1.
Mushroom cloud
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A mushroom cloud is a distinctive pyrocumulus mushroom-shaped cloud of debris/smoke and usually condensed water vapor resulting from a large explosion. The effect is most commonly associated with an explosion. They can be caused by conventional weapons, like vacuum bombs, including the ATBIP. 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 stabilization altitude depends strongly on the profiles of the temperature, dew point, although the term appears to have been coined at the start of the 1950s, mushroom clouds generated by explosions were being described centuries before the atomic era. The Times published a report on 1 October 1937 of a Japanese attack on Shanghai in China which generated a great mushroom of smoke, the 1917 Halifax Explosion also produced one. During World War II, descriptions of mushroom clouds were relatively common, the atomic bomb cloud over Nagasaki, Japan was described in The Times of London of 13 August 1945 as a huge mushroom of smoke and dust. He wrote of the bomb producing a pillar of purple fire, later in 1946, the Operation Crossroads nuclear bomb tests were described as having a cauliflower cloud, but a reporter present also spoke of the mushroom, now the common symbol of the atomic age. Mushrooms have traditionally been associated both with life and death, food and poison, making them a powerful symbolic connection than, say. Mushroom clouds are formed by many sorts of large explosions under earths gravity, without gravity, the explosives by-product gases would remain spherical. Nuclear weapons are usually detonated above the ground, to maximize the effect of their spherically expanding fireball, immediately after the detonation, the fireball begins to rise into the air, acting on the same principle as a hot-air balloon. One way to analyze the motion, once the hot gas has cleared the ground sufficiently, is as a spherical cap bubble, as this gives agreement between the rate of rise and observed diameter. When the detonation altitude is low enough, these afterwinds will draw in dirt, Nuclear detonations produced high above the ground might not create mushroom clouds with a stem. Detonations underwater but near the surface produce a pillar of water, which, in collapsing, forms a cauliflower-like shape, underground detonations at low depth produce a mushroom cloud and a base surge, two different distinct clouds. The amount of radiation vented into the atmosphere decreases rapidly with increasing detonation depth, with surface and near-surface air bursts, the amount of debris lofted into the air decreases rapidly with increasing burst altitude. At burst altitudes of approximately 7 meters/kiloton^0.33, a crater is not formed, the fallout-reducing height, above which the primary radioactive particles consist mainly of the fine fireball condensation, is approximately 55 meters/kiloton^0.4. However, even at these burst altitudes, fallout may be formed by a number of mechanisms, the distribution of radiation in the mushroom cloud varies with yield of the explosion, type of weapon, fusion/fission ratio, burst altitude, terrain type, and weather. In general, lower-yield explosions have about 90% of their radioactivity in the mushroom head, in contrast, megaton-range explosions tend to have most of their radioactivity in the lower third of the mushroom cloud
2.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
3.
Operation Castle
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Operation Castle was a United States series of high-yield nuclear tests by Joint Task Force 7 at Bikini Atoll beginning in March 1954. It followed Operation Upshot–Knothole and preceded Operation Teapot, Operation Castle was considered by government officials to be a success as it proved the feasibility of deployable dry fuel designs for thermonuclear weapons. There were technical difficulties with some of the tests, one device had a much lower than predicted. Public reaction to the tests and an awareness of the effects of nuclear fallout has been attributed as being part of the motivation for the Partial Test Ban Treaty of 1963. Bikini Atoll had previously hosted nuclear testing in 1946 as part of Operation Crossroads where the fourth and fifth atomic weapons were detonated in Bikini Lagoon. Since then, US nuclear weapons testing had moved to Enewetok Atoll to take advantage of larger islands. Both Atolls were part of the US Pacific Proving Grounds, the extremely high yields of the Castle weapons caused concern within the AEC that potential damage to the limited infrastructure already established at Enewetak would delay other operations. The Ivy Mike test was the worlds first hydrogen bomb, producing a full-scale thermonuclear or fusion explosion, the Ivy Mike device used liquid deuterium, an isotope of hydrogen, making it a wet bomb. The complex dewar mechanisms needed to store the liquid deuterium at cryogenic temperatures made the three stories tall and 82 tons in total weight, far from being a deliverable weapon. The final result incorporated lithium deuteride as the fuel in the Teller-Ulam design, vastly reducing size and weight. Operation Castle was charted to test four dry fuel designs, two wet bombs, and one smaller device, approval for Operation Castle was communicated to JTF-7 by Major General Kenneth D. Nichols, General Manager of the AEC, on 21 January 1954. Operation Castle was organized into seven experiments, all but one of which were to place at Bikini Atoll. Below is the original test schedule, Operation Castle was intended to test lithium deuteride as a thermonuclear fusion fuel. A solid at room temperature, LiD, if it worked, the same Teller-Ulam principle would be used as in the Ivy Mike Sausage device, but the fusion reactions were different. Ivy Mike fused deuterium with deuterium, but the LiD devices would fuse deuterium with tritium, the tritium was produced during the explosion by irradiating the lithium with fast neutrons. Bravo Yankee and Union used lithium enriched in the Li-6 isotope while Romeo, the first one started production in the fall of 1953. As a hedge, development of liquid deuterium weapons continued in parallel, the Ramrod and Jughead devices were liquid fuel designs greatly reduced in size and weight from their Ivy Mike Sausage predecessor. The Jughead device was ultimately weaponized and saw limited fielding in the inventory until the dry fuel weapons were common, Nectar was not a fusion weapon in the same sense as the rest of the Castle series
4.
Bikini Atoll
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Bikini Atoll is an atoll in the Marshall Islands which consists of 23 islands totaling 3.4 square miles surrounding a deep 229. 4-square-mile central lagoon. It is at the end of the Ralik Chain, approximately 87 kilometres northwest of Ailinginae Atoll and 850 kilometres northwest of Majuro. Within Bikini Atoll, Bikini, Eneu, Nam, and Enidrik islands comprise just over 70% of the land area, Bikini and Eneu are the only islands of the atoll that hosted a permanent population. Bikini Island is the northeastern most and largest islet, before World War II, the atoll was known by its German name, Eschscholtz Atoll. The islands English name is derived from the German colonial name Bikini given to the atoll when it was part of German New Guinea. The German name is transliterated from the Marshallese name for the island, Pikinni, Pik meaning surface and Ni meaning coconut, before the advent of Western influence, the Bikini islanders sustenance-based lifestyle was based on cultivating native plants and eating shellfish and fish. They were skilled builders and navigators, sailing the two-hulled proa to and from islets around the Bikini. The islanders were relatively isolated and had developed a society bound by close extended family association and tradition. Every lagoon was led by a king and queen and a following of chieftains, some of the leaders maintained Asian-style bungalows and maintained servants, including secretaries, maids, and valets. The islanders worked the plantations under the watchful eye of the Japanese. Chiefs could retain as much as $20,000 per year, the Marshall islanders were formerly aggressive, but the influence of the mission churches eliminated most conflict. They took pride in extending hospitality to one another, even distant relatives, the men wore a fringe skirt of native materials about 25 to 30 inches long. Women traditionally wore two mats about a square each, made by weaving pandanus and hibiscus leaves together. The Christian missionaries who began arriving in the late 19th century influenced the islanders notions of modesty, in 1919, a visitor reported that Marshall Islands women are perfect models of prudery. Not one would think of exposing her ankles, women in the Marshall Islands today are still very modest. They believe that a womans thighs and shoulders should be covered, women generally wear cotton muʻumuʻus or similar clothing that covers most of the body. Personal health is never discussed except within the family, and women are especially private about female-related health issues, Marshall island women swim in muʻumuʻus which are made of a fine polyester that quickly dries. In the capital of Majuro, revealing cocktail dresses are inappropriate for both islanders and guests, with the increasing influence of Western media, the younger generation may wear shorts, though the older generation equates shorts with loose morals
5.
Nuclear weapons testing
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Nuclear weapons tests are experiments carried out to determine the effectiveness, yield, and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that developed nuclear weapons tested them, the first nuclear device was detonated as a test by the United States at the Trinity site on July 16,1945, with a yield approximately equivalent to 20 kilotons of TNT. The first thermonuclear weapon technology test of engineer device, codenamed Mike, was tested at the Enewetak atoll in the Marshall Islands on November 1,1952, also by the United States. The largest nuclear weapon ever tested was the Tsar Bomba of the Soviet Union at Novaya Zemlya on October 30,1961, with the largest yield ever seen, the treaty permitted underground nuclear testing. France continued atmospheric testing until 1974, and China continued until 1980, underground tests in the United States continued until 1991, the Soviet Union until 1990, the United Kingdom until 1991, and both China and France until 1996. Non-signatories India and Pakistan last tested nuclear weapons in 1998, North Korea conducted nuclear tests in 2006,2009,2013, and 2016. The most recent confirmed nuclear test occurred in September 2016 in North Korea, Nuclear weapons tests have historically been divided into four categories reflecting the medium or location of the test. Atmospheric testing designates explosions that take place in the atmosphere, Nuclear explosions close enough to the ground to draw dirt and debris into their mushroom cloud can generate large amounts of nuclear fallout due to irradiation of the debris. This definition of atmospheric is used in the Limited Test Ban Treaty, underground testing refers to nuclear tests conducted under the surface of the earth, at varying depths. True underground tests are intended to be contained and emit a negligible amount of fallout. Unfortunately these nuclear tests do occasionally vent to the surface, producing from nearly none to considerable amounts of debris as a consequence. In 1976, the United States and the USSR agreed to limit the maximum yield of underground tests to 150 kt with the Threshold Test Ban Treaty. Underground testing also falls into two categories, tunnel tests in generally horizontal tunnel drifts, and shaft tests in vertically drilled holes. Exoatmospheric testing refers to tests conducted above the atmosphere. The test devices are lifted on rockets, underwater testing results from nuclear devices being detonated underwater, usually moored to a ship or a barge. Tests of this nature have usually been conducted to evaluate the effects of weapons against naval vessels. Another way to nuclear tests are by the number of explosions that constitute the test.1 second. The USSR has exploded up to eight devices in a single salvo test, Pakistans second, almost all lists in the literature are lists of tests, in the lists in Wikipedia, the lists are of explosions
6.
