Spallation Neutron Source
 |
|
| A DOE Office of Science User Facility | |
|---|---|
| Location: | Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States |
| Scientific Purpose: | Provide unique information about the structure and properties of materials across the spectrum of biology, chemistry, physics, and engineering. |
| Organization: | SNS is part of the ORNL Neutron Sciences Directorate, which also includes the High Flux Isotope Reactor, a steady-state neutron source. |
| Web site: | neutrons.ornl.gov |
The Spallation Neutron Source (SNS) is an accelerator-based neutron source facility that provides the most intense pulsed neutron beams in the world for scientific research and industrial development. Each year, this facility hosts hundreds of researchers from universities, national laboratories, and industry, who conduct basic and applied research and technology development using neutrons. SNS is part of Oak Ridge National Laboratory, which is managed by UT-Battelle for the United States Department of Energy (DOE). SNS is a DOE Office of Science user facility, and it is open to scientists and researchers from all over the world.
Neutron scattering allows scientists to count scattered neutrons, measure their energies and the angles at which they scatter, and map their final positions. This information can reveal the molecular and magnetic structure and behavior of materials, such as high-temperature superconductors, polymers, metals, and biological samples. In addition to studies focused on fundamental physics, neutron scattering research has applications in structural biology and biotechnology, magnetism and superconductivity, chemical and engineering materials, nanotechnology, complex fluids, and others.
The spallation process at SNS begins with negatively charged hydrogen ions that are produced by an ion source. Each ion consists of a proton orbited by two electrons. The ions are injected into a linear particle accelerator, or linac, which accelerates them to very high energies (eventually to 90% the speed of light). The ions pass through a foil, which strips off each ion's two electrons, converting it to a proton. The protons pass into a ring-shaped structure, a proton accumulator ring, where they spin around at very high speeds and accumulate in “bunches.” Each bunch of protons is released from the ring as a pulse, at a rate of 60 times per second (60 hertz). The high-energy proton pulses strike a target of liquid mercury, where spallation occurs. The spalled neutrons are then slowed down in a moderator and guided through beam lines to areas containing special instruments where they are used in a wide variety of experiments.
...
Wikipedia