Development of EUV multilayer mirrors for astronomical observation in IPOE

Three kinds of multilayer mirrors were developed for solar observation and earth's magnetosphere observation at Extreme Ultraviolet (EUV) wavelength region. The first one is Mo/Si multilayer mirror, designed for solar Fe-XII emission line at wavelength of 19.5nm. The reflectivities are in the range of 38.7~42.9%, measured at National Synchrotron Radiation Laboratory (NSRL), Hefei, China. The second high-reflective multilayer is designed for solar He-II radiation at 30.4 nm. At this wavelength, SiC/Mg multilayers were investigated, and as high as 50.0% measured reflectivity was obtained at incident angle of 10°. Aperiodic SiC/Mg multilayers were also designed for wide angular ranges of 15-22° and 12-21°. The third multilayer mirror was a dual-function mirror used for earth's magnetosphere observation, which requires high-reflective for He-II emission line at wavelength of 30.4nm but low-reflectance at 58.4nm from ionosphere He-I emission. Using aperiodic SiC/Mg multilayer stack, the dual-function multilayer mirror was designed by genetic algorithm. Compared to periodic multilayer, the dual-function multilayer suppresses the reflectivity for He-I at 58.4nm from 2.2% to 0.1%, without loss of the reflection for He-II at 30.4nm, significantly. These multilayer mirrors were all prepared by magnetron sputtering system in IPOE, and measured at NSRL, China.

[1]  Benjawan Kjornrattanawanich,et al.  EUV multilayers for solar physics , 2004, SPIE Optics + Photonics.

[2]  Eric M. Gullikson,et al.  Soft-X-ray reflectivity and heat resistance of SiC/Mg multilayer , 2005 .

[3]  Piergiorgio Nicolosi,et al.  Development of multilayer coatings for solar space experiments , 2003, SPIE Astronomical Telescopes + Instrumentation.

[4]  D. Garoli,et al.  Space applications of Si/B4C multilayer coatings at extreme ultra-violet region; comparison with standard Mo/Si coatings , 2005, SPIE Optics + Photonics.

[5]  Katsuhiko Saito,et al.  Aging and thermal stability of Mg/SiC and Mg/Y2O3 reflection multilayers in the 25-35 nm region. , 2005, Applied optics.

[6]  E. Spiller,et al.  Reflective multilayer coatings for the far uv region. , 1976, Applied optics.

[7]  Igor A. Zhitnik,et al.  Instruments for imaging XUV spectroscopy of the sun on board the CORONAS-I satellite , 1998, Other Conferences.

[8]  David D. Allred,et al.  Dual-function EUV multilayer mirrors for the IMAGE mission , 1999 .

[9]  Soizik Donguy,et al.  Experimental comparison of extreme-ultraviolet multilayers for solar physics. , 2004, Applied optics.

[10]  Xu,et al.  Research of multilayers in EUV, soft X-ray and X-ray , 2005 .

[11]  Ni Qi.  Development of a space soft X-ray and EUV normal incidence telescope , 2003 .

[12]  M. Lampton,et al.  An EUV spectrometer for mapping the heliopause and solar wind , 2005, SPIE Optics + Photonics.

[13]  Steven E. Benzley,et al.  The Use of Genetic Algorithms in Multilayer Mirror Optimization , 2004 .