TNT equivalent
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TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The ton of TNT is a unit of energy defined by convention to be 4.184 gigajoules. The convention intends to compare the destructiveness of an event with that of conventional explosives, the kiloton is a unit of energy equal to 4.184 terajoules. The megaton is a unit of equal to 4.184 petajoules. The kiloton and megaton of TNT have traditionally used to describe the energy output. The TNT equivalent appears in various nuclear weapon control treaties, and has used to characterize the energy released in such other highly destructive events as an asteroid impact. A gram of TNT releases 2673–6702 J upon explosion, the energy liberated by one gram of TNT was arbitrarily defined as a matter of convention to be 4184 J, which is exactly one kilocalorie. The measured, pure heat output of a gram of TNT is only 2724 J, alternative TNT equivalency can be calculated as a function of when in the detonation the value is measured and which property is being compared. A kiloton of TNT can be visualized as a cube of TNT8.46 metres on a side, the RE factor is the relative mass of TNT to which an explosive is equivalent, the greater the RE, the more powerful the explosive. This enables engineers to determine the proper masses of different explosives when applying blasting formulas developed specifically for TNT. For example, if a timber-cutting formula calls for a charge of 1 kg of TNT, then based on octanitrocubanes RE factor of 2.38, using PETN, engineers would need 1. 0/1.66 kg to obtain the same effects as 1 kg of TNT. With ANFO or ammonium nitrate, they would require 1. 0/0.74 kg or 1. 0/0.42 kg, *, TBX or EBX, in a small, confined space, may have over twice the power of destruction. The total power of aluminized mixtures strictly depends on the condition of explosions, guide for the Use of the International System of Units. National Institute of Standards and Technology, nuclear Weapons FAQ Part 1.3 Rhodes, Richard. The Making of the Atomic Bomb, cooper, Paul W. Explosives Engineering, New York, Wiley-VCH, ISBN 0-471-18636-8 HQ Department of the Army, Field Manual 5-25, Explosives and Demolitions, Washington, D. C. Pentagon Publishing, pp. 83–84, ISBN 0-9759009-5-1 Explosives - Compositions, Alexandria, VA, thermobaric Explosives, Advanced Energetic Materials,2004. THE NATIONAL ACADEMIES PRESS, nap. edu, retrieved September 2004
7.
Joule
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The joule, symbol J, is a derived unit of energy in the International System of Units. It is equal to the transferred to an object when a force of one newton acts on that object in the direction of its motion through a distance of one metre. It is also the energy dissipated as heat when a current of one ampere passes through a resistance of one ohm for one second. It is named after the English physicist James Prescott Joule, one joule can also be defined as, The work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one coulomb volt. This relationship can be used to define the volt, the work required to produce one watt of power for one second, or one watt second. This relationship can be used to define the watt and this SI unit is named after James Prescott Joule. As with every International System of Units unit named for a person, note that degree Celsius conforms to this rule because the d is lowercase. — Based on The International System of Units, section 5.2. The CGPM has given the unit of energy the name Joule, the use of newton metres for torque and joules for energy is helpful to avoid misunderstandings and miscommunications. The distinction may be also in the fact that energy is a scalar – the dot product of a vector force. By contrast, torque is a vector – the cross product of a distance vector, torque and energy are related to one another by the equation E = τ θ, where E is energy, τ is torque, and θ is the angle swept. Since radians are dimensionless, it follows that torque and energy have the same dimensions, one joule in everyday life represents approximately, The energy required to lift a medium-size tomato 1 m vertically from the surface of the Earth. The energy released when that same tomato falls back down to the ground, the energy required to accelerate a 1 kg mass at 1 m·s−2 through a 1 m distance in space. The heat required to raise the temperature of 1 g of water by 0.24 °C, the typical energy released as heat by a person at rest every 1/60 s. The kinetic energy of a 50 kg human moving very slowly, the kinetic energy of a 56 g tennis ball moving at 6 m/s. The kinetic energy of an object with mass 1 kg moving at √2 ≈1.4 m/s, the amount of electricity required to light a 1 W LED for 1 s. Since the joule is also a watt-second and the unit for electricity sales to homes is the kW·h. For additional examples, see, Orders of magnitude The zeptojoule is equal to one sextillionth of one joule,160 zeptojoules is equivalent to one electronvolt. The nanojoule is equal to one billionth of one joule, one nanojoule is about 1/160 of the kinetic energy of a flying mosquito
8.
Castle Romeo
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Castle Romeo was the code name given to one of the tests in the Operation Castle series of American nuclear tests. It was the first test of the TX-17 thermonuclear weapon, the first deployed thermonuclear bomb. It was detonated on March 27,1954, after several delays at Bikini Atoll of the Marshall Islands and it was the first such barge-based test, a necessity that had come about because the powerful thermonuclear devices completely obliterated the small islands following detonation. Like the Bravo test, it ran away and produced far more than its predicted yield, and for the same reason—an unexpected participation of the common lithium-7 isotope in fusion reactions. Although it had predicted to produce a yield of 4 megatons with a range of 1.5 to 7 megatons, it actually produced a yield of 11 megatons. Like the Ivy Mike and Castle Bravo tests, a percentage of the yield was produced by fast fission of the natural uranium tamper,7 megatons of the yield were from this source. This became the first air-droppable thermonuclear device, the EC-17, of which only 5 were made and this evolved into the Mk 17 of which 200 were made. Both of these were huge devices, weighing 39,000 and 42,000 pounds respectively, as a result, they were only capable of being carried by the B-36. They were also some of the largest yield devices deployed by Strategic Air Command—the EC-17 giving around 10 Mt and they were all out of service by August 1957. One prominent usage is as the backdrop for heavy metal band Megadeths greatest hits compilation Greatest Hits, the image of Castle Romeo was also used on the cover of the New York hardcore music pioneers Cro-Mags debut album The Age of Quarrel. It is also featured on the screen of Team17s turn-based artillery game Worms Armageddon. The Castle Romeo photos are sometimes confused with that of Castle Bravo, the two nuclear blasts looked very similar, and they were both conducted in the same location
9.
Marshall Islands
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The Marshall Islands, officially the Republic of the Marshall Islands, is an island country located near the equator in the Pacific Ocean, slightly west of the International Date Line. Geographically, the country is part of the island group of Micronesia. The countrys population of 53,158 people is spread out over 29 coral atolls, comprising 1,156 individual islands and islets. The islands share maritime boundaries with the Federated States of Micronesia to the west, Wake Island to the north, Kiribati to the south-east, about 27,797 of the islanders live on Majuro, which contains the capital. Micronesian colonists gradually settled the Marshall Islands during the 2nd millennium BC, Islands in the archipelago were first explored by Europeans in the 1520s, with Spanish explorer Alonso de Salazar sighting an atoll in August 1526. Other expeditions by Spanish and English ships followed, the islands derive their name from British explorer John Marshall, who visited in 1788. The islands were known by the inhabitants as jolet jen Anij. The European powers recognized Spanish sovereignty over the islands in 1874 and they had been part of the Spanish East Indies formally since 1528. Later, Spain sold the islands to the German Empire in 1884, in World War I the Empire of Japan occupied the Marshall Islands, which in 1919 the League of Nations combined with other former German territories to form the South Pacific Mandate. In World War II, the United States conquered the islands in the Gilbert, along with other Pacific Islands, the Marshall Islands were then consolidated into the Trust Territory of the Pacific Islands governed by the US. Self-government was achieved in 1979, and full sovereignty in 1986, Marshall Islands has been a United Nations member state since 1991. The country uses the United States dollar as its currency, the majority of the citizens of the Marshall Islands are of Marshallese descent, though there are small numbers of immigrants from the United States, China, Philippines, and other Pacific islands. The two official languages are Marshallese, which is a member of the Malayo-Polynesian languages, and English, micronesians settled the Marshall Islands in the 2nd millennium BC, but there are no historical or oral records of that period. Over time, the Marshall Island people learned to navigate over long distances by canoe using traditional stick charts. Spanish explorer Alonso de Salazar was the first European to see the islands in 1526, commanding the ship Santa Maria de la Victoria, on August 21, he sighted an island at 14°N that he named San Bartolome. On September 21,1529, Álvaro de Saavedra Cerón commanded the Spanish ship Florida and he stood off a group of islands from which local inhabitants hurled stones at his ship. These islands, which he named Los Pintados, may have been Ujelang, on October 1, he found another group of islands where he went ashore for eight days, exchanged gifts with the local inhabitants and took on water. These islands, which he named Los Jardines, may have been Enewetak or Bikini Atoll
10.
