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Interaction of Radiation with Matter
Published in William H. Hallenbeck, Radiation Protection, 2020
Interactions of neutrons with matter is different from that of charged particles and photons. The principal interaction of neutrons is with nuclei (interaction with electrons is very weak). Interaction with target nuclei produces scattered neutrons or neutron capture. The notation for these interactions is as follows: neutron scatter reactions: (n,n), (n,n′), and (n,n′γ)neutron capture reactions: (n,γ), (n,p), (n,α), (n,d), (n,t), (n,f), and (n,2n)
The radiation background
Published in R.J. Pentreath, Nuclear Power, Man and the Environment, 2019
The neutron flux results not only in fissions of other uranium nuclei; neutrons may also be captured by the materials of the bomb casing and by debris sucked into the fireball which results from the explosion. The isotopes of many elements may thereby be made radioactive by neutron capture: these are the neutron activation products. Typical of such radionuclides are those of elements such as iron, zinc, manganese and cobalt – all of which are essential trace elements. The type, and amounts, of neutron activation products formed will depend upon where, and at what height, the bomb was exploded. Elements in the atmosphere are also subject to neutron interactions, notably nitrogen, which produces some 1.26 PBq (34 kCi) of 14C per megaton. A much smaller amount of 3H is also produced.
Ionizing Radiation
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Neutron capture reactions tend to occur with slow or thermal neutrons. Neutron capture is the process where a neutron is absorbed into the nucleus and a second particle is emitted, such as a proton or alpha particle. Usually, the resultant nucleus is radioactive. Neutron capture, also called neutron activation, is the mechanism for the production of most of the commercially available radionuclides. Neuron activation also results in unwanted induced radioactivity in and around nuclear reactors. An example of neutron capture is the reaction which naturally creates C-14 in the earth’s atmosphere from nitrogen and cosmic neutrons: () N14(n,p)14C
Relevance of Tritium Breeder Irradiation Testing in a Fusion Prototypic Neutron Source
Published in Fusion Science and Technology, 2023
Chase N. Taylor, Matthew D. Eklund, Thomas F. Fuerst, Masashi Shimada, Paul W. Humrickhouse, Tim Bohm
Neutron capture can result in elemental transmutation. Capture cross sections increase at lower neutron energies for most elements. The neutron capture cross sections for blanket materials are shown in Figs. 4e and 4f. Because of the higher cross sections at thermal energies compared to fusion energies, more transmutation elements are produced with thermal neutrons.