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Little Boy
"Little Boy" was the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II, making it the first nuclear weapon used in warfare. The bomb was dropped by the Boeing B-29 Superfortress ''Enola Gay'' piloted by Colonel Paul W. Tibbets, Jr., commander of the 509th Composite Group of the United States Army Air Forces and Captain Robert A. Lewis. It exploded with an energy of approximately and caused widespread death and destruction throughout the city. The Hiroshima bombing was the second man-made nuclear explosion in history, after the Trinity nuclear test. Little Boy was developed by Lieutenant Commander Francis Birch (geophysicist), Francis Birch's group at the Manhattan Project's Los Alamos Laboratory during World War II, a reworking of their unsuccessful Thin Man (nuclear bomb), Thin Man nuclear bomb. Like Thin Man, it was a gun-type fission weapon, but it derived its explosive power from the nuclear fission of uranium-235, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Boy
"Little Boy" was the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II, making it the first nuclear weapon used in warfare. The bomb was dropped by the Boeing B-29 Superfortress ''Enola Gay'' piloted by Colonel Paul W. Tibbets, Jr., commander of the 509th Composite Group of the United States Army Air Forces and Captain Robert A. Lewis. It exploded with an energy of approximately and caused widespread death and destruction throughout the city. The Hiroshima bombing was the second man-made nuclear explosion in history, after the Trinity nuclear test. Little Boy was developed by Lieutenant Commander Francis Birch (geophysicist), Francis Birch's group at the Manhattan Project's Los Alamos Laboratory during World War II, a reworking of their unsuccessful Thin Man (nuclear bomb), Thin Man nuclear bomb. Like Thin Man, it was a gun-type fission weapon, but it derived its explosive power from the nuclear fission of uranium-235, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin Man (nuclear Bomb)
"Thin Man" was the code name for a proposed plutonium gun-type nuclear bomb that the United States was developing during the Manhattan Project. Its development was abandoned when it was discovered that the spontaneous fission rate of nuclear reactor-bred plutonium was too high for use in a gun-type design due to the high concentration of the isotope plutonium-240. Early decisions In 1942, prior to the United States Army taking over control of wartime atomic research in what became known as the Manhattan Project, Robert Oppenheimer held conferences in Chicago in June and Berkeley, California in July, at which physicists discussed nuclear bomb design issues. A gun-type design was chosen, in which two sub-critical masses of plutonium would be brought together by firing a "bullet" into a "target". The idea of an implosion-type nuclear weapon was suggested by Richard Tolman, but it attracted scant consideration, being far more complex. Oppenheimer reviewed his options in early 1943 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Serber
Robert Serber (March 14, 1909 – June 1, 1997) was an American physicist who participated in the Manhattan Project. Serber's lectures explaining the basic principles and goals of the project were printed and supplied to all incoming scientific staff, and became known as '' The Los Alamos Primer''. The ''New York Times'' called him “the intellectual midwife at the birth of the atomic bomb.” Early life and education He was born in Philadelphia, the eldest son of Rose (Frankel) and David Serber. His family was Jewish. His mother died in 1922 and his father married her cousin Frances Leof in 1928. Robert Serber earned his BS in engineering physics from Lehigh University in 1930 and earned his PhD in physics from the University of Wisconsin–Madison with John Van Vleck in 1934. He married Charlotte Leof (26 Jul 1911 – 1967), the daughter of his stepmother's uncle, in 1933. Shortly before receiving his doctorate, Serber was selected for a National Research Council postdoctor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lockheed P2V Neptune
The Lockheed P-2 Neptune (designated P2V by the United States Navy prior to September 1962) is a Maritime patrol aircraft, maritime patrol and anti-submarine warfare (ASW) aircraft. It was developed for the US Navy by Lockheed Corporation, Lockheed to replace the Lockheed Ventura, Lockheed PV-1 Ventura and PV-2 Harpoon, and was replaced in turn by the Lockheed P-3 Orion. Designed as a land-based aircraft, the Neptune never made a carrier landing, but a small number were converted and deployed as carrier-launched, stop-gap nuclear bombers that would have to land on shore or ditch. The type was successful in export, and saw service with several armed forces. Design and development Development of a new land-based patrol bomber began early in World War II, with design work starting at Lockheed's Vega Aircraft Corporation, Vega subsidiary as a private venture on 6 December 1941.Scutts ''Air International'' January 1995, pp. 42–43. At first, the new design was considered a low pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bureau Of Ordnance
The Bureau of Ordnance (BuOrd) was a United States Navy organization, which was responsible for the procurement, storage, and deployment of all naval weapons, between the years 1862 and 1959. History Congress established the Bureau in the Department of the Navy by an act of July 5, 1862 (12 Stat. 510), which transferred the hydrographic functions of the Navy's Bureau of Ordnance and Hydrography (1842–1862) to the newly established Bureau of Navigation. During the early 20th century, BuOrd became involved in the development of aerial weapons. This often led to friction with the Bureau of Aeronautics (BuAer), which had responsibility for the development of Naval aircraft. BuAer's work on "pilotless aircraft," or drones, conflicted with BuOrd's development of guided missiles. After World War II, the Navy examined ways to improve coordination between the two bureaus; ultimately, the decision was made to merge the two organizations into a new bureau, to be known as the Bureau of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandia Base
