Optical theorem for neutron scattering from rough interfaces

The optical theorem (OT) is formulated as the result of the interference be tween the waves scattered from surface roughness and the waves reflected fr om, or transmitted through the film. It is argued that the OT explicitly in corporated into the reflectivity data treatment may provide a set of the ba sic parameters: root-mean-square (rms) surface roughness sigma, height-heig ht correlation length xi, and the fractional decay rate exponent h. (C) 200 0 Elsevier Science B.V. All rights reserved.