Nuclear weapon
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A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from small amounts of matter. The first test of a bomb released the same amount of energy as approximately 20,000 tons of TNT. The first thermonuclear bomb test released the same amount of energy as approximately 10 million tons of TNT, a thermonuclear weapon weighing little more than 2,400 pounds can produce an explosive force comparable to the detonation of more than 1.2 million tons of TNT. A nuclear device no larger than traditional bombs can devastate a city by blast, fire. Nuclear weapons are considered weapons of destruction, and their use. Nuclear weapons have been used twice in nuclear warfare, both times by the United States against Japan near the end of World War II, the bombings resulted in the deaths of approximately 200,000 civilians and military personnel from acute injuries sustained from the explosions. The ethics of the bombings and their role in Japans surrender remain the subject of scholarly, since the atomic bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated on over two thousand occasions for the purposes of testing and demonstration. Only a few nations possess such weapons or are suspected of seeking them, israel is also believed to possess nuclear weapons, though in a policy of deliberate ambiguity, it does not acknowledge having them. Germany, Italy, Turkey, Belgium and the Netherlands are nuclear weapons sharing states, south Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons. Modernisation of weapons continues to occur, all existing nuclear weapons derive some of their explosive energy from nuclear fission reactions. Weapons whose explosive output is exclusively from fission reactions are commonly referred to as bombs or atom bombs. This has long noted as something of a misnomer, as their energy comes from the nucleus of the atom. The latter approach is considered more sophisticated than the former and only the approach can be used if the fissile material is plutonium. A major challenge in all nuclear weapon designs is to ensure that a significant fraction of the fuel is consumed before the weapon destroys itself. The amount of energy released by fission bombs can range from the equivalent of just under a ton to upwards of 500,000 tons of TNT, all fission reactions necessarily generate fission products, the radioactive remains of the atomic nuclei split by the fission reactions. Many fission products are highly radioactive or moderately radioactive. Fission products are the radioactive component of nuclear fallout
11.
Lithium deuteride
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Lithium hydride is an inorganic compound with the formula LiH. This alkali metal hydride is a solid, although commercial samples are grey. With a molecular mass of less than 8, it is the lightest ionic compound. The dielectric constant of LiH decreases from 13.0 to 3.6, LiH is a soft material with a Mohs hardness of 3.5. Its compressive creep rapidly increases from < 1% at 350 °C to > 100% at 475 °C meaning that LiH cant provide mechanical support when heated, the linear thermal expansion coefficient is 4. 2×10−5/°C at room temperature. LiH is produced by treating lithium metal with hydrogen gas,2 Li + H2 →2 LiH This reaction is rapid at temperatures above 600 °C. Addition of 0. 001–0. 003% carbon, or/and increasing temperature or/and pressure, however, the reaction proceeds at temperatures as low as 29 °C. The yield is 60% at 99 °C and 85% at 125 °C, Chemical reactions yield LiH in the form of lumped powder, which can be compressed into pellets without a binder. More complex shapes can be produced by casting from the melt, large single crystals can be then grown from molten LiH powder in hydrogen atmosphere by the Bridgman–Stockbarger technique. They often have bluish color owing to the presence of colloidal Li and this color can be removed by post-growth annealing at lower temperatures and lower thermal gradients. Major impurities in these crystals are Na, O, Mg, Fe, bulk cold-pressed LiH parts can be easily machined using standard techniques and tools to micrometer precision. However, cast LiH is brittle and easily cracks during processing, LiH powder reacts rapidly with air of low humidity, forming LiOH, Li 2O and Li 2CO3. In moist air the powder ignites spontaneously, forming a mixture of products including some nitrogenous compounds, the lump material reacts with humid air forming a superficial coating which is a viscous fluid. This inhibits further reaction, although the appearance of a film of tarnish is quite evident, little or no nitride is formed on exposure to humid air. The lump material, contained in a dish, may be heated in air to slightly below 200 °C, without igniting. The surface condition of LiH, presence of oxides on the metal dish, dry oxygen does not react with crystalline LiH unless heated strongly, when an almost explosive combustion occurs. This is true of all the binary saline hydrides, LiH pellets slowly expand in moist air forming LiOH, however, the expansion rate is below 10% within 24 hours in a pressure of 2 mm of water vapor. If moist air contains carbon dioxide then the product is lithium carbonate, LiH reacts with ammonia, slowly at room temperature, but the reaction accelerates significantly above 300 °C
12.
Thermonuclear weapon
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A thermonuclear weapon is a nuclear weapon that uses the energy from a primary nuclear fission reaction to compress and ignite a secondary nuclear fusion reaction. The result is greatly increased power when compared to single-stage fission weapons. It is colloquially referred to as a bomb or an H-bomb because it employs the fusion of isotopes of hydrogen. The first full scale thermonuclear test was carried out by the United States in 1952, similar devices were developed by the Soviet Union, United Kingdom, China, and France. The radiation implosion mechanism is an engine that exploits the temperature difference between the secondary stages hot, surrounding radiation channel and its relatively cool interior. This temperature difference is maintained by a massive heat barrier called the pusher. If made of uranium, as is almost always the case, it can capture neutrons produced by the reaction and undergo fission itself. In many Teller–Ulam weapons, fission of the pusher dominates the explosion, detailed knowledge of fission and fusion weapons is classified to some degree in virtually every industrialized nation. Born secret is rarely invoked for cases of private speculation, in a small number of prior cases, the U. S. government has attempted to censor weapons information in the public press, with limited success. According to the New York Times, physicist Kenneth Ford defied government orders to remove classified information from his new book, Building the H Bomb, the state of public knowledge about the Teller–Ulam design has been mostly shaped from a few specific incidents outlined in a section below. At a bare minimum, this implies a primary section consists of an implosion-type fission bomb. The energy released by the primary compresses the secondary through a process called radiation implosion, at which point it is heated, surrounding the other components is a hohlraum or radiation case, a container that traps the first stage or primarys energy inside temporarily. The outside of this case, which is also normally the outside casing of the bomb, is the only direct visual evidence publicly available of any thermonuclear bomb components configuration. Numerous photographs of various thermonuclear bomb exteriors have been declassified, generally, a research program with the capacity to create a thermonuclear bomb has already mastered the ability to engineer boosted fission. The secondary is usually shown as a column of fusion fuel, around the column is first a pusher-tamper, a heavy layer of uranium-238 or lead that serves to help compress the fusion fuel. Inside this is the fuel itself, usually a form of lithium deuteride. This dry fuel, when bombarded by neutrons, produces tritium, inside the layer of fuel is the spark plug, a hollow column of fissile material that, when compressed, can itself undergo nuclear fission. The tertiary, if one is present, would be set below the secondary, separating the secondary from the primary is the interstage
13.
Nuclear weapon yield
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An explosive yield of one terajoule is 0.239 kt of TNT. 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 has been estimated to six megatons of TNT per metric ton of bomb mass. Yields of 5.2 megatons/ton and higher have been reported for large weapons constructed for use in the early 1960s. Most artificial non-nuclear explosions are considerably smaller than even what are considered to be very small nuclear weapons, the yield-to-weight ratio is the amount of weapon yield compared to the mass of the weapon. According to nuclear-weapons designer Ted Taylor, the practical maximum yield-to-weight ratio for fusion weapons is about 6 megatons of TNT per metric ton. The Taylor limit is not derived from first principles, and weapons with yields as high as 9.5 megatons per metric ton have been designed and built. The 25 Mt yield option reported for the B41 would give it a ratio of 5.1 megatons of TNT per metric ton. This results in the B41 still retaining the record for the highest Yield-to-weight weapon ever designed, in 1963 DOE declassified statements that the U. S. had the technological capability of deploying a 35 Mt warhead on the Titan II, or a 50-60 Mt gravity bomb on B-52s. Neither weapon was pursued, but either would require yield-to-weight ratios superior to a 25 Mt Mk-41, for current smaller US weapons, yield is 600 to 2200 kilotons of TNT per metric ton. By comparison, for the very small devices such as the Davy Crockett it was 0.4 to 40 kilotons of TNT per metric ton. For historical comparison, for Little Boy the yield was only 4 kilotons of TNT per metric ton, and for the largest Tsar Bomba, the yield was 2 megatons of TNT per metric ton. The largest pure-fission bomb ever constructed Ivy King had a 500 kiloton yield, however, there is no known upper yield limit for a fusion bomb. For example, the Mk-36 bomb as built had a ratio of 1.25 megatons of TNT per metric ton. Delivery size limits can be estimated to ascertain limits to delivery of high yield weapons. If the full 250 metric ton payload of the Antonov An-225 aircraft could be used, likewise, the maximum limit of a missile-delivered weapon is determined by the missile gross payload capacity. The large Russian SS-18 ICBM has a capacity of 7,200 kg. A Saturn V-scale missile could deliver over 120 tons, giving a maximum yield of about 700 megatons. The following list is of nuclear explosions
14.
Nuclear fallout
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It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes, but such dust can also originate from a damaged nuclear plant. Fallout may get entrained with the products of a pyrocumulus cloud and this radioactive dust, usually consisting of fission products mixed with bystanding atoms that are neutron activated by exposure, is a highly dangerous kind of radioactive contamination. An air burst can eventually produce worldwide fallout, a ground burst can produce possibly much more severe, local fallout. These particles may be drawn up into the stratosphere, particularly if the explosive yield exceeds 10 kt. Initially little was known about the dispersion of nuclear fallout on a global scale, the AEC assumed that fallout would be dispersed evenly across the globe by atmospheric winds and gradually settle to the Earths surface after weeks, months, and even years as worldwide fallout. This hazard is less pertinent than local fallout, which is of much greater immediate operational concern, in a land or water surface burst, heat vaporizes large amounts of earth or water, which is drawn up into the radioactive cloud. This material becomes radioactive when it condenses with fission products and other radiocontaminants that have become neutron-activated, the table below summarizes the abilities of common isotopes to form fallout. Some radiation taints large amounts of land and drinking water causing formal mutations throughout animal and human life. The larger particles spill out of the stem and cascade down the outside of the fireball in a downdraft even as the cloud rises, more than half the total bomb debris lands on the ground within about 24 hours as local fallout. Chemical properties of the elements in the control the rate at which they are deposited on the ground. Severe local fallout contamination can extend far beyond the blast and thermal effects, the ground track of fallout from an explosion depends on the weather from the time of detonation onwards. In stronger winds, fallout travels faster but takes the time to descend, so although it covers a larger path. Thus, the width of the pattern for any given dose rate is reduced where the downwind distance is increased by higher winds. The total amount of activity deposited up to any time is the same irrespective of the wind pattern. But thunderstorms can bring down activity as rain more rapidly than dry fallout, particularly if the cloud is low enough to be below, or mixed with. There are two considerations for the location of an explosion, height and surface composition. A nuclear weapon detonated in the air, called an air burst, in case of water surface bursts, the particles tend to be rather lighter and smaller, producing less local fallout but extending over a greater area. The particles contain mostly sea salts with some water, these can have a cloud seeding effect causing local rainout and areas of high local fallout
15.
