Neutron Production, Scattering and its Applications to Soft Materials

Neutrons in sufficient quantities (e.g., > 10¹⁴ n/(cm² s)) are produced either by nuclear fission using a reactor, or through spallation in which protons that have been accelerated to high velocities collide with a heavy metal target (e.g., mercury, tantalum), causing the material to expel 20-30 neutrons per impact. Oak Ridge National Laboratory has access to both type of neutron sources, namely the reactor-based High Flux Isotope Reactor (HFIR) and the accelerator-based Spallation Neutron Source (SNS). In this lecture I will begin with the discovery of the neutron in 1932 by James Chadwick, describe the development of neutron scattering in Canada and the United States, and conclude with the application of neutron scattering techniques to current soft materials problems, particularly those concerning the biological systems.