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Operation Upshot–Knothole
Operation Upshot–Knothole was a series of eleven nuclear test shots conducted in 1953 at the Nevada Test Site. It followed ''Operation Ivy'' and preceded ''Operation Castle''. Over 21,000 soldiers took part in the ground exercise Desert Rock V in conjunction with the ''Grable'' shot. , Defense Threat Reduction Agency ''Grable'' was a 280mm Artillery Fired Atomic Projectile (AFAP) shell fired from the "M65 atomic cannon, Atomic Cannon" and was viewed by a number of high-ranking military officials. The test series was notable as containing the first time an AFAP shell was fired (''GRABLE'' Shot), the first two shots (both Fizzle (nuclear test), fizzles) by University of California Radiation Laboratory—Livermore (now Lawrence Livermore National Laboratory), and for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Time
Universal Time (UT or UT1) is a time standard based on Earth's rotation. While originally it was mean solar time at 0° longitude, precise measurements of the Sun are difficult. Therefore, UT1 is computed from a measure of the Earth's angle with respect to the International Celestial Reference Frame (ICRF), called the Earth Rotation Angle (ERA, which serves as a modern replacement for Greenwich Mean Sidereal Time). UT1 is the same everywhere on Earth. UT1 is required to follow the relationship :ERA = 2π(0.7790572732640 + 1.00273781191135448'' · Tu'') radians where ''Tu'' = ( Julian UT1 date - 2451545.0). History Prior to the introduction of standard time, each municipality throughout the clock-using world set its official clock, if it had one, according to the local position of the Sun (see solar time). This served adequately until the introduction of rail travel in Britain, which made it possible to travel fast enough over long distances to require continuous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium Hydride Bomb
The uranium hydride bomb was a variant design of the atomic bomb first suggested by Robert Oppenheimer in 1939 and advocated and tested by Edward Teller. It used deuterium, an isotope of hydrogen, as a neutron moderator in a uranium-deuterium ceramic compact. Unlike all other fission-based weapon types, the concept relies on a chain reaction of slow nuclear fission (see neutron temperature). Bomb efficiency was adversely affected by the cooling of neutrons since the latter delays the reaction, as delineated by Rob Serber in his 1992 extension of the original ''Los Alamos Primer''. The term hydride for this type of weapons has been subject to misunderstandings in the open literature. While the "hydride" might erroneously imply that the isotope used is hydrogen, only deuterium has been used for the bomb pits. The nomenclature is used in a manner similar to the term "hydrogen bomb", where the latter employs deuterium and occasionally tritium. Two uranium deuteride fueled bombs are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mark 5 Nuclear Bomb
The Mark 5 nuclear bomb and W5 nuclear warhead were a common core American nuclear weapon design, designed in the early 1950s and which saw service from 1952 to 1963. Description The Mark 5 design was the first production American nuclear weapon which, with a diameter of , was significantly smaller than the diameter implosion system of the 1945 Fat Man nuclear bomb design. The Mark 5 design used a 92-point implosion system (see Nuclear weapon design) and a composite uranium/plutonium fissile material core or pit. The Mark 5 core and W5 warhead were in diameter and long; the total Mark 5 bomb had a diameter of and was long. The different versions of Mark 5 weighed ; the W5 versions weighed . The Mark 5 and W5 were pure fission weapons. There were at least four basic models of core design used, and sub-variants with yields of 6, 16, 55, 60, 100, and 120 kilotons have been reported. As with many early US nuclear weapon designs, the fissile material or pit could be kept separ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevada National Security Site
The Nevada National Security Site (N2S2 or NNSS), known as the Nevada Test Site (NTS) until 2010, is a United States Department of Energy (DOE) reservation located in southeastern Nye County, Nevada, about 65 miles (105 km) northwest of the city of Las Vegas. Formerly known as the Nevada Proving Grounds, the site was established in 1951 for the testing of nuclear devices. It covers approximately 1,360 square miles (3,500 km2) of desert and mountainous terrain. Nuclear weapons testing at the site began with a 1-kiloton-of-TNT (4.2 TJ) bomb dropped on Frenchman Flat on January 27, 1951. Over the subsequent four decades, over 1,000 nuclear explosions were detonated at the site. Many of the iconic images of the nuclear era come from the site. During the 1950s, the mushroom clouds from the 100 atmospheric tests could be seen from almost away. The city of Las Vegas experienced noticeable seismic effects, and the mushroom clouds, which could be seen from the downtown hot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upshot-Knothole Annie
