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Some isotopes undergo spontaneous fission (SF) with emission of neutrons.The most common spontaneous fission source is the isotope californium-252. 252 Cf and all other SF neutron sources are made by irradiating uranium or a transuranic element in a nuclear reactor, where neutrons are absorbed in the starting material and its subsequent reaction products, transmuting the starting material into ...
Pages in category "Neutron sources" The following 27 pages are in this category, out of 27 total. This list may not reflect recent changes. ...
Large neutron sources are rare, and usually limited to large-sized devices such as nuclear reactors or particle accelerators, including the Spallation Neutron Source. Neutron radiation was discovered from observing an alpha particle colliding with a beryllium nucleus, which was transformed into a carbon nucleus while emitting a neutron, Be(α, n)C.
The neutron source usually is a research reactor or a spallation source. In some cases, a smaller facility will provide high energy neutrons (e.g. 2.5 MeV or 14 MeV fusion neutrons ) using existing neutron generator technologies.
In practice, the most commonly used small laboratory sources of neutrons use radioactive decay to power neutron production. One noted neutron-producing radioisotope, californium-252 decays (half-life 2.65 years) by spontaneous fission 3% of the time with production of 3.7 neutrons per fission, and is used alone as a neutron source from this ...
This is the main source of tritium from light water reactors. Another source of tritium is Helium-6 which immediately decays to (stable) Lithium-6. Lithium-6 produces tritium when hit by neutrons and is one of the main sources of commercially or militarily produced tritium.
A neutron turbine in which neutrons at 50 m/s are directed against the blades of a turbine wheel with receding tangential velocity 25 m/s, from which neutrons emerge after multiple reflections with a speed of about 5 m/s. [8] [9] [10] After protons are accelerated to around 600 MeV they impinge on a lead target and produce neutrons via spallation.
The neutron energy peaks at around 1 MeV and rapidly drops above. At sea level, the production of neutrons is about 20 neutrons per second per kilogram of material interacting with the cosmic rays (or, about 100–300 neutrons per square meter per second). The flux is dependent on geomagnetic latitude, with a maximum near the magnetic poles.