Spallation Neutron Source

<h2 id="neutron-scattering-research">Neutron scattering research</h2>
<p><a href="/facts/Neutron_scattering/wMze4rvs">Neutron scattering</a> 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 <a href="/facts/Magnetic_structure/SPQjl7BM">magnetic structure</a> and behavior of materials, such as high-temperature <a href="/facts/Superconductivity/pqQAlSzJ">superconductors</a>, <a href="/facts/Polymers/eF32E50K">polymers</a>, metals, and biological samples. In addition to studies focused on fundamental physics, neutron scattering research has applications in <a href="/facts/Structural_biology/XRkPtHYv">structural biology</a> and <a href="/facts/Biotechnology/8eFnI6FB">biotechnology</a>, magnetism and superconductivity, chemical and engineering materials, <a href="/facts/Nanotechnology/Co4FFNfY">nanotechnology</a>, <a href="/facts/Complex_fluids/lpW7ABuy">complex fluids</a>, and others.
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<h2 id="spallation-process">Spallation process</h2>

<p>The <a href="/facts/Spallation/k7AsUBbk">spallation</a> process at SNS begins with negatively charged <a href="/facts/Hydrogen/BoYHjl0J">hydrogen</a> ions that are produced by an <a href="/facts/Ion_source/3hP3h1sM">ion source</a>. Each ion consists of a <a href="/facts/Proton/clCjepXP">proton</a> orbited by two <a href="/facts/Electrons/L0KBo5cW">electrons</a>. The ions are injected into a <a href="/facts/Linear_particle_accelerator/GIz6Uc4x">linear particle accelerator</a> which accelerates them to an energy of about one <a href="/facts/Electronvolt/YMT1fqX9">GeV</a> (or to about 90% the <a href="/facts/Speed_of_light/sKSQwdNx">speed of light</a>).<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> 
</p><p>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 <a href="/facts/Accumulator_(energy)/qnvvAVvb">accumulator ring</a>, 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 <a href="/facts/Hertz/6Wshj5qm">hertz</a>). The high-energy proton pulses strike a target of liquid <a href="/facts/Mercury_(element)/WlxfoHva">mercury</a>, where <a href="/facts/Spallation/k7AsUBbk">spallation</a> occurs. The spalled neutrons are then slowed in a <a href="/facts/Neutron_moderator/1qa6YvDD">moderator</a> and guided through beam lines to areas containing special instruments where they are used in a wide variety of experiments.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
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<h2 id="history">History</h2>
<p>Most of the world's <a href="/facts/Neutron_source/4BTQAu9l">neutron sources</a> 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.
</p><p>The construction of SNS was a partnership of six DOE national laboratories: <a href="/facts/Argonne_National_Laboratory/EAoR1Rnm">Argonne</a>, <a href="/facts/Brookhaven_National_Laboratory/L2JrG0K1">Brookhaven</a>, <a href="/facts/LBNL/tvjPSwC9">Lawrence Berkeley</a>, <a href="/facts/LANL/tlrLkV7r">Los Alamos</a>, <a href="/facts/Oak_Ridge_National_Laboratory/Elq84HKF">Oak Ridge</a>, and <a href="/facts/Jefferson_Lab/E9htoumr">Jefferson</a>. 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.
</p><p>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.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a>
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<h2 id="see-also">See also</h2>

<ul><li><a href="/facts/Materials_science/N5HrXRYW">Materials science</a></li>
<li><a href="/facts/Neutron_detection/8BRncp82">Neutron detection</a></li>
<li><a href="/facts/Neutron_electric_dipole_moment/KF1GVz7Q">Neutron electric dipole moment</a></li>
<li><a href="/facts/Neutron_facilities/wXjGL6PF">Neutron facilities</a></li>
<li><a href="/facts/Neutron_scattering/wMze4rvs">Neutron scattering</a></li>
<li><a href="/facts/NPDGamma_experiment/woR4aTDx">NPDGamma experiment</a></li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="http://neutrons.ornl.gov">Official website</a> </li>
<li>T. E. Mason et al., "The Spallation Neutron Source: A Powerful Tool for Materials Research," <a href="https://arxiv.org/abs/physics/0007068">arXiv:physics/0007068v1.</a></li>
<li><a href="https://www.symmetrymagazine.org/article/junejuly-2006/sns-neutrons-for-molecular-movies">"SNS: Neutrons for 'molecular movies,'" <i>Symmetry,</i> vol. 03(05), Jun/Jul, 2006.</a></li></ul>
<p><a href="https://geohack.toolforge.org/geohack.php?pagename=Spallation_Neutron_Source¶ms=35.951_N_84.302_W_type:landmark_region:US">35°57′04″N 84°18′07″W / 35.951°N 84.302°W / 35.951; -84.302</a>
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<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>In 2007, SNS was entered into the Guinness Book of World Records as the most powerful pulsed spallation source. <a href="http://www.guinnessworldrecords.com/records-5000/most-powerful-pulsed-spallation-neutron-source/" target="_blank">http://www.guinnessworldrecords.com/records-5000/most-powerful-pulsed-spallation-neutron-source/</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>User Facilities | U.S. DOE Office of Science (SC) <a href="http://science.energy.gov/user-facilities/" target="_blank">http://science.energy.gov/user-facilities/</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>"How SNS Works | Neutron Science at ORNL". neutrons.ornl.gov. Retrieved 2018-06-15. <a href="http://neutrons.ornl.gov/content/how-sns-works" target="_blank">http://neutrons.ornl.gov/content/how-sns-works</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>"How SNS Works | Neutron Science at ORNL". neutrons.ornl.gov. Retrieved 2018-06-15. <a href="http://neutrons.ornl.gov/content/how-sns-works" target="_blank">http://neutrons.ornl.gov/content/how-sns-works</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>"Spallation Neutron Source | Neutron Science at ORNL". <a href="https://neutrons.ornl.gov/sns" target="_blank">https://neutrons.ornl.gov/sns</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
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Spallation Neutron Source open-in-new

Spallation Neutron Source