Quantitative research on higher order harmonics in metrology beamline

查看全文 作　　者：Hongjun [1]ZHOU;Jinjin [2]ZHENG;Tonglin [1]HUO;Guobin [1]ZHANG;Zeming [1]QI;Pengfei [2]ZHONG 机构地区：[1]National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China;[2]Department of Precision Machinery and Precision Instrumentation,University of Science and Technology of China,Hefei 230026,China 出　　处：《Frontiers of Electrical and Electronic Engineering in China》索引2008年第3卷第1期,共5页 基　　金：This work was supported by the National Natural Science Foundation of China(No.10575097 and 60473133);the 100 Talents Programme of the Chinese Academy of Sciences;the National Basic Research Program of China(No.2006CB303102);Specialized Research Fund for the Doctoral Program of Higher Education(No.20060358050). 摘　　要：The synchrotron radiation spectra of the spherical grating monochromator(SGM)working in the soft X-ray and VUV region are often contaminated by significant amounts of higher order harmonics.They cannot be suppressed completely by suitable filters.Higher order contributions in the spectral radiation standard and metrology beamline were researched using transmission grating(made in-house)and IRD AXUV100G(USA)photodiode detector.The exit beam was dispersed with the transmission grating behind the exit slit of the monochromator,and the contributions of the different orders were analyzed.The higher order distributions were quantitatively determined for three gratings with line densities of 1800,600 and 200 l/mm.Experiment results show that in wavelengths between 5 nm and 15 nm the contributions of the higher orders to the detector signal are restricted to less than 7%even without the use of filters.In wavelength regions between 5 nm and 34 nm,the contributions of the higher orders to the detector signal are less than 14%with proper Al,Si_(3)N_(4) and Zr filters,and after being modified by quantum efficiency of the detector,the higher order contributions are restricted to less than 6.5%.The study also shows that higher orders are almost totally suppressed by MgF_(2) filter when the wavelength ranges between 115–140 nm. 关 键 词：spectral radiation standard higher order harmonics spectral radiation metrology