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Improvised Nuclear Device
Improvised nuclear devices or (INDs) are theoretical illicit nuclear weapons bought, stolen, or otherwise originating from a nuclear state, or a weapon fabricated by a terrorist group from illegally obtained fissile nuclear weapons material that produces a nuclear explosion. An IND could be bought, or it could be built from the components of a stolen weapon or from scratch using nuclear material (plutonium, uranium, or highly enriched uranium). A successful detonation would result in catastrophic loss of life, destruction of infrastructure, and nuclear contamination of a very large area. Types One type of an improvised nuclear device NDattack could be conducted by terrorists with radiological materials using a radiological dispersal device (RDD), or so-called “dirty bomb.” An RDD causes no nuclear explosion but instead uses chemical explosive to spread harmful radioactivity. It could cause severe economic disruption and panic in an urban area, without causing large numbers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). A thermonuclear weapon weighing as little as can release energy equal to more than . A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gun-type Fission 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] |
Mushroom Cloud
A mushroom cloud is a distinctive mushroom-shaped flammagenitus cloud of debris, smoke and usually condensed water vapor resulting from a large explosion. The effect is most commonly associated with a nuclear explosion, but any sufficiently energetic detonation or deflagration will produce the same effect. They can be caused by powerful conventional weapons, like thermobaric weapons, including the ATBIP and GBU-43/B Massive Ordnance Air Blast. Some volcanic eruptions and impact events can produce natural mushroom clouds. Mushroom clouds result from the sudden formation of a large volume of lower-density gases at any altitude, causing a Rayleigh–Taylor instability. The buoyant mass of gas rises rapidly, resulting in turbulent vortices curling downward around its edges, forming a temporary vortex ring that draws up a central column, possibly with smoke, debris, condensed water vapor, or a combination of these, to form the "mushroom stem". The mass of gas plus entrained moist ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Burst
An air burst or airburst is the detonation of an explosive device such as an anti-personnel artillery shell or a nuclear weapon in the air instead of on contact with the ground or target. The principal military advantage of an air burst over a ground burst is that the energy from the explosion (as well as any shell fragments) is distributed more evenly over a wider area; however, the peak energy is lower at ground zero. History Air burst artillery has a long history. The shrapnel shell was invented by Henry Shrapnel of the British Army in about 1780 to increase the effectiveness of canister shot. It was widely used by the time of the War of 1812 and stayed in use until it was superseded during the First World War. Modern shells, though sometimes called "shrapnel shells", actually produce fragments and splinters, not shrapnel. Air bursts were used in the First World War to shower enemy positions and men with shrapnel balls to kill the largest possible number with a sing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groundburst
A ground burst is the detonation of an explosive device such as an artillery shell, nuclear weapon or air-dropped bomb that explodes at ground level. These weapons are set off by fuses that are activated when the weapon strikes the ground or something equally hard, such as a concrete building, or otherwise detonated at the surface. In the context of a nuclear weapon, a ground burst is a detonation on the ground, in shallow water, or below the fallout-free altitude. This condition produces substantial amounts of nuclear fallout. An air burst or a deep subterranean detonation, by contrast, makes little fallout. Ground shock Ground shock, or water shock will result from nuclear explosions on (or near) the surface of ground or water. The ground shock can damage or destroy hardened structures. In water, the shock is damaging to nearby vessels and may also produce a surface wave to limited ranges. A crater is formed by an explosion at (or near) the ground surface. The size of the cra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fizzle (nuclear Test)
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] |
Nuclear Fission
Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay. Nuclear fission of heavy elements was discovered on Monday 19 December 1938, by German chemist Otto Hahn and his assistant Fritz Strassmann in cooperation with Austrian-Swedish physicist Lise Meitner. Hahn understood that a "burst" of the atomic nuclei had occurred. Meitner explained it theoretically in January 1939 along with her nephew Otto Robert Frisch. Frisch named the process by analogy with biological fission of living cells. For heavy nuclides, it is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place). Like nuclear fusion, for fission to produce energy, the total binding energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pit (nuclear Weapon)
The pit, named after the hard core found in fruits such as peaches and apricots, is the core of an implosion nuclear weapon – the fissile material and any neutron reflector or tamper bonded to it. Some weapons tested during the 1950s used pits made with U-235 alone, or in composite with plutonium, but all-plutonium pits are the smallest in diameter and have been the standard since the early 1960s. Pit designs Christy pits The pits of the first nuclear weapons were solid, with an ''urchin'' neutron initiator in their center. The Gadget and Fat Man used pits made of 6.2 kg of solid hot pressed plutonium-gallium alloy (at 400 °C and 200 MPa in steel dies – and ) half-spheres of diameter, with a internal cavity for the initiator. The Gadget's pit was electroplated with 0.13 mm of silver; the layer, however, developed blistering and the blisters had to be ground and plated with gold leaf before the test. The Fat Man pit, and those of subsequent models, were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fallout
Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes. The amount and spread of fallout is a product of the size of the weapon and the altitude at which it is detonated. Fallout may get entrained with the products of a pyrocumulus cloud and fall as black rain (rain darkened by soot and other particulates, which fell within 30–40 minutes of the atomic bombings of Hiroshima and Nagasaki). This radioactive dust, usually consisting of fission products mixed with bystanding atoms that are neutron-activated by exposure, is a form of radioactive contamination. Types of fallout Fallout comes in two varieties. The first is a small amount of carcinogenic material with a long half-life. The second, depending on the height of detonation, is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CNBC
CNBC (formerly Consumer News and Business Channel) is an American basic cable business news channel. It provides business news programming on weekdays from 5:00 a.m. to 7:00 p.m., Eastern Time, while broadcasting talk shows, investigative reports, documentaries, infomercials, reality shows, and other programs at all other times. Along with Fox Business and Bloomberg Television, it is one of the three major business news channels. It also operates a website and mobile apps, whereby users can watch the channel via streaming media, and which provide some content that is only accessible to paid subscribers. CNBC content is available on demand on smart speakers including Amazon Echo devices with Amazon Alexa, Google Home and app devices with Google Assistant, and on Apple Siri voice interfaces including iPhones. Many CNBC TV shows are available as podcasts for on-demand listening. Graphics are designed by Sweden-based Magoo 3D studios. CNBC is a divisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrorist Group
A number of national governments and two international organizations have created lists of organizations that they designate as terrorist. The following list of designated terrorist groups lists groups designated as terrorist by current and former national governments, and inter-governmental organizations. Such designations have often had a significant effect on the groups' activities. Many organizations that have been designated as terrorist have denied using terrorism as a military tactic to achieve their goals, and there is no international consensus on the legal definition of terrorism. Some organisations have multiple wings or components, one or more of which may be designated as terrorist while others are not. This listing does not include unaffiliated individuals accused of terrorism, which is considered lone wolf terrorism. This list also excludes groups which might be widely considered terrorist, but who are not officially so designated according to the criteria specif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pure Fusion Weapon
A pure fusion weapon is a hypothetical hydrogen bomb design that does not need a fission "primary" explosive to ignite the fusion of deuterium and tritium, two heavy isotopes of hydrogen used in fission-fusion thermonuclear weapons. Such a weapon would require no fissile material and would therefore be much easier to develop in secret than existing weapons. Isotope separation, Separating weapons-grade uranium (U-235) or breeding plutonium (Pu-239) requires a substantial and difficult-to-conceal industrial investment, and blocking the sale and transfer of the needed machinery has been the primary mechanism to control nuclear proliferation to date. Explanation All current 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 low ...s use a fission bomb as a first stage to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