Rongelap Atoll
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Rongelap Atoll /ˈrɒŋɡəlæp/ RONG-gə-lap or Namorik Atoll is a coral atoll of 61 islands in the Pacific Ocean, and forms a legislative district of the Ralik Chain of the Marshall Islands. Its total land area is 8 square miles and it encloses a lagoon with an area of 1,000 square miles. It is historically notable for its proximity to US hydrogen bomb tests in 1954. Twenty people remain from the more than 300 who lived prior to the test. The first sighting recorded by Europeans was by Spanish navigator Álvaro de Saavedra on 1 January 1528, together with Utirik, Ailinginae and Toke atolls, they were charted as Islas de los Reyes due to the proximity of Epiphany. Fourteen years later it was visited by the Spanish expedition of Ruy López de Villalobos, Rongelap Atoll was claimed by the Empire of Germany along with the rest of the Marshall Islands in 1884, and the Germans established a trading outpost. After World War I, the island came under the South Pacific Mandate of the Empire of Japan, following the end of World War II, Rongelap came under the control of the United States as part of the Trust Territory of the Pacific Islands. 1946, United States Navy evacuates Bikini Atoll Islanders prior to nuclear weapons tests, march 1,1954, United States detonates 15 megaton hydrogen bomb aware that fallout will reach Rongelap. March 3,1954, US evacuates Rongelap inhabitants to Kwajalein Atoll, Islanders have vomiting, diarrhea, skin burns and some later experience hair loss. 1955-1957, Internally displaced Rongelapese inhabitants repeatedly request permission from the US Government to return to their atoll,1957, Atomic Energy Commission declares Rongelap safe for re-habitation. US scientists note, The habitation of people on the island will afford most valuable ecological radiation data on human beings. 1958, Rates of Rongelap miscarriages and stillbirths twice the rate of unexposed women,1963, First thyroid tumors begin to appear. 1971, Independent Japanese medical team invited by Rongelap magistrate denied permissionto visit by US citing visa problems,1976, Report finds 69% of Rongelap children who were under 10 in 1954 have developed thyroid tumors. 1984, Marshall Islands senator Jeton Anjain requests evacuation assistance from Greenpeace,1985, Rainbow Warrior makes three trips to evacuate the Rongelap community to Majetto and Ebeye islands in Kwajalein Atoll. 1986, Nuclear test compensation approved, setting aside a $US150 million trust fund,1989, United States Department of Energy determines Rongelap safe for habitation. 1994, Independent scientific studyfinds that depending on restrictions,25 to 75% of Rongelap population would exceed the 100 mrem maximum annual exposure limit set. 2000, Marshall Islands government submits Change of Circumstances petition asking for more compensation than the $US150m. 2005, Bush Administration determines it has no responsibility to provide additional nuclear test compensation
16.
Utirik Atoll
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Utirik Atoll or Utrik Atoll is a coral atoll of 10 islands in the Pacific Ocean, and forms a legislative district of the Ratak Chain of the Marshall Islands. Its total land area is only 2.4 square kilometres and it is located approximately 47 kilometres east of Ujae Atoll. The population of Utirik Atoll is 409, it is one of the northernmost Marshall Islands with permanent habitation. The larger islets are, Utirik Aon Bikrak Pike Āllok Nalap Its first recorded sighting was by the Spanish navigator Álvaro de Saavedra on board of the ship Florida on 29 December 1527. Together with Rongelap, Ailinginae and Toke atolls, they were charted as Islas de los Reyes due to the proximity of Epiphany, Utirik Atoll was claimed by the Empire of Germany along with the rest of the Marshall Islands in 1884. After World War I, the island came under the South Pacific Mandate of the Empire of Japan, following the end of World War II, Utirik came under the control of the United States as part of the Trust Territory of the Pacific Islands. Utirik was one of four atolls affected by fallout from Castle Bravo. Research is still being done to ascertain the radiation levels, though many scientists agree that there is no effect from the radiation still present. The island has been part of the independent Republic of the Marshall Islands since 1986, also contaminated by Castle Bravo test, Rongelap Atoll, Ailinginae Atoll, Rongerik Atoll Marshall Islands site Entry at Oceandots. com at the Wayback Machine Video, Glimpse of Utrik Atoll
17.
Teller-Ulam design
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A thermonuclear weapon is a nuclear weapon that uses the energy from a primary nuclear fission reaction to compress and ignite a secondary nuclear fusion reaction. The result is greatly increased power when compared to single-stage fission weapons. It is colloquially referred to as a bomb or an H-bomb because it employs the fusion of isotopes of hydrogen. The first full scale thermonuclear test was carried out by the United States in 1952, similar devices were developed by the Soviet Union, United Kingdom, China, and France. The radiation implosion mechanism is an engine that exploits the temperature difference between the secondary stages hot, surrounding radiation channel and its relatively cool interior. This temperature difference is maintained by a massive heat barrier called the pusher. If made of uranium, as is almost always the case, it can capture neutrons produced by the reaction and undergo fission itself. In many Teller–Ulam weapons, fission of the pusher dominates the explosion, detailed knowledge of fission and fusion weapons is classified to some degree in virtually every industrialized nation. Born secret is rarely invoked for cases of private speculation, in a small number of prior cases, the U. S. government has attempted to censor weapons information in the public press, with limited success. According to the New York Times, physicist Kenneth Ford defied government orders to remove classified information from his new book, Building the H Bomb, the state of public knowledge about the Teller–Ulam design has been mostly shaped from a few specific incidents outlined in a section below. At a bare minimum, this implies a primary section consists of an implosion-type fission bomb. The energy released by the primary compresses the secondary through a process called radiation implosion, at which point it is heated, surrounding the other components is a hohlraum or radiation case, a container that traps the first stage or primarys energy inside temporarily. The outside of this case, which is also normally the outside casing of the bomb, is the only direct visual evidence publicly available of any thermonuclear bomb components configuration. Numerous photographs of various thermonuclear bomb exteriors have been declassified, generally, a research program with the capacity to create a thermonuclear bomb has already mastered the ability to engineer boosted fission. The secondary is usually shown as a column of fusion fuel, around the column is first a pusher-tamper, a heavy layer of uranium-238 or lead that serves to help compress the fusion fuel. Inside this is the fuel itself, usually a form of lithium deuteride. This dry fuel, when bombarded by neutrons, produces tritium, inside the layer of fuel is the spark plug, a hollow column of fissile material that, when compressed, can itself undergo nuclear fission. The tertiary, if one is present, would be set below the secondary, separating the secondary from the primary is the interstage
18.
Los Alamos National Laboratory
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Los Alamos National Laboratory is one of two laboratories in the United States in which classified work towards the design of nuclear weapons has been undertaken. LANL is a United States Department of Energy national laboratory, managed and operated by Los Alamos National Security, located in Los Alamos, the laboratory is one of the largest science and technology institutions in the world. It conducts multidisciplinary research in such as national security, space exploration, renewable energy, medicine, nanotechnology. General Leslie Groves wanted a central laboratory at a location for safety. It should be at least 200 miles from international boundaries and west of the Mississippi, major John Dudley suggested Oak City, Utah or Jemez Springs, New Mexico but both were rejected. Manhattan Project scientific director J. Robert Oppenheimer had spent much time in his youth in the New Mexico area, Dudley had rejected the school as not meeting Groves’ criteria, but as soon as Groves saw it he said in effect This is the place. Oppenheimer became the laboratorys first director, during the Manhattan Project, Los Alamos hosted thousands of employees, including many Nobel Prize-winning scientists. The location was a total secret and its only mailing address was a post office box, number 1663, in Santa Fe, New Mexico. Eventually two other post office boxes were used,180 and 1539, also in Santa Fe, though its contract with the University of California was initially intended to be temporary, the relationship was maintained long after the war. The work of the laboratory culminated in the creation of several devices, one of which was used in the first nuclear test near Alamogordo, New Mexico, codenamed Trinity. The other two were weapons, Little Boy and Fat Man, which were used in the attacks on Hiroshima, the Laboratory received the Army-Navy ‘E’ Award for Excellence in production on October 16,1945. Many of the original Los Alamos luminaries chose to leave the laboratory, in the years since the 1940s, Los Alamos was responsible for the development of the hydrogen bomb, and many other variants of nuclear weapons. In 1952, Lawrence Livermore National Laboratory was founded to act as Los Alamos competitor, Los Alamos and Livermore served as the primary classified laboratories in the U. S. national laboratory system, designing all the countrys nuclear arsenal. Additional work included basic research, particle accelerator development, health physics. Many nuclear tests were undertaken in the Marshall Islands and at the Nevada Test Site, during the late-1950s, a number of scientists including Dr. J. Robert Bob Beyster left Los Alamos to work for General Atomics in San Diego. Three major nuclear-related accidents have occurred at LANL, criticality accidents occurred in August 1945 and May 1946, and a third accident occurred during an annual physical inventory in December 1958. Several buildings associated with the Manhattan Project at Los Alamos were declared a National Historic Landmark in 1965, Los Alamos nuclear work is currently thought to relate primarily to computer simulations and stockpile stewardship. The development of the Dual-Axis Radiographic Hydrodynamic Test Facility will allow complex simulations of nuclear tests to take place without full explosive yields, the lab has made intense efforts for humanitarian causes through its scientific research in medicine
19.
