Spallation Neutron Source

Last updated
Spallation neutron source logo.png
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 in the U.S. that provides the most intense pulsed neutron 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 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, [2] and it is open to scientists and researchers from all over the world.

Contents

Aerial view of the Spallation Neutron Source building Sns-aerial-800px.jpg
Aerial view of the Spallation Neutron Source building

Neutron scattering research

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.

Spallation process

Three-dimensional rendering of the Spallation Neutron Source facility layout indicating the national laboratory responsible for each primary part of the facility. The areas in red are constructed underground. Sns-facility-design.jpg
Three-dimensional rendering of the Spallation Neutron Source facility layout indicating the national laboratory responsible for each primary part of the facility. The areas in red are constructed underground.

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 which accelerates them to an energy of about one GeV (or to about 90% the speed of light). [3]

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 in a moderator and guided through beam lines to areas containing special instruments where they are used in a wide variety of experiments. [3]

History

Most of the world's neutron 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, and Jefferson. 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. [4]

See also

Related Research Articles

<span class="mw-page-title-main">Oak Ridge National Laboratory</span> Laboratory in Tennessee, United States

Oak Ridge National Laboratory (ORNL) is a federally funded research and development center in Oak Ridge, Tennessee, United States. Founded in 1943, the laboratory is now sponsored by the United States Department of Energy and administered by UT–Battelle, LLC.

<span class="mw-page-title-main">Brookhaven National Laboratory</span> United States Department of Energy national laboratory

Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratory located in Upton, Long Island a hamlet of the Town of Brookhaven. It was formally established in 1947 at the site of Camp Upton, a former U.S. Army base. Located approximately 60 miles east of New York City, it is managed by Stony Brook University and Battelle Memorial Institute.

<span class="mw-page-title-main">SLAC National Accelerator Laboratory</span> Research center at Stanford University

SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center, is a federally funded research and development center in Menlo Park, California, United States. Founded in 1962, the laboratory is now sponsored by the United States Department of Energy and administrated by Stanford University. It is the site of the Stanford Linear Accelerator, a 3.2 kilometer (2-mile) linear accelerator constructed in 1966 that could accelerate electrons to energies of 50 GeV.

<span class="mw-page-title-main">Neutron source</span> Device that emits neutrons

A neutron source is any device that emits neutrons, irrespective of the mechanism used to produce the neutrons. Neutron sources are used in physics, engineering, medicine, nuclear weapons, petroleum exploration, biology, chemistry, and nuclear power. Neutron source variables include the energy of the neutrons emitted by the source, the rate of neutrons emitted by the source, the size of the source, the cost of owning and maintaining the source, and government regulations related to the source.

<span class="mw-page-title-main">Linear particle accelerator</span> Type of particle accelerator

A linear particle accelerator is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear beamline. The principles for such machines were proposed by Gustav Ising in 1924, while the first machine that worked was constructed by Rolf Widerøe in 1928 at the RWTH Aachen University. Linacs have many applications: they generate X-rays and high energy electrons for medicinal purposes in radiation therapy, serve as particle injectors for higher-energy accelerators, and are used directly to achieve the highest kinetic energy for light particles for particle physics.

<span class="mw-page-title-main">Neutron scattering</span> Physical phenomenon

Neutron scattering, the irregular dispersal of free neutrons by matter, can refer to either the naturally occurring physical process itself or to the man-made experimental techniques that use the natural process for investigating materials. The natural/physical phenomenon is of elemental importance in nuclear engineering and the nuclear sciences. Regarding the experimental technique, understanding and manipulating neutron scattering is fundamental to the applications used in crystallography, physics, physical chemistry, biophysics, and materials research.

<span class="mw-page-title-main">Spallation</span> Physical process

Spallation is a process in which fragments of material (spall) are ejected from a body due to impact or stress. In the context of impact mechanics it describes ejection of material from a target during impact by a projectile. In planetary physics, spallation describes meteoritic impacts on a planetary surface and the effects of stellar winds and cosmic rays on planetary atmospheres and surfaces. In the context of mining or geology, spallation can refer to pieces of rock breaking off a rock face due to the internal stresses in the rock; it commonly occurs on mine shaft walls. In the context of anthropology, spallation is a process used to make stone tools such as arrowheads by knapping. In nuclear physics, spallation is the process in which a heavy nucleus emits numerous nucleons as a result of being hit by a high-energy particle, thus greatly reducing its atomic weight. In industrial processes and bioprocessing the loss of tubing material due to the repeated flexing of the tubing within a peristaltic pump is termed spallation.

Plasma acceleration is a technique for accelerating charged particles, such as electrons or ions, using the electric field associated with electron plasma wave or other high-gradient plasma structures. These plasma acceleration structures are created using either ultra-short laser pulses or energetic particle beams that are matched to the plasma parameters. The technique offers a way to build affordable and compact particle accelerators.

<span class="mw-page-title-main">Thomas Jefferson National Accelerator Facility</span> Particle accelerator laboratory in Newport News, Virginia, USA

Thomas Jefferson National Accelerator Facility (TJNAF), commonly called Jefferson Lab or JLab, is a US Department of Energy National Laboratory located in Newport News, Virginia.

