NUCLEAR FISSION
Nuclear fission is a reaction in which an atom's nucleus is broken apart, releasing a tremendous amount of energy. Nuclear fission is used in many power plants on Earth (and is used in atomic weapons).
nuclear fission: Reaction that splits nuclei into less massive fragments.
nuclear fusion: Reaction that joins the nuclei of atoms to form more massive nuclei.
Nuclear fission The breaking up of a heavy nucleus in two parts of comparable masses, typically, 1/3 and 2/3 of the original mass, associated with a great release of energy.
A natural nuclear fission reactor is a uranium mineral deposit where analysis of isotope ratios has shown that self-sustaining nuclear chain reactions have occurred....
. Self-sustaining nuclear fission
Nuclear fission ...
nuclear fission - (n.)
The splitting of an atomic nucleus into two large fragments.
nuclear fusion - (n.) ...
Nuclear fission reactors naturally produce free neutrons; their role is to sustain the energy-producing chain reaction.
Nuclear fission
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Theoretical astronomers use a wide variety of tools which include analytical models (for example, polytropes to approximate the behaviors of a star) and computational numerical simulations. Each has some advantages.
Heat from JIMO's nuclear fission reactor would be converted to electricity, giving the probe more than 100 times as much power as a non-fission system of comparable weight.
nuclear devices (NASA Thesaurus) Devices whose explosive potency is derived from nuclear fission of atoms of fissionable material with the consequent conversion of part of their mass into energy.
The subsequent nucleosynthesis of the elements occurs primarily either by nuclear fusion or nuclear fission.
History ...
The process of nuclear fusion is related to but different from the process of nuclear fission wherein large atoms are broken apart and the resulting pieces have less mass than the original atom.
It is easy to show the fallacy of the linear no-threshold relationship: Background radiation in our everyday environment does not kill people, yet radiation blasts from nuclear fission events (e.g. worst-case meltdowns or nearby atomic bombs) can ...
Of the various processes resulting in the production of radioactive species, neutron-induced nuclear fission, achieved in 1939, has been the most fruitful. In 1941 it was learned that fission may also occur spontaneously.
Acting like a natural, fast-breeder nuclear fission reactor, the sub-core generates heat that propels charged particles to ultimately produce the Earth's magnetic field in a non-linear process that periodically weakens and strengthens, ...
Future interplanetary missions of the Prometheus Project, including JIMO, the Jupiter Icy Moons Orbiter, are planning to use nuclear fission reactors to produce hundreds of times more electrical power than today's spacecraft, ...
of science fiction have depicted spaceships running on antimatter reactions, but Bickford, as part of a study for NASA's Institute for Advanced Concepts (see here for more), has looked at how antiprotons could instead instigate nuclear fission ...
Fission, Nuclear: The release of nuclear energy by the breaking apart of large, heavy elements (e.g. Uranium) into two or more smaller atoms. Nuclear fission is the basis for so-called A bombs, and for nuclear power reactors.
After the star enters the main sequence stage, energy comes from nuclear fusion, the combination of several small nuclei into a large nucleus. In contrast, the nuclear plants on Earth generate energy by nuclear fission, ...
The change happens spontaneously, without any external influence. This instability is known as radioactivity. The energy released by the disintegration of the radioactive elements just listed is the basis for nuclear fission reactors (and nuclear ...
The most tightly bound isotopes are 62Ni, 58Fe, and 56Fe, which have binding energies of 8.8 MeV per nucleon. Elements heavier than these isotopes can yield energy by nuclear fission; lighter isotopes can yield energy by fusion.
nuclear reactor An apparatus in which nuclear fission may be sustained in a self supporting chain reaction. Commonly called reactor. Formerly called pile.
 See also: Fission, Energy, Light, Fusion, Earth
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