Boosted fission weapon
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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, 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 an amount of energy to the process. This type of bomb was referred to by Edward Teller as Alarm Clock, the idea of boosting was originally developed between late 1947 and late 1949 at Los Alamos. This would eliminate the need for a pusher and uranium tamper and the explosives needed to push them. In a fission bomb, the fuel is assembled quickly by a uniform spherical implosion created with conventional explosives. In this state, many of the released by the fissioning of a nucleus will induce fission of other nuclei in the fuel mass, also releasing additional neutrons. This is due to several reasons, Their high velocity creates the opposite of time absorption, when these energetic neutrons strike a fissile nucleus, a much larger number of secondary neutrons are released by the fission. The fission cross section is both in absolute terms, and in proportion to the scattering and capture cross sections. The energy released by the fusion of the 5 g of fusion fuel itself is only 1. 73% of the released by the fission of 1,338 g of plutonium. Larger total yields and higher efficiency are possible, since the reaction can continue beyond the second generation after fusion boosting. The combination of reduced weight in relation to yield and immunity to radiation has ensured that most modern weapons are fusion-boosted. The fusion reaction rate typically becomes significant at 20 to 30 megakelvins and this temperature is reached at very low efficiencies, when less than 1% of the fissile material has fissioned. Elimination of this hazard is an important advantage in using boosting. It appears that every weapon now in the U. S. arsenal is a boosted design, according to one weapons designer, boosting is mainly responsible for the remarkable 100-fold increase in the efficiency of fission weapons since 1945. Early thermonuclear weapon such as the Joe-4, the Soviet Layer Cake. These weapons had a core surrounded by a layer of lithium-6 deuteride. Some designs had several layers of these materials
20.
Composition B
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Composition B, colloquially Comp B, is an explosive consisting of castable mixtures of RDX and TNT. It is used as the explosive filling in artillery projectiles, rockets, land mines, hand grenades. It was also used for the lenses in the first implosion-type nuclear weapons developed by the United States. The standard proportions of ingredients are 59. 5% RDX and 39. 4% TNT, most commonly it is described as 60/40 RDX/TNT with 1% wax added. M65 bombs from this period were responsible for the 1967 USS Forrestal fire, some NATO-approved munitions suppliers such as Mecar have continued to use Composition B in their products. Composition B is related to Cyclotol, which has a proportion of RDX. IMX-101 is slowly replacing Comp B in US military artillery shells, and IMX-104 in mortar rounds
21.
Greenhouse Item
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This test explosion was the first test of a boosted fission weapon. In this test deuterium-tritium gas was injected into the uranium core of a nuclear fission bomb. The extreme heat of the bomb produced thermonuclear fusion reactions within the D-T gas. This fusion reaction released a number of free neutrons, which greatly increased the efficiency of the nuclear fission reaction. The explosive yield of this bomb was 45.5 kilotons and this bomb was known as the Booster in its development stages, a name for the mechanism coined by Edward Teller in September 1947. Planning for it had begun in the late 1940s, according to the researcher Chuck Hansen, it was mentioned in official U. S. Atomic Energy Commission documents as early as 1947, the main problems in development were making modifications to the fission core in order to accept the gas correctly without reducing its own efficiency. The 1951 test was primarily to test the principles involved, and to gain research data. Even as late as 1954, no boosted weapon had entered into the stockpile. Chuck Hansen, Swords of Armageddon,1995, esp, the Item Shot in Volume III. The short film Nuclear Test Film - Operation Greenhouse is available for download at the Internet Archive Operation Greenhouse at nuclearweaponarchive. org
22.
Ivy Mike
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Ivy Mike was the codename given to the first test of a full-scale thermonuclear device, in which part of the explosive yield comes from nuclear fusion. It was detonated on November 1,1952 by the United States on the island of Elugelab in Enewetak Atoll, in the Pacific Ocean and it was the first full test of the Teller–Ulam design, a staged fusion device. The 82-ton Mike device was essentially a building that resembled a factory rather than a weapon and it has been reported that Soviet engineers derisively referred to Mike as a thermonuclear installation. At its center, a large cylindrical thermos flask or cryostat held the cryogenic deuterium fusion fuel. A regular fission bomb at one end was used to create the conditions needed to initiate the fusion reaction, the device was designed by Richard Garwin, a student of Enrico Fermi, on the suggestion of Edward Teller. The primary stage was a TX-5 boosted fission bomb in a separate space atop the assembly, the secondary fusion stage used liquid deuterium despite the difficulty of handling this material, because this fuel simplified the experiment, and made the results easier to analyze. Running down the center of the flask which held it, was a rod of plutonium to ignite the fusion reaction. Surrounding this assembly was a natural uranium tamper. The exterior of the tamper was lined with sheets of lead and polyethylene, the function of the X-rays was to compress the secondary, with tamper/pusher ablation, foam plasma pressure and radiation pressure. The outermost layer was a steel casing 10–12 inches thick, the entire assembly, nicknamed Sausage, measured 80 inches in diameter and 244 inches in height and weighed about 54 tons. The entire Mike device weighed 82 short tons, and was housed in a large building called a shot cab which was set up on the Pacific island of Elugelab. A9, 000-foot artificial causeway connected the islands of Elugelab, Teiter, Bogairikk, atop this causeway was an aluminium-sheathed plywood tube filled with helium ballonets. This allowed gamma and neutron radiation to pass uninhibited to an unmanned detection station housed in a bunker on Bogon, in total,9,350 military and 2,300 civilian personnel were involved in the Mike shot. A large cryogenics plant was installed on Parry Island, at the South end of the Enewetak atoll, to produce the liquid hydrogen, the test was carried out on 1 November 1952 at 07,15 local time. It produced a yield of 10.4 megatons of TNT, however, 77% of the final yield came from fast fission of the uranium tamper, which produced large amounts of radioactive fallout. The fireball created by the explosion had a radius of 2.9 to 3.3 km. This maximum is reached a number of seconds after the detonation, while still relatively close to the ground, the fireball had yet to reach its maximum dimensions and was thus approximately 5.2 km wide. The mushroom cloud rose to an altitude of 17 km in less than 90 seconds, one minute later it had reached 33 km, before stabilizing at 41 km with the top eventually spreading out to a diameter of 161 km with a stem 32 km wide
23.
Nuclear fusion
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In nuclear physics, nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles. The difference in mass between the products and reactants is manifested as the release of large amounts of energy and this difference in mass arises due to the difference in atomic binding energy between the atomic nuclei before and after the reaction. Fusion is the process that powers active or main sequence stars, the fusion process that produces a nucleus lighter than iron-56 or nickel-62 will generally yield a net energy release. These elements have the smallest mass per nucleon and the largest binding energy per nucleon, the opposite is true for the reverse process, nuclear fission. This means that the elements, such as hydrogen and helium, are in general more fusable, while the heavier elements. The extreme astrophysical event of a supernova can produce energy to fuse nuclei into elements heavier than iron. During the remainder of that decade the steps of the cycle of nuclear fusion in stars were worked out by Hans Bethe. Research into fusion for military purposes began in the early 1940s as part of the Manhattan Project, fusion was accomplished in 1951 with the Greenhouse Item nuclear test. Nuclear fusion on a scale in an explosion was first carried out on November 1,1952. Research into developing controlled thermonuclear fusion for civil purposes also began in earnest in the 1950s, the protons are positively charged and repel each other but they nonetheless stick together, demonstrating the existence of another force referred to as nuclear attraction. This force, called the nuclear force, overcomes electric repulsion at very close range. The effect of force is not observed outside the nucleus. The same force also pulls the nucleons together allowing ordinary matter to exist, light nuclei, are sufficiently small and proton-poor allowing the nuclear force to overcome the repulsive Coulomb force. This is because the nucleus is small that all nucleons feel the short-range attractive force at least as strongly as they feel the infinite-range Coulomb repulsion. Building up these nuclei from lighter nuclei by fusion thus releases the energy from the net attraction of these particles. For larger nuclei, however, no energy is released, since the force is short-range. Thus, energy is no longer released when such nuclei are made by fusion, instead, fusion reactions create the light elements that power the stars and produce virtually all elements in a process called nucleosynthesis. The fusion of elements in stars releases energy and the mass that always accompanies it
24.
