Spin-echo resolved grazing incidence scattering (ESRGIS) of cold neutrons

The conceptual design of a new instrument is presented, which makes use of the spin echo technique to analyze the scattering angle of neutrons impinging upon a rough or corrugated surface at grazing incidence. In a grazing incidence geometry the roughness of the surface and of submersed interfaces give rise to a neutron scattering pattern at angles well resolved from that of specular reflection for corrugation lengths up to several microns, but only in the plane of specular reflection. In contrast, scattering caused by corrugations of comparable length perpendicular to the reflection plane is limited to angles that can be separated only with an extreme tightening of the instrumental resolution. However this scattering can be well resolved by spin-echo methods for polarized neutrons. Results from scattering in and out of the reflection plane provide complementary information on the structure of the roughness and its location in a system with complex layering. This spin-echo technique may also distinguish static from time-dependent roughness