Diffraction by a surface with random terrace distribution: an analytical calculation

We propose a new scheme in order to calculate analytically the diffracted intensity by a surface with random terrace distribution. We apply it to a two-level system and show that the average diffracted intensity depends simply on the characteristic function of the terrace's length distribution. We use this analytical result to connect the various details of the diffraction pattern - characteristics of the diffraction satellites and properties of the zone centre region - to the main features of the terrace distribution. (C) 1997 Elsevier Science B.V.