Cryogenics
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In physics, cryogenics is the study of the production and behaviour of materials at very low temperatures. It is not well-defined at what point on the temperature scale refrigeration ends and cryogenics begins, but scientists assume a gas to be cryogenic if it can be liquefied at or below −150 °C. The U. S. National Institute of Standards and Technology has chosen to consider the field of cryogenics as that involving temperatures below −180 °C or −292.00 °F or 93.15 K. A person who studies elements that have been subjected to cold temperatures is called a cryogenicist. Cryogenicists use the Kelvin or Rankine temperature scales present in nature, Cryogenics The branches of physics and engineering that involve the study of very low temperatures, how to produce them, and how materials behave at those temperatures. Cryobiology The branch of biology involving the study of the effects of low temperatures on organisms, cryoconservation of animal genetic resources The conservation of genetic material with the intention of conserving a breed. Cryosurgery The branch of surgery applying very low temperatures to destroy malignant tissue, cryoelectronics The field of research regarding superconductivity at low temperatures. Cryotronics The practical application of cryoelectronics, Cryonics Cryopreserving humans and animals with the intention of future revival. Cryogenics is sometimes used to mean Cryonics in popular culture. The word cryogenics stems from Greek kρύο – cold + genic – having to do with production, Cryogenic fluids with their boiling point in kelvins Liquefied gases, such as liquid nitrogen and liquid helium, are used in many cryogenic applications. Liquid nitrogen is the most commonly used element in cryogenics and is legally purchasable around the world, Liquid helium is also commonly used and allows for the lowest attainable temperatures to be reached. These liquids may be stored in Dewar flasks, which are double-walled containers with a vacuum between the walls to reduce heat transfer into the liquid. Typical laboratory Dewar flasks are spherical, made of glass and protected in a metal outer container, Dewar flasks for extremely cold liquids such as liquid helium have another double-walled container filled with liquid nitrogen. Dewar flasks are named after their inventor, James Dewar, the man who first liquefied hydrogen, thermos bottles are smaller vacuum flasks fitted in a protective casing. Cryogenic barcode labels are used to mark dewar flasks containing these liquids, Cryogenic transfer pumps are the pumps used on LNG piers to transfer liquefied natural gas from LNG carriers to LNG storage tanks, as are cryogenic valves. The field of cryogenics advanced during World War II when scientists found that metals frozen to low temperatures showed more resistance to wear, based on this theory of cryogenic hardening, the commercial cryogenic processing industry was founded in 1966 by Ed Busch. This evolved in the late 1990s into the treatment of other parts, cryogens, such as liquid nitrogen, are further used for specialty chilling and freezing applications. Some chemical reactions, like those used to produce the active ingredients for the popular statin drugs, special cryogenic chemical reactors are used to remove reaction heat and provide a low temperature environment
25.
Deuterium
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Deuterium is one of two stable isotopes of hydrogen. The nucleus of deuterium, called a deuteron, contains one proton and one neutron, whereas the far more common hydrogen isotope, Deuterium has a natural abundance in Earths oceans of about one atom in 6420 of hydrogen. Thus deuterium accounts for approximately 0. 0156% of all the naturally occurring hydrogen in the oceans, the abundance of deuterium changes slightly from one kind of natural water to another. The deuterium isotopes name is formed from the Greek deuteros meaning second, Deuterium was discovered and named in 1931 by Harold Urey. When the neutron was discovered in 1932, this made the structure of deuterium obvious. Soon after deuteriums discovery, Urey and others produced samples of water in which the deuterium content had been highly concentrated. Deuterium is destroyed in the interiors of stars faster than it is produced, other natural processes are thought to produce only an insignificant amount of deuterium. Nearly all deuterium found in nature was produced in the Big Bang 13.8 billion years ago and this is the ratio found in the gas giant planets, such as Jupiter. However, other bodies are found to have different ratios of deuterium to hydrogen-1. This is thought to be as a result of natural isotope separation processes that occur from solar heating of ices in comets, like the water-cycle in Earths weather, such heating processes may enrich deuterium with respect to protium. The analysis of ratios in comets found results very similar to the mean ratio in Earths oceans. This reinforces theories that much of Earths ocean water is of cometary origin, the deuterium/protium ratio of the comet 67P/Churyumov-Gerasimenko, as measured by the Rosetta space probe, is about three times that of earth water. This figure is the highest yet measured in a comet, deuterium/protium ratios thus continue to be an active topic of research in both astronomy and climatology. Deuterium is frequently represented by the chemical symbol D, since it is an isotope of hydrogen with mass number 2, it is also represented by 2H. IUPAC allows both D and 2H, although 2H is preferred, a distinct chemical symbol is used for convenience because of the isotopes common use in various scientific processes. In quantum mechanics the energy levels of electrons in atoms depend on the mass of the system of electron. For hydrogen, this amount is about 1837/1836, or 1.000545, the energies of spectroscopic lines for deuterium and light-hydrogen therefore differ by the ratios of these two numbers, which is 1.000272. The wavelengths of all deuterium spectroscopic lines are shorter than the lines of light hydrogen
26.
Mark 17 nuclear bomb
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The Mark 17 and Mark 24 were the first mass-produced hydrogen bombs deployed by the United States. The two differed in their primary stages, the MK 17/24 bombs were 24 feet 8 inches long,61.4 inches diameter. The Mark 17 had a yield in the range of 10 to 15 megatons TNT equivalent, total production of Mk 17s was 200, and there were 105 Mk 24s produced, all between October 1954 and November 1955. Design and development originated when Los Alamos National Laboratory proposed that a design using lithium deuteride with non-enriched lithium was possible. The new design was designated TX-17 on February 24,1953, the TX-17 and 24 were tested as the Runt device during Operation Castle in 1954. After the successful tests, basic versions of the Mk 17 and 24 were deployed as part of the Emergency Capability program, a total of five EC17 and ten EC24 bombs were rushed into stockpile between April and October 1954. The EC weapons lacked parachutes to delay the time release and their detonation, ensuring the delivery aircraft would be destroyed with the target. Other safety features such as In Flight Insertion and safe arming and fusing devices were also omitted to ensure a quick thermonuclear capability, the EC weapons were quickly replaced with Mk 17 Mod 0 and Mk 24 Mod 0 bombs in October and November 1954. Those weapons included a 64-foot-diameter parachute to allow the aircraft to escape. With the addition of IFI of the Primary capsule to prevent an explosion in case of an accident. The inclusion of a contact fuze upgraded some bombs to the Mod 2 version, allowing the bombs to be used against soft targets, on May 27,1957 a Mark 17 was unintentionally jettisoned from a B-36 just south of Albuquerque, NMs Kirtland AFB. The device fell through the bomb bay doors of the bomber. The devices conventional explosives destroyed it on impact, leaving a crater 7.6 metres in diameter and 3.7 metres deep. Though a chain reaction was impossible because the pits were stored separately on the plane. Although the military cleaned up the site in secret, a few fragments of the bomb - some radioactive still - may be found in the area and it is one of more than 30 known Broken Arrow incidents involving the accidental loss or destruction of a nuclear weapon. Five MK 17/24 casings are on display to the public, National Atomic Museum located at Albuquerque, the Strategic Air Command Memorial at Naval Air Station Fort Worth Joint Reserve Base at Carswell Field in Fort Worth, Texas. The National Museum of the United States Air Force in Dayton, the Strategic Air and Space Museum in Ashland, Nebraska. Castle Air Museum, Atwater, Ca List of nuclear weapons List of military nuclear accidents Castle Bravo Teller-Ulam design Hansen, Nuclear Weapons of the United States, Altglen, PA, Schiffer Publishing,1996, ISBN 0-7643-0063-6
27.
Castle Yankee
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Castle Yankee was the code name given to one of the tests in the Operation Castle series of American tests of thermonuclear bombs. It was originally intended as a test of a TX-16/EC-16 bomb, the test device was replaced with a TX-24/EC-24 bomb which was detonated on May 5,1954, at Bikini Atoll. It released energy equivalent to 13.5 megatons of TNT, Yankee was originally intended to be a test of a TX-16/EC-16, a weaponized version of the large and complex Ivy Mike device. A small number of emergency capability EC-16s were produced, without being tested, the test device, code-named Jughead, had been prepared as a backup in case the non-cryogenic Castle Bravo Shrimp device failed to work. The test of Jughead was cancelled when the Bravo test was successful, Jughead was replaced by the Runt II device, developed from the Castle Romeo Runt device. Externally identical, the difference between them was in the fuel for the fusion stage. While Runt used natural lithium, Runt II used the same partially enriched lithium as the Shrimp device and it was detonated on May 5,1954, at Bikini Atoll of the Marshall Islands, on a barge moored in the middle of the crater from the Castle Union test. Although it had predicted to produce a yield of 6 to 10 megatons, it actually produced a yield of 13.5 megatons. Like the Mike, Bravo and Romeo tests, a percentage of the yield was produced by fast fission of the natural uranium tamper. Of the total yield,7 megatons were from fission, the other 6.5 megatons were from fusion reactions, the high fusion yield was due to the enriched fuel and set a U. S. record that stood until Hardtack Poplar in 1958
28.
United States Air Force
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The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the seven American uniformed services. Initially part of the United States Army, the USAF was formed as a branch of the military on 18 September 1947 under the National Security Act of 1947. It is the most recent branch of the U. S. military to be formed, the U. S. Air Force is a military service organized within the Department of the Air Force, one of the three military departments of the Department of Defense. The Air Force is headed by the civilian Secretary of the Air Force, who reports to the Secretary of Defense, the U. S. Air Force provides air support for surface forces and aids in the recovery of troops in the field. As of 2015, the service more than 5,137 military aircraft,406 ICBMs and 63 military satellites. It has a $161 billion budget with 313,242 active duty personnel,141,197 civilian employees,69,200 Air Force Reserve personnel, and 105,500 Air National Guard personnel. According to the National Security Act of 1947, which created the USAF and it shall be organized, trained, and equipped primarily for prompt and sustained offensive and defensive air operations. The stated mission of the USAF today is to fly, fight, and win in air, space and we will provide compelling air, space, and cyber capabilities for use by the combatant commanders. We will excel as stewards of all Air Force resources in service to the American people, while providing precise and reliable Global Vigilance, Reach and it should be emphasized that the core functions, by themselves, are not doctrinal constructs. The purpose of Nuclear Deterrence Operations is to operate, maintain, in the event deterrence fails, the US should be able to appropriately respond with nuclear options. Dissuading others from acquiring or proliferating WMD, and the means to deliver them, moreover, different deterrence strategies are required to deter various adversaries, whether they are a nation state, or non-state/transnational actor. Nuclear strike is the ability of forces to rapidly and accurately strike targets which the enemy holds dear in a devastating manner. Should deterrence fail, the President may authorize a precise, tailored response to terminate the conflict at the lowest possible level, post-conflict, regeneration of a credible nuclear deterrent capability will deter further aggression. Finally, the Air Force regularly exercises and evaluates all aspects of operations to ensure high levels of performance. Nuclear surety ensures the safety, security and effectiveness of nuclear operations, the Air Force, in conjunction with other entities within the Departments of Defense or Energy, achieves a high standard of protection through a stringent nuclear surety program. The Air Force continues to pursue safe, secure and effective nuclear weapons consistent with operational requirements, adversaries, allies, and the American people must be highly confident of the Air Forces ability to secure nuclear weapons from accidents, theft, loss, and accidental or unauthorized use. This day-to-day commitment to precise and reliable nuclear operations is the cornerstone of the credibility of the NDO mission, positive nuclear command, control, communications, effective nuclear weapons security, and robust combat support are essential to the overall NDO function. OCA is the method of countering air and missile threats, since it attempts to defeat the enemy closer to its source
29.
