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Neutron activation is the only common way that a stable material can be induced into becoming intrinsically radioactive. All naturally occurring materials, including air, water, and soil, can be induced (activated) by neutron capture into some amount of radioactivity in varying degrees, as a result of the production of neutron-rich radioisotopes.
Neutron activation analysis (NAA) is a nuclear process used for determining the concentrations of elements in many materials. NAA allows discrete sampling of elements as it disregards the chemical form of a sample, and focuses solely on atomic nuclei. The method is based on neutron activation and thus requires a neutron source.
The 152 Eu (half life 13.54 year) and 154 Eu (half life 8.59 year) were mainly formed by the neutron activation of the europium in the soil, it is clear that the level of radioactivity for these isotopes is highest where the neutron dose to the soil was larger.
By neutron irradiation of objects, it is possible to induce radioactivity; this activation of stable isotopes to create radioisotopes is the basis of neutron activation analysis. A high-energy most interesting object which has been studied in this way is the hair of Napoleon's head, which has been examined for its arsenic content. [1]
An activation product is a material that has been made radioactive by the process of neutron activation.. Fission products and actinides produced by neutron absorption of nuclear fuel itself are normally referred to by those specific names, and activation product reserved for products of neutron capture by other materials, such as structural components of the nuclear reactor or nuclear bomb ...
R-process describes neutron capture in a region of high neutron flux, such as during supernova nucleosynthesis after core-collapse, and yields neutron-rich nuclides. S-process describes neutron capture that is slow relative to the rate of beta decay , as for stellar nucleosynthesis in some stars, and yields nuclei with stable nuclear shells .
A fixed source calculation involves imposing a known neutron source on a medium and determining the resulting neutron distribution throughout the problem. This type of problem is particularly useful for shielding calculations, where a designer would like to minimize the neutron dose outside of a shield while using the least amount of shielding ...
This process happens when an energetic particle from radioactive decay, often an alpha particle, reacts with a nucleus of another atom to change the nucleus into another nuclide. This process may also cause the production of further subatomic particles, such as neutrons. Neutrons can also be produced in spontaneous fission and by neutron emission.