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Gun-type Nuclear Weapon
Gun-type fission weapons are fission-based nuclear weapons whose design assembles their fissile material into a supercritical mass by the use of the "gun" method: shooting one piece of sub-critical material into another. Although this is sometimes pictured as two sub-critical hemispheres driven together to make a supercritical sphere, typically a hollow projectile is shot onto a spike which fills the hole in its center. Its name is a reference to the fact that it is shooting the material through an artillery barrel as if it were a projectile. Since it is a relatively slow method of assembly, plutonium cannot be used unless it is purely the 239 isotope. Production of impurity-free plutonium is very difficult and is impractical. The required amount of uranium is relatively large, and thus the overall efficiency is relatively low. The main reason for this is the uranium metal does not undergo compression (and resulting density increase) as does the implosion design. Instead, gun ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
W9 (nuclear Warhead)
The W9 was an American nuclear artillery shell fired from a special howitzer. It was produced starting in 1952 and all were retired by 1957, being superseded by the W19. Description The W9 was in diameter, long, and weighed . It had an explosive yield of . The W9 was a gun-type nuclear weapon, using around of highly enriched uranium in one large rings assembly and one smaller ''bullet'', which was fired down a tube by conventional explosives into the rings assembly to achieve critical mass and detonate the weapon. The W9 units which were retired in 1957 were recycled into lower yield T-4 Atomic Demolition Munitions. These were the first (semi) man-portable nuclear weapons. Tests The W9 is only the second gun-type nuclear weapon known to have been detonated; the first was the Little Boy nuclear weapon used in World War II. The W9 artillery shell was test fired once, fired from the "Atomic Annie" M65 Atomic Cannon, in ''Upshot-Knothole Grable'' on May 25, 1953 at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Chain Reaction
In nuclear physics, a nuclear chain reaction occurs when one single nuclear reaction causes an average of one or more subsequent nuclear reactions, thus leading to the possibility of a self-propagating series of these reactions. The specific nuclear reaction may be the fission of heavy isotopes (e.g., uranium-235, 235U). A nuclear chain reaction releases several million times more energy per reaction than any chemical reaction. History Chemical chain reactions were first proposed by German chemist Max Bodenstein in 1913, and were reasonably well understood before nuclear chain reactions were proposed. It was understood that chemical chain reactions were responsible for exponentially increasing rates in reactions, such as produced in chemical explosions. The concept of a nuclear chain reaction was reportedly first hypothesized by Hungarian scientist Leó Szilárd on September 12, 1933. Szilárd that morning had been reading in a London paper of an experiment in which protons f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fizzle (nuclear Explosion)
A fizzle occurs when the detonation of a device for creating a nuclear explosion (such as a nuclear weapon) grossly fails to meet its expected yield. The cause(s) for the failure can be linked to improper design, poor construction, or lack of expertise.Staff Writer.NBC Weapons: North Korean Fizzle Bomb" ''Strategy Page.'' Retrieved on 2008-05-04. Earl Lane.Nuclear Experts Assess the Threat of a "Backyard Bomb”" ''American Association for the Advancement of Science.'' Retrieved on 2008-05-04. All countries that have had a nuclear weapons testing program have experienced some fizzles.Meirion Jones.A short history of fizzles" ''BBC News.'' Retrieved on 2008-05-04. A fizzle can spread radioactive material throughout the surrounding area, involve a partial fission reaction of the fissile material, or both.Theodore E. Liolios.The Effects of Nuclear Terrorism: Fizzles" (PDF) ''European Program on Science and International Security.'' Retrieved on 2008-05-04. For practical purposes, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shake (time)
A shake is an informal metric unit of time equal to 10 nanoseconds, or 10−8 seconds. It was originally coined for use in nuclear physics, helping to conveniently express the timing of various events in a nuclear reaction, especially neutron reactions. Etymology Like many informal units having to do with nuclear physics, it arose from top secret operations of the Manhattan Project during World War II. The word "shake" was taken from the idiomatic expression "in two shakes of a lamb's tail", which indicates a very short time interval. Lexicographers have discussed at length that the oldest documented usage of the phrase "two shakes of a lamb's tail" found first (so far) in the works of Richard Barham ; however, the phrase almost certainly was part of vernacular language long before then. Nuclear physics For nuclear-bomb designers, the term was a convenient name for the short interval, rounded to 10 nanoseconds, which was frequently seen in their measurements and calculations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Chain Reaction
In nuclear physics, a nuclear chain reaction occurs when one single nuclear reaction causes an average of one or more subsequent nuclear reactions, thus leading to the possibility of a self-propagating series of these reactions. The specific nuclear reaction may be the fission of heavy isotopes (e.g., uranium-235, 235U). A nuclear chain reaction releases several million times more energy per reaction than any chemical reaction. History Chemical chain reactions were first proposed by German chemist Max Bodenstein in 1913, and were reasonably well understood before nuclear chain reactions were proposed. It was understood that chemical chain reactions were responsible for exponentially increasing rates in reactions, such as produced in chemical explosions. The concept of a nuclear chain reaction was reportedly first hypothesized by Hungarian scientist Leó Szilárd on September 12, 1933. Szilárd that morning had been reading in a London paper of an experiment in which protons f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cordite
