Reflectivity and Roughness of X-ray Multilayer Mirrors. Specular Reflection and Angular Spectrum of Scattered Radiation

Abstract

A simple and accurate analytical model for the reflectivity of an X-ray multilayer mirror has been developed. This model can be used in the determination of interfacial roughness over large ranges of wavelength and roughness. There are no restrictions such as the roughness being less than the scale of the wavelength such as are present in theories based on the multiplication of the sharp boundary reflectivity coefficient by an exponential factor. The model is also applied to scattered radiation. Angular spectra are calculated and the use of scattered radiation in determining interfacial roughness is demonstrated.