Sandia Base was the principal nuclear weapons installation of the United States Department of Defense from 1946 to 1971. It was located on the southeastern edge of Albuquerque, New Mexico. For 25 years, the top-secret Sandia Base and its subsidiary installation, Manzano Base, carried on the atomic weapons research, development, design, testing, and training commenced by the Manhattan Project during World War II. Fabrication, assembly, and storage of nuclear weapons was also done at Sandia Base. The base played a key role in the United States nuclear deterrence capability during the Cold War. In 1971 it was merged into Kirtland Air Force Base. Geography Sandia Base was located at about 35° 02' 25" N, 106° 32' 59" W at an elevation above sea level. It was in the southeast quadrant of Albuquerque, bounded roughly by Louisiana Boulevard SE and Kirtland Air Force Base on the west, and Eubank Avenue SE and the Sandia Mountains on the east, and Isleta Pueblo lands on the south. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wigner Effect
The Wigner effect (named for its discoverer, Eugene Wigner), also known as the discomposition effect or Wigner's disease, is the displacement of atoms in a solid caused by neutron radiation. Any solid can display the Wigner effect. The effect is of most concern in neutron moderators, such as graphite, intended to reduce the speed of Neutron temperature#Fast, fast neutrons, thereby turning them into Neutron temperature, thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235. Explanation To create the Wigner effect, neutrons that collide with the atoms in a crystal structure must have enough energy to displace them from the lattice. This amount (threshold displacement energy) is approximately 25 Electronvolt, eV. A neutron's energy can vary widely, but it is not uncommon to have energies up to and exceeding 10 MeV (10,000,000 eV) in the centre of a nuclear reactor. A neutron with a significant amount of energy will create a Collision cascade, displa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hanford Site
The Hanford Site is a decommissioned nuclear production complex operated by the United States federal government on the Columbia River in Benton County in the U.S. state of Washington. The site has been known by many names, including SiteW and the Hanford Nuclear Reservation. Established in 1943 as part of the Manhattan Project, the site was home to the Hanford Engineer Works and B Reactor, the first full-scale plutonium production reactor in the world. Plutonium manufactured at the site was used in the first atomic bomb, which was tested in the Trinity nuclear test, and in the Fat Man bomb that was used in the bombing of Nagasaki. During the Cold War, the project expanded to include nine nuclear reactors and five large plutonium processing complexes, which produced plutonium for most of the more than sixty thousand weapons built for the U.S. nuclear arsenal. Nuclear technology developed rapidly during this period, and Hanford scientists produced major technological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highly Enriched Uranium
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U with 99.2739–99.2752% natural abundance), uranium-235 (235U, 0.7198–0.7202%), and uranium-234 (234U, 0.0050–0.0059%). 235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons. Enriched uranium is a critical component for both civil nuclear power generation and military nuclear weapons. The International Atomic Energy Agency attempts to monitor and control enriched uranium supplies and processes in its efforts to ensure nuclear power generation safety and curb nuclear weapons proliferation. There are about 2,000 tonnes of highly enriched uranium in the world, produced mostly for nuclear power, nuclear weapons, naval propulsion, and smaller quantities for research reactors. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid. One of its first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. It was also used to replace gunpowder as a low-order explosive in mining and other applications. In the form of collodion it was also a critical component in an early photographic emulsion, the use of which revolutionized photography in the 1860s. Production The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. The quality of the cellulose is important. Hemicellulose, lignin, pentosans, and mineral salts give inferior nitrocelluloses. In precise chemical terms, nitrocellulose is not a nitro compound, but a nitrate ester. The glucose repeat unit (anhydroglucose) within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plutonium-239
Plutonium-239 (239Pu or Pu-239) is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 is also used for that purpose. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in thermal spectrum nuclear reactors, along with uranium-235 and uranium-233. Plutonium-239 has a half-life of 24,110 years. Nuclear properties The nuclear properties of plutonium-239, as well as the ability to produce large amounts of nearly pure 239Pu more cheaply than highly enriched weapons-grade uranium-235, led to its use in nuclear weapons and nuclear power plants. The fissioning of an atom of uranium-235 in the reactor of a nuclear power plant produces two to three neutrons, and these neutrons can be absorbed by uranium-238 to produce plutonium-239 and other isotopes. Plutonium-239 can also absorb neutrons and fission along with the uranium-235 in a reactor. Of all the common nuclear fuels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