<span class="mw-page-title-main">ISIS Neutron and Muon Source</span> English physics research facility

The ISIS Neutron and Muon Source is a pulsed neutron and muon source, established 1984 at the Rutherford Appleton Laboratory of the Science and Technology Facilities Council, on the Harwell Science and Innovation Campus in Oxfordshire, United Kingdom. It uses the techniques of muon spectroscopy and neutron scattering to probe the structure and dynamics of condensed matter on a microscopic scale ranging from the subatomic to the macromolecular.

<span class="mw-page-title-main">European Spallation Source</span> Pulsed neutron source and a research facility

The European Spallation Source ERIC (ESS) is a multi-disciplinary research facility currently under construction, in Lund, Sweden, while its Data Management and Software Centre (DMSC) is situated in Copenhagen, Denmark. The 13 European member countries are partners in the construction and operation of ESS. ESS is scheduled to begin its scientific user program in 2023, with the construction phase set to be completed by 2025. ESS will enable scientists to observe and understand basic atomic structures and forces, which is not achievable with other neutron sources in terms of lengths and time scales. The research facility is located close to the Max IV Laboratory, which conducts synchrotron radiation research. The construction of the facility began in the summer of 2014 and the first science results are planned for 2023.

J-PARC is a high intensity proton accelerator facility. It is a joint project between KEK and JAEA and is located at the Tokai campus of JAEA. J-PARC aims for the frontier in materials and life sciences, and nuclear and particle physics. J-PARC uses high intensity proton beams to create high intensity secondary beams of neutrons, hadrons, and neutrinos.

<span class="mw-page-title-main">Particle accelerator</span> Research apparatus for particle physics

A particle accelerator is a machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams.

<span class="mw-page-title-main">Neutron research facility</span>

A neutron research facility is most commonly a big laboratory operating a large-scale neutron source that provides thermal neutrons to a suite of research instruments. The neutron source usually is a research reactor or a spallation source. In some cases, a smaller facility will provide high energy neutrons using existing neutron generator technologies.

<span class="mw-page-title-main">Los Alamos Neutron Science Center</span> One of the worlds most powerful linear accelerators

The Los Alamos Neutron Science Center (LANSCE), formerly known as the Los Alamos Meson Physics Facility (LAMPF), is one of the world's most powerful linear accelerators. It is located in Los Alamos National Laboratory in New Mexico in Technical Area 53. It was the most powerful linear accelerator in the world when it was opened in June 1972. The technology used in the accelerator was developed under the direction of nuclear physicist Louis Rosen. The facility is capable of accelerating protons up to 800 MeV. Multiple beamlines allow for a variety of experiments to be run at once, and the facility is used for many types of research in materials testing and neutron science. It is also used for medical radioisotope production.

Alvin William Trivelpiece was an American physicist whose varied career included positions as director of the Office of Energy Research of the U.S. Department of Energy (DOE), executive officer of the American Association for the Advancement of Science (AAAS), and director of Oak Ridge National Laboratory (ORNL). He was also a professor of physics and a corporate executive. Trivelpiece's research focused on plasma physics, controlled thermonuclear research, and particle accelerators. He received several patents for accelerators and microwave devices. He died in Rancho Santa Margarita, California in August 2022 at the age of 91.

<span class="mw-page-title-main">China Spallation Neutron Source</span>

The China Spallation Neutron Source is an accelerator-based neutron source, operated by the Institute of High Energy Physics, under construction at Dongguan in Guangdong province - the first major scientific facility in south China. The project was approved by Chinese central government in 2005. Construction began 20 October 2011, with commissioning planned for 2016, and operation in 2018.

<span class="mw-page-title-main">John M. Carpenter</span> American nuclear engineer (1935–2020)

John M. "Jack" Carpenter was an American nuclear engineer known as the originator of the technique for utilizing accelerator-induced intense pulses of neutrons for research and developing the first spallation slow neutron source based on a proton synchrotron, the Intense Pulsed Neutron Source (IPNS). He died on 10 March 2020.

An electron–ion collider (EIC) is a type of particle accelerator collider designed to collide spin-polarized beams of electrons and ions, in order to study the properties of nuclear matter in detail via deep inelastic scattering. In 2012, a whitepaper was published, proposing the developing and building of an EIC accelerator, and in 2015, the Department of Energy Nuclear Science Advisory Committee (NSAC) named the construction of an electron–ion collider one of the top priorities for the near future in nuclear physics in the United States.

The National User Facilities are a set of large-scale scientific facilities maintained by the U.S. Department of Energy, Office of Science, whose roles are to provide the scientific community with world-leading scientific instruments to enable research. These facilities are generally free to use, and are open to scientists from all over the world, usually through the submission and evaluation of research proposals.

References

  1. In 2007, SNS was entered into the Guinness Book of World Records as the most powerful pulsed spallation source.
  2. User Facilities | U.S. DOE Office of Science (SC)
  3. 1 2 "How SNS Works | Neutron Science at ORNL". neutrons.ornl.gov. Retrieved 2018-06-15.
  4. "Spallation Neutron Source | Neutron Science at ORNL".

35°57′04″N84°18′07″W / 35.951°N 84.302°W / 35.951; -84.302