Neutron scattering

Thermal neutron scattering is a very important probe of the properties of condensed matter. This paper discusses the reactor sources of such neutrons for scattering and the major instruments at these sources. Neutron diffraction leads to studies on the structure of powders, magnetic materials, liquids and amorphous solids, and the shapes of polymers, micelles, colloids and biological molecules. Neutron inelastic scattering studies spin waves, excitations in incommensurate structures, diffusion processes and critical scattering. Future possibilities are even more extensive than past accomplishments. (orig.)