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W49(N)
The W49 was an American thermonuclear warhead, used on the Thor, Atlas, Jupiter, and Titan I ballistic missile systems. W49 warheads were manufactured starting in 1958 and were in service until 1965, with a few warheads being retained until 1975. The weapon itself was a Mark 28 Y1 warhead modified for the missile role. History Initial development of the Mod 0 warhead Development began in mid-1956 with the need for a warhead for the then in development Thor, Atlas, Jupiter and Titan missiles. This led to work being performed to develop the XW-35 and XW-35-X1 warheads, with the high-yield, improved X1 to enter service approximately one year after the XW-35. However, development of these missiles was delayed and it became apparent to designers that the planned service entry date for the XW-35-X1 would now be the same as the missiles (except for Jupiter), leading to the cancellation of the XW-35 and the decision to fit XW-28 warheads to Jupiter as an interim warhead until the XW-35 ... [...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] |
Half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential (or, rarely, non-exponential) decay. For example, the medical sciences refer to the biological half-life of drugs and other chemicals in the human body. The converse of half-life (in exponential growth) is doubling time. The original term, ''half-life period'', dating to Ernest Rutherford's discovery of the principle in 1907, was shortened to ''half-life'' in the early 1950s. Rutherford applied the principle of a radioactive element's half-life in studies of age determination of rocks by measuring the decay period of radium to lead-206. Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristic unit for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starfish Prime
Starfish Prime was a high-altitude nuclear test conducted by the United States, a joint effort of the Atomic Energy Commission (AEC) and the Defense Atomic Support Agency. It was launched from Johnston Atoll on July 9, 1962, and was the largest nuclear test conducted in outer space, and one of five conducted by the US in space. A Thor rocket carrying a W49 thermonuclear warhead (designed at Los Alamos Scientific Laboratory) and a Mk. 2 reentry vehicle was launched from Johnston Atoll in the Pacific Ocean, about west-southwest of Hawaii. The explosion took place at an altitude of , above a point southwest of Johnston Atoll. It had a yield of . The explosion was about 10° above the horizon as seen from Hawaii, at 11 pm Hawaii time. Operation Fishbowl The Starfish test was one of five high-altitude tests grouped together as Operation Fishbowl within the larger Operation Dominic, a series of tests in 1962 begun in response to the Soviet announcement on August 30, 1961, tha ... [...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] |
Program 437
Program 437 was the second anti-satellite weapons program of the U.S. military.Peebles, Curtis. "High Frontier: The United States Air Force and the Military Space Program", 1997 The US anti-satellite weapons program began development in the early 1960s and was officially discontinued on 1 April 1975. Program 437 was approved for development by U.S. Secretary of Defense Robert McNamara on November 20, 1962, after a series of tests involving high altitude nuclear explosions. The program's facilities were located on Johnston Island, an isolated island in the north central Pacific Ocean. History The US's first anti-satellite system was Program 505, based at the Kwajalein Missile Range, about halfway between Hawaii and the Philippine islands. This system became operational in 1962, based on the Nike Zeus anti-ballistic missile that had been tested at that site. These missiles had been modified for greater range, but even with these modifications the system could only intercept sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permissive Action Link
A permissive action link (PAL) is an access control security device for nuclear weapons. Its purpose is to prevent unauthorized arming or detonation of a nuclear weapon. The United States Department of Defense definition is: The earliest PALs were little more than locks introduced into the control and firing systems of a nuclear weapon, that would inhibit either the detonation, or the removal of safety features of the weapon. More recent innovations have included encrypted firing parameters, which must be decrypted to properly detonate the warhead, plus anti-tamper systems which intentionally mis-detonate the weapon, destroying it without giving rise to a nuclear explosion. History Background Permissive action links were developed in the United States in a gradual process from the first use of atomic weapons to the early 1960s. In 1953 the United States Atomic Energy Commission and the Department of Defense signed the ''Missiles and Rockets Agreement'', which paved t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Generator
