Numerical simulation of gliding reflection of X-ray beam from rough   surface
  A new method for investigation of x-ray propagation in a rough narrow dielectric waveguide is proposed on the basis of the numerical integration of the quazioptical equation. In calculations a model rough surface was used with the given statistical properties. It was shown that the losses in the narrow waveguides strongly depend on the wall roughness and on the input angle. The losses are not zero even at zero input angle if the width of the waveguide is smaller or about 1 mkm. The effect is accounted for as the influence of diffraction. The angular spread of the transmitted X-ray radiation is much more narrow than the Fresnel angle of the total external reflection. 
T.A.Bobrova, L.I.Ognev (Kurchatov Institute, Moscow)