Reflectivity of W/Si Multilayer at the Photoenergy of 700eVand 1200eV

We have deposited W/Si multilayer mirrors using magnetron
sputtering, and measured their reflectivity at the Beijing synchrotron Radiation Facility. The W/Si multilayer mirrors show the peak reflectivity of approximately 10% at a photo-energy of 1200eV and 10.5% at a photo-energy of 700eV at the incidence angle of 81°. So far, no higher reflectivity than that given in this letter has been reported.