fissile
(adjective)
Capable of undergoing nuclear fission.
Examples of fissile in the following topics:
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The Atomic Bomb
- Atomic bombs are made up of a fissile element, such as uranium, that is enriched in the isotope that can sustain a fission nuclear chain reaction.
- When a free neutron hits the nucleus of a fissile atom like uranium-235 (235U), the uranium splits into two smaller atoms called fission fragments, plus more neutrons.
- In fission weapons, a mass of fissile material, either enriched uranium or plutonium, is assembled into a supercritical mass—the amount of material needed to start an exponentially growing nuclear chain reaction.
- The implosion method is considered more sophisticated than the gun method and only can be used if the fissile material is plutonium.
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Nuclear Fission
- The nuclei produced are most often of comparable but slightly different sizes, typically with a mass ratio of products of about 3:2 for common fissile isotopes.
- If an element can be induced to undergo fission via neutron bombardment, it is said to be fissile .
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Nuclear Reactors
- When a large, fissile atomic nucleus such as uranium-235 or plutonium-239 absorbs a neutron, it may undergo nuclear fission.
- A portion of these neutrons may later be absorbed by other fissile atoms and trigger further fission events, which release more neutrons, and so on.
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The Hydrogen Bomb
- The nuclear fusion releases neutrons much faster than a fission reaction, and these neutrons then bombard the remaining fissile fuel, causing it to undergo fission much more rapidly.
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Nuclear Binding Energy and Mass Defect
- As the size of the nucleus increases, the strong nuclear force is only felt between nucleons that are close together, while the coulombic repulsion continues to be felt throughout the nucleus; this leads to instability and hence the radioactivity and fissile nature of the heavier elements.