Neutron generators are neutron source devices which contain compact linear particle accelerators and that produce neutrons by fusing isotopes of hydrogen together. The fusion reactions take place in these devices by accelerating either deuterium, tritium, or a mixture of these two isotopes into a metal hydride target which also contains deuterium, tritium or a mixture of these isotopes. Fusion of deuterium atoms (D + D) results in the formation of a helium-3 ion and a neutron with a kinetic energy of approximately 2.5 MeV. Fusion of a deuterium and a tritium atom (D + T) results in the formation of a helium-4 ion and a neutron with a kinetic energy of approximately 14.1 MeV. Neutron generators have applications in medicine, security, and materials analysis. The basic concept was first developed by Ernest Rutherford's team in the Cavendish Laboratory in the early 1930s. Using a linear accelerator driven by a Cockcroft–Walton generator, Mark Oliphant led an experiment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KAERI
The Korea Atomic Energy Research Institute (KAERI) in Daejeon, South Korea was established in 1959 as the sole professional research-oriented institute for nuclear power in South Korea, and has rapidly built a reputation for research and development in various fields. In 1995 KAERI designed and constructed the nation's first multipurpose research reactor, HANARO based on the Canadian MAPLE design. KAERI is dedicated to finding a wide range of uses for atomic energy. As examples, KAERI developed the world's first radiopharmaceutical "Milican injection" for treating liver cancer. KAERI has made significant contributions to the nation's nuclear technology development. After Korea achieved self-reliance in nuclear core technologies, KAERI have transferred highly developed technologies to local industries for practical applications. The Korea Institute of Nuclear Safety (KINS), responsible for supporting the government in regulatory and licensing works, and the Nuclear Environment Tec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polonium-210
Polonium-210 (210Po, Po-210, historically radium F) is an isotope of polonium. It undergoes alpha decay to stable 206Pb with a half-life of 138.376 days (about months), the longest half-life of all naturally occurring polonium isotopes. First identified in 1898, and also marking the discovery of the element polonium, 210Po is generated in the decay chain of uranium-238 and radium-226. 210Po is a prominent contaminant in the environment, mostly affecting seafood and tobacco. Its extreme toxicity is attributed to intense radioactivity, capable of severely harming humans. History In 1898, Marie and Pierre Curie discovered a strongly radioactive substance in pitchblende and determined that it was a new element; it was one of the first radioactive elements discovered. Having identified it as such, they named the element polonium after Marie's home country, Poland. Willy Marckwald discovered a similar radioactive activity in 1902 and named it radio-tellurium, and at roughly the sa ... [...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] |
Modulated Neutron Initiator
A modulated neutron initiator is a neutron source capable of producing a burst of neutrons on activation. It is a crucial part of some nuclear weapons, as its role is to "kick-start" the chain reaction at the optimal moment when the configuration is prompt critical. It is also known as an internal neutron initiator. The initiator is typically placed in the center of the plutonium pit, and is activated by impact of the converging shock wave. One of the key elements in the proper operation of a nuclear weapon is initiation of the fission chain reaction at the proper time. To obtain a significant nuclear yield, sufficient neutrons must be present within the supercritical core at the right time. If the chain reaction starts too soon (" predetonation"), the result will be only a ' fizzle yield', well below the design specification. If it occurs too late, the core will have begun to expand and disassemble into a less-dense state, leading to a lowered yield (less of the core material unde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B28 Nuclear Bomb
The B28, originally Mark 28, was a thermonuclear bomb carried by U.S. tactical fighter bombers, attack aircraft and bomber aircraft. From 1962 to 1972 under the NATO nuclear weapons sharing program, American B28s also equipped six Europe-based Canadian CF-104 squadrons known as the RCAF Nuclear Strike Force. It was also supplied for delivery by UK-based Royal Air Force Valiant and Canberra aircraft assigned to NATO under the command of SACEUR. In addition, certain U.S. Navy carrier based attack aircraft such as the A3D (later A-3B) Skywarrior, A4D (later A-4) Skyhawk, and A3J (later A-5A) Vigilante were equipped to carry the B28. Production history Initial development of the IN and EX weapons During the design of the TX-15 in 1953 it became evident to designers that massive reductions in size and weight of thermonuclear weapons were possible. In November 1954 the TX-Theta Committee proposed the development of the WX-27 and the WX-28. The larger diameter TX-27 was intend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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