Boeing B-47 Stratojet
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The Boeing B-47 Stratojet was an American long range, six-engine, turbojet-powered strategic bomber designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraft. The B-47s primary mission was to drop bombs on the Soviet Union. With its engines carried in nacelles under the wing, the B-47 was a major innovation in post-World War II combat jet design. The B-47 entered service with the United States Air Forces Strategic Air Command in 1951 and it never saw combat as a bomber, but was a mainstay of SACs bomber strength during the late 1950s and early 1960s, and remained in use as a bomber until 1965. The B-47 arose from an informal 1943 requirement for a reconnaissance bomber. In December 1944, North American Aviation, the Convair Corp, Boeing and the Glenn Martin Company submitted proposals for the new long-range jet bomber. The USAAF awarded study contracts to all four companies, requiring that North American and Convair concentrate on four-engined designs, while Boeing, the powerplant was to be General Electrics new TG-180 turbojet engine. In May 1945, the von Kármán mission of the Army Air Forces inspected the secret German aeronautics laboratory near Braunschweig, on von Kármáns team was the eminent chief of the technical staff at Boeing, George S. Schairer. He wired his home office, Stop the bomber design, analysis work by Boeing engineer Vic Ganzer suggested an optimum sweepback angle of about 35 degrees. Boeings aeronautical engineers modified their Model 432 design to include swept wings and tail, resulting in the Model 448, the Model 448 retained its four TG-180 jet engines in its forward fuselage, with two more TG-180s in the rear fuselage. The flush-mounted air intakes for the engines were inadequate, while the USAAF disliked the installation of engines within the fuselage. The Army Air Force liked this new configuration, and so Boeings team of engineers continued to refine it, with the engines being moved further inboard. As the landing gear arrangement made rotation impossible, the gear was designed so that the aircraft rested on the ground at the proper angle for takeoff. The USAAF was very pleased with the refined Model 450 design, and in April 1946, the first XB-47 was rolled out on 12 September 1947, a few days before the USAAF became a separate service, the U. S. Air Force, on 18 September 1947. The XB-47 prototype flew its first flight on 17 December 1947, with the test pilots Robert Robbins and it flew from Boeing Field in Seattle to the Moses Lake Airfield in central Washington state, in a flight that lasted just 27 minutes, with no major problems. In Feb.1949, Russ Schleeh and Joe Howell broke all coast-to-coast speed records flying from Moses Lake Air Force Base to Andrews Air Force Base and they averaged 607.8 miles per hour. During early tests of the XB-47 prototype, the canopy came off at high speed, the copilot safely landed the aircraft. This resulted in a redesign, and the hiring of pilot Tex Johnston as chief test pilot
30.
Convair B-58 Hustler
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The Convair B-58 Hustler was the first operational jet bomber capable of Mach 2 flight. The aircraft was designed by Convair engineer Robert H. Widmer and it used a delta wing, which was also employed by Convair fighters such as the F-102, with four General Electric J79 engines in pods under the wing. It carried five weapons, four on pylons under the wings. Replacing the Boeing B-47 Stratojet medium bomber, it was intended to fly at high altitudes. The B-58 received a deal of notoriety due to its sonic boom. This resulted in only an operational career between 1960 and 1970 when the B-58 was succeeded by the smaller, swing-wing FB-111A. The proposed bombers design and development was to begin less than two years after sustained supersonic flight had successfully been achieved, a number of contractors submitted bids to perform the generalized study including Boeing, Convair, Curtiss, Douglas, Martin and North American Aviation. The delta planform had good internal volume for support systems and fuel, plus a low wing loading, the final Convair proposal, coded FZP-110, was a radical two-place, delta wing bomber design powered by General Electric J53 engines. The performance estimates included a 1,000 mph speed and a 3,000 statute mile range, the USAF chose Boeing and Convair to proceed to a Phase 1 study. The Convair MX-1626 evolved further into a refined proposal redesignated the MX-1964. In February 1953, the Air Force issued a contract for development of Convairs design, the resulting B-58 design was the first true USAF supersonic bomber program. The Convair design was based on a wing with a leading-edge sweep of 60° with four General Electric J79-GE-1 turbojet engines. Although its large wing made for relatively low wing loading, it proved to be well suited for low-altitude. It seated three in separated tandem cockpits, later versions gave each crew member a novel ejection capsule that made it possible to eject at an altitude of 70,000 ft at speeds up to Mach 2. The capsule would float, and the crewmember could open the clamshell, in an unusual test program, live bears and chimpanzees were successfully used to test the ejection system. The XB-70 would use a similar system, because of heat generated at Mach 2 cruise, not only the crew compartment, but the wheel wells and electronics bay were pressurized and air conditioned. The B-58 utilized one of the first extensive applications of aluminum honeycomb panels, the pilots cockpit was fairly conventional for a large multiengine aircraft. The electronic controls were ambitious and advanced for the day, the navigator and DSOs cockpits featured wraparound dashboards with warning lights and buttons, and automatic voice messages and warnings from a tape system were audible through the helmet sets
31.
Dimensional analysis
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Converting from one dimensional unit to another is often somewhat complex. Dimensional analysis, or more specifically the method, also known as the unit-factor method, is a widely used technique for such conversions using the rules of algebra. The concept of physical dimension was introduced by Joseph Fourier in 1822, Physical quantities that are measurable have the same dimension and can be directly compared to each other, even if they are originally expressed in differing units of measure. If physical quantities have different dimensions, they cannot be compared by similar units, hence, it is meaningless to ask whether a kilogram is greater than, equal to, or less than an hour. Any physically meaningful equation will have the dimensions on their left and right sides. Checking for dimensional homogeneity is an application of dimensional analysis. Dimensional analysis is routinely used as a check of the plausibility of derived equations and computations. It is generally used to categorize types of quantities and units based on their relationship to or dependence on other units. Many parameters and measurements in the sciences and engineering are expressed as a concrete number – a numerical quantity. Often a quantity is expressed in terms of other quantities, for example, speed is a combination of length and time. Compound relations with per are expressed with division, e. g.60 mi/1 h, other relations can involve multiplication, powers, or combinations thereof. A base unit is a unit that cannot be expressed as a combination of other units, for example, units for length and time are normally chosen as base units. Units for volume, however, can be factored into the units of length. Sometimes the names of units obscure that they are derived units, for example, an ampere is a unit of electric current, which is equivalent to electric charge per unit time and is measured in coulombs per second, so 1 A =1 C/s. Similarly, one newton is 1 kg⋅m/s2, percentages are dimensionless quantities, since they are ratios of two quantities with the same dimensions. In other words, the % sign can be read as 1/100, derivatives with respect to a quantity add the dimensions of the variable one is differentiating with respect to on the denominator. Thus, position has the dimension L, derivative of position with respect to time has dimension LT−1 – length from position, time from the derivative, the second derivative has dimension LT−2. In economics, one distinguishes between stocks and flows, a stock has units of units, while a flow is a derivative of a stock, in some contexts, dimensional quantities are expressed as dimensionless quantities or percentages by omitting some dimensions
32.
Unguided bomb
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This described all aircraft bombs in general service until the latter half of World War II, and the vast majority until the late 1980s. Then, with the increased use of precision-guided munitions, a retronym was needed to separate smart bombs from free-fall bombs. Dumb bomb was used for a time, but many military circles felt it sounded too trite, previously, they were also referred to as iron bombs. Unguided bombs typically use a contact fuse for detonation upon impact, one alternative is a fuse with an altimeter, to cause an air burst at the desired altitude. The retarded bomb uses a method of creating increased aerodynamic drag, such as a parachute, ballute. However, these bombs are less accurate than conventional free-fall bombs, generally the high-drag tail replaces the low-drag so that the same bomb can be configured for either mode of attack during weapons preparation. High-drag bombs can also be dropped in low-drag mode if the pilot selects this option in the weapon system
33.
