Molybdenum/Silicon multilayer mirrors for 4.47nm x-ray

It is well-known that Molybdenum/Silicon multilayer films have achieved very high reflectivity at the wavelengths between 13.0-13.5nm. Reported here is a new phenomenon where Mo/Si multilayer also have a high reflectivity, 8.5% with 60° incidence angle, at λ=4.47nm. To our knowledge, this is the first result obtained at this wavelength from Mo/Si multilayers.