Helium backscattering from a randomly stepped surface

Inelastic multiphonon helium scattering from a stepped Ni„977... surface

The multiphonon energy exchange between a neutral He atom and a stepped Ni~977! surface has been measured in order to examine how the presence of a regular array of atomic-scale steps on a surface modifies energy exchange in the classical multiphonon scattering regime. At elevated substrate temperatures, we compare the multiphonon scattering with the predictions of a classical theory that has p...

Backscattering measurements from double-scale randomly rough surfaces.

We present experimental measurements of light backscattered from double-scale randomly rough surfaces (oceanlike surfaces) with different statistical parameters illuminated at small and large angles of incidence. The surfaces are composed of a small-scale roughness superimposed on a slowly (large-scale) varying surface. The large-scale surfaces are diamond-machined periodic surfaces made on alu...

Neutron reflection from the liquid helium surface

Detection and Imaging in Strongly Backscattering Randomly Layered Media

Echoes from small reflectors buried in heavy clutter are weak and difficult to distinguish from the medium backscatter. Detection and imaging with sensor arrays in such media requires filtering out the unwanted backscatter and enhancing the echoes from the reflectors that we wish to locate. We consider a filtering and detection approach based on the singular value decomposition of the local cos...

Surfactant-Coated Nanoparticle on a Stepped Surface

Metal and semiconductor particles of nanometer (nm) size feature a large surface-tovolume ratio and quantum-scale dimensions. Due to the distinct energetics of surfaces atoms and the unique energy-level structures, these nanoparticles possess extraordinary thermodynamic, chemical, electric, optical, and magnetic properties unlike those of isolated atoms and bulk systems. Equally importantly, th...