Cordite is a family of smokeless propellants developed and produced in the United Kingdom since 1889 to replace black powder as a military propellant. Like modern gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance. These produce a subsonic deflagration wave rather than the supersonic detonation wave produced by brisants, or high explosives. The hot gases produced by burning gunpowder or cordite generate sufficient pressure to propel a bullet or shell to its target, but not so quickly as to routinely destroy the barrel of the gun. Cordite was used initially in the .303 British, Mark I and II, standard rifle cartridge between 1891 and 1915; shortages of cordite in World War I led to the creation of the "Devil's Porridge" munitions factory (HM Factory, Gretna) on the English-Scottish border, which produced 800 tonnes of cordite per annum. The UK also imported some United States–developed smokeless powders for us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide. Uranium-235 has a half-life of 703.8 million years. It was discovered in 1935 by Arthur Jeffrey Dempster. Its fission cross section for slow thermal neutrons is about 584.3±1 barns. For fast neutrons it is on the order of 1 barn. Most but not all neutron absorptions result in fission; a minority result in neutron capture forming uranium-236. Natural decay chain :\begin \ce \begin \ce \\ \ce \end \ce \\ \ce \begin \ce \\ \ce \end \ce \end Fission properties The fission of one atom of uranium-235 releases () inside the reactor. That corresponds to 19.54 TJ/ mol, or 83.14 TJ/kg. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Boy Internal Components (no Labels)
Little is a synonym for small size and may refer to: Arts and entertainment * ''Little'' (album), 1990 debut album of Vic Chesnutt * ''Little'' (film), 2019 American comedy film *The Littles, a series of children's novels by American author John Peterson ** ''The Littles'' (TV series), an American animated series based on the novels Places *Little, Kentucky, United States *Little, West Virginia, United States Other uses *Clan Little, a Scottish clan *Little (surname), an English surname *Little (automobile), an American automobile manufactured from 1912 to 1915 *Little, Brown and Company, an American publishing company * USS ''Little'', multiple United States Navy ships See also * * *Little Mountain (other) *Little River (other) Little River may refer to several places: Australia Streams New South Wales *Little River (Dubbo), source in the Dubbo region, a tributary of the Macquarie River * Little River (Oberon), source in the Oberon Shire, a tributary of Cox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermonuclear Weapon
A thermonuclear weapon, fusion weapon or hydrogen bomb (H bomb) is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a lower mass, or a combination of these benefits. Characteristics of nuclear fusion reactions make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material such as uranium-235 () or plutonium-239 (). The first full-scale thermonuclear test was carried out by the United States in 1952; the concept has since been employed by most of the world's nuclear powers in the design of their weapons. Modern fusion weapons consist essentially of two main components: a nuclear fission primary stage (fueled by or ) and a separate nuclear fusion secondary stage containing thermonuclear fuel: the heavy hydrogen isotopes deuterium and tritium, or in modern weapons lithium deuteride ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boosted Fission Weapon
A boosted fission weapon usually refers to a type of nuclear bomb that uses a small amount of fusion fuel to increase the rate, and thus yield, of a fission reaction. The neutrons released by the fusion reactions add to the neutrons released due to fission, allowing for more neutron-induced fission reactions to take place. The rate of fission is thereby greatly increased such that much more of the fissile material is able to undergo fission before the core explosively disassembles. The fusion process itself adds only a small amount of energy to the process, perhaps 1%. The alternative meaning is an obsolete type of single-stage nuclear bomb that uses thermonuclear fusion on a large scale to create fast neutrons that can cause fission in depleted uranium, but which is not a two-stage hydrogen bomb. This type of bomb was referred to by Edward Teller as "Alarm Clock", and by Andrei Sakharov as "Sloika" or "Layer Cake" (Teller and Sakharov developed the idea independently, as far a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa And Weapons Of Mass Destruction
From the 1960s to the 1990s, South Africa pursued research into weapons of mass destruction, including nuclear, biological, and chemical weapons under the apartheid government. Six nuclear weapons were assembled. South African strategy was, if political and military instability in Southern Africa became unmanageable, to conduct a nuclear weapon test in a location such as the Kalahari desert, where an underground testing site had been prepared, to demonstrate its capability and resolve—and thereby highlight the peril of intensified conflict in the region—and then invite a larger power such as the United States to intervene. Before the anticipated changeover to a majority-elected African National Congress–led government in the 1990s, the South African government dismantled all of its nuclear weapons, the first state in the world which voluntarily gave up all nuclear arms it had developed itself. The country has been a signatory of the Biological Weapons Convention since 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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