Although two to three neutrons are produced for every fission, not all of these neutrons are available for continuing the fission reaction. ... At the point where the chain reaction can become self-sustaining, this is referred to as critical mass. ... Lawrence Berkeley National Laboratory: The ABC's of Nuclear Science...
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Critical mass - Wikipedia, the free encyclopedia
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A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (e.g. the nu...
en.wikipedia.org/wiki/Critical_mass
Nuclear fission - Wikipedia, the free encyclopedia
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In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts, often producing free neutrons and lighter nuclei, which may...
en.wikipedia.org/wiki/Nuclear_fission
The term critical mass does not relate to nuclear fusion. Nuclear fusion is the fusing, the joining, of two or more nucleons or nuclei to create a heavier nucleus. It takes enormous energy to set up the conditions that will make this happen...
http://wiki.answers.com/Q/In_respect_to_nuclear_fission...
Critical mass (nuclear); Critical Mass (pressure group); Critical Mass (rock band); Critical Mass (short story); Critical Mass (ska band); Critical Mass (Ska); Critical mass (sociodynamics); Critical mass (software); Critical Mass (Stargate Atlantis);
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­Critical mass: If, on average, exactly one of the free neutrons from each fission hits another U-235 nucleus and causes it to split, then the mass of uranium ... In designing a nuclear bomb, engineers need the mass of uranium to be very supercritical so that all of the U-235 atoms in the mass split in a single microsecond.
science.howstuffworks.com/nuclear-power2.htm science.howstuffworks.com/nuclear-power2.htm
surrounded by neutron-reflecting blocks of Tungsten Carbide . A re-creation of a 1945 Criticality Accident to measure the radiation produced when an extra block was added, making the mass supercritical.]]The critical mass of Fissile material is the amount needed for a sustained Nuclear Chain Reaction . The critical mass of ...
www.seattleluxury.com/encyclopedia/entry/Critical_mass_... www.seattleluxury.com/encyclopedia/entry/Critical_mass_(nuclear)
For a chain reaction of nuclear fission, such as that of uranium-235, is to sustain itself, then at least one neutron from each fission must strike another U-235 nucleus and cause a fission. If this condition is just met, then the reaction is said to be "critical" and will continue.
hyperphysics.phy-astr.gsu.edu/hbase/nucene/moder.html
Because of the presence of stray neutrons in the atmosphere or the possibility of their being generated in various ways, a quantity of a suitable isotope of uranium (or plutonium) exceeding the critical mass would be likely to melt or possibly explode. ... BOMB SHELTER & NUCLEAR BOMB NEWS ... Critical Mass for a Fission Chain;
www.undergroundbombshelter.com/bombshelter/understandin... www.undergroundbombshelter.com/bombshelter/understanding-radiation-scientific-basis-nuclear-explosion-attainment-critical-mass-nuclear-weapons.htm
Critical Mass for a Fission Chain; Although two to three neutrons are produced in the fission reaction for every nucleus that undergoes fission, not all of these neutrons are available for causing further fissions. ... Attainment of Critical Mass in a Nuclear Explosion; In order to produce an explosion,
www.undergroundbombshelter.com/bombshelter/understandin... www.undergroundbombshelter.com/bombshelter/understanding-radiation-scientific-basis-nuclear-explosion-critical-mass-fission-chain.htm