The instruments of the Large Scale Structures group of the Institut Laue-Langevin are all dedicated to measuring structures on the scale of 1 to several 100 of nanometers. A vast range of science is covered: from magnetism to polymers and colloids to biological structure, in solution, in the solid state or in very thin films.
Information on these large scales is obtained by measuring at especially low Q, i.e. by exploiting neutrons from each of the ILL reactor’s cold sources. Although the instruments all exploit cold neutrons they fall naturally into three classes: small-angle scattering instruments, diffractometers and reflectometers.
Several tens of SANS instruments operates all over the world but ILL's ones offer the highest steady state cold neutron flux.
During a SANS experiment a beam of neutrons is directed at a sample, which can be an aqueous solution, a solid, a powder, or a crystal. The neutrons are elastically scattered by changes of refractive index on a nanometer scale inside the sample which is the interaction with the nuclei of the atoms present in the sample.