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Neutron radiation is a form of ionizing radiation that presents as free neutrons.Typical phenomena are nuclear fission or nuclear fusion causing the release of free neutrons, which then react with nuclei of other atoms to form new nuclides—which, in turn, may trigger further neutron radiation.
237 Np is the product of alpha decay of 241 Am, which is produced through neutron irradiation of uranium-238. [28] Heavier isotopes of neptunium decay quickly, and lighter isotopes of neptunium cannot be produced by neutron capture, so chemical separation of neptunium from cooled spent nuclear fuel gives nearly pure 237 Np. [28]
Photofission is a process in which a nucleus, after absorbing a gamma ray, undergoes nuclear fission and splits into two or more fragments.. The reaction was discovered in 1940 by a small team of engineers and scientists operating the Westinghouse Atom Smasher at the company's Research Laboratories in Forest Hills, Pennsylvania. [1]
Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emitting gamma rays , or particles such as beta particles , alpha particles , fission products , and ...
Decay: Outside the nucleus, free neutrons are unstable and have a mean lifetime of 885.7 ± 0.8 s (about 14 minutes, 46 seconds). [1] Free neutrons decay by emission of an electron and an electron antineutrino to become a proton, a process known as beta decay: [2] n 0 → p + + e − + ν e. Although the p + and e −
The neutron has a mean-square radius of about 0.8 × 10 −15 m, or 0.8 fm, [20] and it is a spin-½ fermion. [21] The neutron has no measurable electric charge. With its positive electric charge, the proton is directly influenced by electric fields, whereas the neutron is unaffected by electric fields. [22]
Some early evidence for nuclear fission was the formation of a short-lived radioisotope of barium which was isolated from neutron irradiated uranium (139 Ba, with a half-life of 83 minutes and 140 Ba, with a half-life of 12.8 days, are major fission products of uranium).
Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus. [1] Since neutrons have no electric charge, they can enter a nucleus more easily than positively charged protons , which are repelled electrostatically .