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| A DOE Office of Science User Facility | |
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| 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 |
| Science withneutrons |
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| Foundations |
| Neutron scattering |
| Other applications |
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| Infrastructure |
| Neutron facilities |
TheSpallation Neutron Source (SNS) is an accelerator-basedneutron source facility in the U.S. that provides the most intense pulsedneutron beams in the world for scientific research and industrial development.[1] Each year, the 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 ofOak Ridge National Laboratory, which is managed byUT-Battelle for theUnited States Department of Energy (DOE). SNS is a DOE Office of Science user facility,[2] and it is open to scientists and researchers from all over the world.
Most of the world'sneutron sources were built decades ago, and although the uses and demand for neutrons have increased throughout the years, few new sources have been built. To fill that need for a new, improved neutron source, the DOE Office of Basic Energy Sciences funded the construction of SNS, which would provide the most intense pulsed neutron beams in the world for scientific research and industrial development.
The construction of SNS was a partnership of six DOE national laboratories:Argonne,Brookhaven,Lawrence Berkeley,Los Alamos,Oak Ridge, andJefferson. This collaboration was one of the largest of its kind in U.S. scientific history and was used to bring together the best minds and experience from many different fields.
After more than five years of construction and a cost of $1.4 billion, SNS was completed in April 2006. The first three instruments began commissioning and were available to the scientific community in August 2007. As of 2017, 20 instruments have been completed, and SNS is hosting about 1,400 researchers per year.[3]
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 andmagnetic structure and behavior of materials, such as high-temperaturesuperconductors,polymers, metals, and biological samples. In addition to studies focused on fundamental physics, neutron scattering research has applications instructural biology andbiotechnology, magnetism and superconductivity, chemical and engineering materials,nanotechnology,complex fluids, and others.
Thespallation process at SNS begins with negatively chargedhydrogen ions that are produced by anion source. Each ion consists of aproton orbited by twoelectrons. The ions are injected into alinear particle accelerator which accelerates them to an energy of about oneGeV (or to about 90% thespeed of light).[4]
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 protonaccumulator 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 (60hertz). The high-energy proton pulses strike a target of liquidmercury, wherespallation occurs. The spalled neutrons are then slowed in amoderator and guided through beam lines to areas containing special instruments where they are used in a wide variety of experiments.[4]
35°57′04″N84°18′07″W / 35.951°N 84.302°W /35.951; -84.302
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| Under Secretary of Energy for Infrastructure | Office of Cybersecurity, Energy Security, & Energy Response | |
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