Upshot–Knothole ''Annie'' was a nuclear weapons test conducted by the United States as part of Operation Upshot–Knothole. It took place at the Nevada Test Site on 17 March 1953, and was nationally televised. The live TV coverage was recorded on a kinescope Kinescope , shortened to kine , also known as telerecording in Britain, is a recording of a television program on motion picture film, directly through a lens focused on the screen of a video monitor. The process was pioneered during the 194 ..., so it is a rare record of the sound an actual atomic bomb makes. Operation Doorstep was a civil defense study conducted by the Federal Civil Defense Administration in conjunction with ''Annie''. It studied the effect of the nuclear blast on two wooden frame houses, fifty automobiles and eight bomb shelters designed for residential use. The administration concluded that a car would be "relatively safe" from a small nuclear bomb at least ten blocks away if windows were left o ... [...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] |
TNT Equivalent
TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a metric ton (1,000 kilograms) of TNT. In other words, for each gram of TNT exploded, (or 4184 joules) of energy is released. This convention intends to compare the destructiveness of an event with that of conventional explosive materials, of which TNT is a typical example, although other conventional explosives such as dynamite contain more energy. Kiloton and megaton The "kiloton (of TNT)" is a unit of energy equal to 4.184 terajoules (). The "megaton (of TNT)" is a unit of energy equal to 4.184 petajoules (). The kiloton and megaton of TNT have traditionally been used to describe the energy output, and hence the destructive power, of a nuclear weapon. The TNT equivalent appears in various nuclear weapon control treaties, and has b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Weapon Yield
The explosive yield of a nuclear weapon is the amount of energy released when that particular nuclear weapon is detonated, usually expressed as a TNT equivalent (the standardized equivalent mass of trinitrotoluene which, if detonated, would produce the same energy discharge), either in kilotonnes (kt—thousands of tonnes of TNT), in megatonnes (Mt—millions of tonnes of TNT), or sometimes in terajoules (TJ). An explosive yield of one terajoule is equal to . Because the accuracy of any measurement of the energy released by TNT has always been problematic, the conventional definition is that one kilotonne of TNT is held simply to be equivalent to 1012 calories. The yield-to-weight ratio is the amount of weapon yield compared to the mass of the weapon. The practical maximum yield-to-weight ratio for fusion weapons (thermonuclear weapons) has been estimated to six megatonnes of TNT per tonne of bomb mass (25 TJ/kg). Yields of 5.2 megatonnes/tonne and higher have been reported ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Nuclear Weapons
This is a list of nuclear weapons listed according to country of origin, and then by type within the states. United States US nuclear weapons of all types – bombs, warheads, shells, and others – are numbered in the same sequence starting with the Mark 1 and () ending with the W-91 (which was canceled prior to introduction into service). All designs which were formally intended to be weapons at some point received a number designation. Pure test units which were experiments (and not intended to be weapons) are not numbered in this sequence. Early weapons were very large and could only be used as free fall bombs. These were known by "Mark" designators, like the Mark 4 which was a development of the Fat Man weapon. As weapons became more sophisticated they also became much smaller and lighter, allowing them to be used in many roles. At this time the weapons began to receive designations based on their role; bombs were given the prefix "B", while the same warhead used in other r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Nuclear Test Ban Treaty
The Partial Test Ban Treaty (PTBT) is the abbreviated name of the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, which prohibited all test detonations of nuclear weapons except for those conducted underground. It is also abbreviated as the Limited Test Ban Treaty (LTBT) and Nuclear Test Ban Treaty (NTBT), though the latter may also refer to the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which succeeded the PTBT for ratifying parties. Negotiations initially focused on a comprehensive ban, but that was abandoned because of technical questions surrounding the detection of underground tests and Soviet concerns over the intrusiveness of proposed verification methods. The impetus for the test ban was provided by rising public anxiety over the magnitude of nuclear tests, particularly tests of new thermonuclear weapons (hydrogen bombs), and the resulting nuclear fallout. A test ban was also seen as a means of slowing nuclear proliferati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elevation
The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vertical datum). The term ''elevation'' is mainly used when referring to points on the Earth's surface, while ''altitude'' or ''geopotential height'' is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, and '' depth'' is used for points below the surface. Elevation is not to be confused with the distance from the center of the Earth. Due to the equatorial bulge, the summits of Mount Everest and Chimborazo have, respectively, the largest elevation and the largest geocentric distance. Aviation In aviation the term elevation or aerodrome elevation is defined by the ICAO as the highest point of the landing area. It is often measured in feet and can be found in approach charts of the aerodrome. It is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
