Grazing incidence neutron diffraction from large scale 2D structures

The distorted wave Born approximation (DWBA) is applied to evaluate the dif fraction pattern of neutrons (or X-rays) from a 2D array of dots deposited onto a dissimilar substrate. With the radiation impinging on the surface at a grazing incidence angle alpha, the intensities diffracted both in and ou t the plane of specular reflection are calculated as a function of the peri odicity of the array, height and diameter of the dots. The results are pres ented in the form of diffracted intensity contours in a plane with coordina tes alpha and alpha', the latter being the glancing angle of scattering. Th e optimization of the experimental conditions for polarized neutron experim ents on submicron dots is discussed. The feasibility of such measurements i s confirmed by a test experiment. (C) 2000 Elsevier Science B.V. All rights reserved.