| neutron | <physics> An elementary atomic particle that has no charge and a mass that is approximately the same as that of a proton. Neutrons are found in allatoms except the lightest isotopes of hydrogen. (09 Jan 1998) |
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| neutron activation analysis | Activation analysis in which the specimen is bombarded with neutrons. Identification is made by measuring the resulting radioisotopes. (12 Dec 1998) |
| neutron capture therapy | A technique for the treatment of neoplasms in which an isotope is introduced into target cells followed by irradiation with thermal neutrons. (12 Dec 1998) |
| neutron radiation | An emission of neutrons from the nucleus of an atom by decay or fission. (05 Mar 2000) |
| neutrons | Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay. (12 Dec 1998) |
| boron neutron capture therapy | A technique for the treatment of neoplasms, especially gliomas and melanomas in which boron-10, an isotope, is introduced into the target cells followed by irradiation with thermal neutrons. (12 Dec 1998) |
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| integrated neutron flux | <radiobiology> Sum (integral) of the neutron flux (neutrons per unit time per unit area, see flux) over all time, total number of neutrons which passed through a unit area. Important figure-of-merit in testing effects of neutron radiation on materials, and in assessing how long such materials can survive exposure to neutron sources (such as fission reactor cores and D-T fusion plasmas). (09 Oct 1997) |
| thermal neutron | <radiobiology> A neutron in thermal equilibrium with its surrounding environment. Thermal neutrons are those that have been slowed down by a moderator to speeds characteristic of the local temperature. Compare: fast neutron. (09 Oct 1997) |
| fast neutron | <physics> Neutron with energy greater than roughly 100,000 electron volts (100 keV). Distinguished from slow or thermal neutrons. (09 Oct 1997) |