The (n-p) reaction, or (n,p) reaction, is an example of a nuclear reaction. It is the reaction which occurs when a neutron enters a nucleus and a proton leaves the nucleus simultaneously.[1]
For example, sulfur-32 (32S) undergoes an (n,p) nuclear reaction when bombarded with neutrons, thus forming phosphorus-32 (32P).
The nuclide nitrogen-14 (14N) can also undergo an (n,p) nuclear reaction to produce carbon-14 (14C). This nuclear reaction 14N (n,p) 14C continually happens in the Earth's atmosphere, forming equilibrium amounts of the radionuclide 14C.
Most (n,p) reactions have threshold neutron energies below which the reaction cannot take place as a result of the charged particle in the exit channel requiring energy (usually more than a MeV) to overcome the Coulomb barrier experienced by the emitted proton. The (n,p) nuclear reaction 14N (n,p) 14C is an exception to this rule, and is exothermic – it can take place at all incident neutron energies. The 14N (n,p) 14C nuclear reaction is responsible for most of the radiation dose delivered to the human body by thermal neutrons – these thermal neutrons are absorbed by the nitrogen 14N in proteins, causing a proton to be emitted; the emitted proton deposits its kinetic energy over a very short distance in the body tissue, thereby depositing radiation dose.
References
Jha, D. K. (2004). Elements Of Nuclear Reactors. Discovery Publishing House. p. 65. ISBN 978-81-7141-883-1.
vte
Nuclear processes
Radioactive decay
Alpha decay Beta decay Gamma radiation Cluster decay Double beta decay Double electron capture Internal conversion Isomeric transition Neutron emission Positron emission Proton emission Spontaneous fission
Deuterium fusion Lithium burning pp-chain CNO cycle α process Triple-α C burning Ne burning O burning Si burning r-process s-process p-process rp-process
Other
processes
Photodisintegration Photofission
Capture
Electron capture Neutron capture Proton capture
Exchange
Hellenica World - Scientific Library
Retrieved from "http://en.wikipedia.org/"
All text is available under the terms of the GNU Free Documentation License