上海光源PEEM光束线的概况,给出微聚焦系统光学元件的基本参数.基于Kirkpatrick-Baez(KB镜)两镜方案,设计了PEEM线微聚焦系统.介绍了KB镜姿态调整机构的设计方案,即利用三垂直线性驱动装置和两水平线性驱动装置相结合来实现五维调节,分析了姿态调节机构的原理与工作过程,给出了微聚焦系统的整体设计方案.测试了KB镜系统的机械性能,给出水平调节机构以及第一面镜子Pitch运动的测试结果,结果显示:水平调节机构分辨率为0.6μm,重复精度为0.85μm,Pitch角度分辨率为0.4″,重复精度为0.5″,优于指标要求.其它参数的测试结果亦均优于指标要求.实验表明,微聚焦系统机械指标的实现保证了PEEM线光斑的高质量聚焦.