A spallation neutron source (SNS) is a type of particle accelerator that produces high-energy neutrons by bombarding a heavy metal target with protons. The proton beam interacts with the nuclei of the target atoms, causing them to break up or “spall” into lighter elements and products. The neutrons produced can then be used for a variety of scientific and technological applications.
SNSs are typically large and expensive facilities, but they offer several advantages over other types of neutron sources. First, the high energy of the neutrons produced (usually in the range of 10-100 MeV) makes them ideal for studies of materials at the atomic level. Second, the SNS can be tuned to produce a wide range of neutron energies, making it suitable for a variety of experiments. Finally, the SNS is a very intense source of neutrons, producing up to 1015 neutrons per second. This high intensity makes it possible to conduct experiments that would otherwise be impractical or impossible.
The first SNS was built at Los Alamos National Laboratory in 1983. Since then, several more have been constructed around the world, including facilities in France, Japan, Russia, and Sweden. In addition, there are several proposed projects for new or upgraded SNSs in China, India, South Korea, and elsewhere.