Lithium
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Lithium is a chemical element with the symbol Li and atomic number 3. It is a soft, silver-white metal belonging to the metal group of chemical elements. Under standard conditions, it is the lightest metal and the least dense solid element, like all alkali metals, lithium is highly reactive and flammable. For this reason, it is stored in mineral oil. When cut open, it exhibits a metallic luster, but contact with moist air corrodes the surface quickly to a silvery gray. Because of its reactivity, lithium never occurs freely in nature, and instead, appears only in compounds. Lithium occurs in a number of minerals, but due to its solubility as an ion, is present in ocean water and is commonly obtained from brines. On a commercial scale, lithium is isolated electrolytically from a mixture of lithium chloride, the nucleus of the lithium atom verges on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides. Because of its relative instability, lithium is less common in the solar system than 25 of the first 32 chemical elements even though the nuclei are very light in atomic weight. For related reasons, lithium has important links to nuclear physics, the transmutation of lithium atoms to helium in 1932 was the first fully man-made nuclear reaction, and lithium-6 deuteride serves as a fusion fuel in staged thermonuclear weapons. These uses consume more than three quarters of lithium production, Lithium is found in variable amounts in foods, primary food sources are grains and vegetables, in some areas, the drinking water also provides significant amounts of the element. Human dietary lithium intakes depend on location and the type of foods consumed, traces of lithium were detected in human organs and fetal tissues already in the late 19th century, leading to early suggestions as to possible specific functions in the organism. However, it took another century until evidence for the essentiality of lithium became available, in studies conducted from the 1970s to the 1990s, rats and goats maintained on low-lithium rations were shown to exhibit higher mortalities as well as reproductive and behavioral abnormalities. Lithium appears to play an important role during the early fetal development as evidenced by the high lithium contents of the embryo during the early gestational period. The available experimental evidence now appears to be sufficient to accept lithium as essential, the lithium ion Li+ administered as any of several lithium salts has proven to be useful as a mood-stabilizing drug in the treatment of bipolar disorder in humans. Like the other metals, lithium has a single valence electron that is easily given up to form a cation. Because of this, lithium is a conductor of heat and electricity as well as a highly reactive element. Lithiums low reactivity is due to the proximity of its electron to its nucleus
34.
Isotopes of lithium
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Naturally occurring lithium is composed of two stable isotopes, lithium-6 and lithium-7, with the latter being far more abundant, about 92.5 percent of the atoms. Both of the isotopes have an unexpectedly low nuclear binding energy per nucleon when compared with the adjacent lighter and heavier elements. The longest-lived radioisotope of lithium is lithium-8, which has a half-life of just 838 milliseconds, lithium-9 has a half-life of 178 milliseconds, and lithium-11 has a half-life of about 8.6 milliseconds. All of the isotopes of lithium have half-lives that are shorter than 10 nanoseconds. Lithium-7 and lithium-6 are two of the primordial nuclides that were produced in the Big Bang, with lithium-7 to be 10−9 of all primordial nuclides, a small percentage of lithium-6 is also known to be produced by nuclear reactions in certain stars. The isotopes of lithium separate somewhat during a variety of geological processes, lithium ions replace magnesium or iron in certain octahedral locations in clays, and lithium-6 is sometimes preferred over lithium-7. This results in some enrichment of lithium-7 in geological processes, lithium-6 is an important isotope in nuclear physics because when it is bombarded with neutrons, tritium is produced. Lithium-6 has a greater affinity than lithium-7 for the element mercury, when an amalgam of lithium and mercury is added to solutions containing lithium hydroxide, the lithium-6 becomes more concentrated in the amalgam and the lithium-7 more in the hydroxide solution. The colex separation method makes use of this by passing a counter-flow of amalgam, the fraction of lithium-6 is preferentially drained by the mercury, but the lithium-7 flows mostly with the hydroxide. At the bottom of the column, the lithium is separated from the amalgam, at the top, the lithium hydroxide solution is electrolyzed to liberate the lithium-7 fraction. The enrichment obtained with this method varies with the column length, lithium is heated to a temperature of about 550 °C in a vacuum. Lithium atoms evaporate from the surface and are collected on a cold surface positioned a few centimetres above the liquid surface. Since lithium-6 atoms have a mean free path, they are collected preferentially. The theoretical separation efficiency is about 8.0 percent, a multistage process may be used to obtain higher degrees of separation. Lithium-4 contains three protons and one neutron and it is the shortest-lived known isotope of lithium, with a half-life of about 9. 1×10−23 seconds and decays by proton emission to helium-3. Lithium-4 can be formed as an intermediate in some nuclear fusion reactions, lithium-6 is valuable as the source material for the production of tritium and as an absorber of neutrons in nuclear fusion reactions. Natural lithium contains about 7.5 percent lithium-6, with the rest being lithium-7, large amounts of lithium-6 have been separated out for placing into hydrogen bombs. The separation of lithium-6 has by now ceased in the large thermonuclear powers, lithium-6 is one of only three stable isotopes with a spin of 1 and has the smallest nonzero nuclear electric quadrupole moment of any stable nucleus
35.
Mark 14 nuclear bomb
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SC/MP based computer system see MK14. For the torpedo see Mark 14 torpedo, the Mark 14 nuclear bomb was a 1950s Strategic thermonuclear weapon, the first solid-fuel staged hydrogen bomb. It was a design, and only five units were produced in early 1954. It was tested in April 1954 during the Castle Union nuclear test and had a yield of 6.9 Mt, the bomb is often listed as the TX-14 or EC-14. It has also referred to as the Alarm Clock device though it has nothing to do with the design by the same name proposed earlier by Edward Teller. The fusion fuel used by the bomb was 95% enriched Lithium isotope 6 lithium deuteride, the Castle Bravo test showed that unenriched Lithium isotope 7 functioned as well for nuclear fusion reactions as isotope 6. The Mk-14 bomb had a diameter of 61.4 inches and they weighed between 28,950 and 31,000 pounds, and used a 64 feet parachute. The version tested at Castle Union used a RACER IV primary, by 1956, the components of all of the five produced Mk-14 bombs had been recycled into Mark 17s. List of nuclear weapons Citations Further reading Hansen, Chuck, Swords of Armageddon, pDF-2.67 Mb.2,600 pages, Sunnyvale, California, Chucklea Publications,1995,2007
36.
United States dollar
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The United States dollar is the official currency of the United States and its insular territories per the United States Constitution. It is divided into 100 smaller cent units, the circulating paper money consists of Federal Reserve Notes that are denominated in United States dollars. The U. S. dollar was originally commodity money of silver as enacted by the Coinage Act of 1792 which determined the dollar to be 371 4/16 grain pure or 416 grain standard silver, the currency most used in international transactions, it is the worlds primary reserve currency. Several countries use it as their currency, and in many others it is the de facto currency. Besides the United States, it is used as the sole currency in two British Overseas Territories in the Caribbean, the British Virgin Islands and Turks and Caicos Islands. A few countries use the Federal Reserve Notes for paper money, while the country mints its own coins, or also accepts U. S. coins that can be used as payment in U. S. dollars. After Nixon shock of 1971, USD became fiat currency, Article I, Section 8 of the U. S. Constitution provides that the Congress has the power To coin money, laws implementing this power are currently codified at 31 U. S. C. Section 5112 prescribes the forms in which the United States dollars should be issued and these coins are both designated in Section 5112 as legal tender in payment of debts. The Sacagawea dollar is one example of the copper alloy dollar, the pure silver dollar is known as the American Silver Eagle. Section 5112 also provides for the minting and issuance of other coins and these other coins are more fully described in Coins of the United States dollar. The Constitution provides that a regular Statement and Account of the Receipts and that provision of the Constitution is made specific by Section 331 of Title 31 of the United States Code. The sums of money reported in the Statements are currently being expressed in U. S. dollars, the U. S. dollar may therefore be described as the unit of account of the United States. The word dollar is one of the words in the first paragraph of Section 9 of Article I of the Constitution, there, dollars is a reference to the Spanish milled dollar, a coin that had a monetary value of 8 Spanish units of currency, or reales. In 1792 the U. S. Congress passed a Coinage Act, Section 20 of the act provided, That the money of account of the United States shall be expressed in dollars, or units. And that all accounts in the offices and all proceedings in the courts of the United States shall be kept and had in conformity to this regulation. In other words, this act designated the United States dollar as the unit of currency of the United States, unlike the Spanish milled dollar the U. S. dollar is based upon a decimal system of values. Both one-dollar coins and notes are produced today, although the form is significantly more common
37.
Hans Bethe
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For most of his career, Bethe was a professor at Cornell University. During World War II, he was head of the Theoretical Division at the secret Los Alamos laboratory which developed the first atomic bombs. After the war, Bethe also played an important role in the development of the hydrogen bomb, Bethe later campaigned with Albert Einstein and the Emergency Committee of Atomic Scientists against nuclear testing and the nuclear arms race. He helped persuade the Kennedy and Nixon administrations to sign, respectively, freeman Dyson, once one of his students, called him the supreme problem-solver of the 20th century. Bethe was born in Strasbourg, which was part of Germany, on July 2,1906, the only child of Anna and Albrecht Bethe. Although his mother, the daughter of a professor at the University of Strasbourg, was Jewish, despite having a religious background, he was not religious in later life, and described himself as an atheist. His father accepted a position as professor and director of the Institute of Physiology at the University of Kiel in 1912, and he was initially schooled privately by a professional teacher as part of a group of eight girls and boys. The family moved again in 1915 when his father became the head of the new Institute of Physiology at the University of Frankfurt am Main, Bethe attended the Goethe-Gymnasium in Frankfurt, Germany. His education was interrupted in 1916, when he contracted tuberculosis, by 1917, he had recovered sufficiently to attend the local realschule, and the following year he was sent to the Odenwaldschule, a private, coeducational boarding school. He attended the Goethe-Gymnasium again for his three years of secondary schooling, from 1922 to 1924. Having passed his abitur, Bethe entered the University of Frankfurt in 1924 and he decided to major in chemistry. Bethe entered the University of Munich in April 1926, where Sommerfeld took him on as a student on Meissners recommendation, Sommerfeld taught an advanced course on differential equations in physics, which Bethe enjoyed. Because he was such a renowned scholar, Sommerfeld frequently received advance copies of scientific papers, when Bethe arrived, Sommerfeld had just received Erwin Schrödingers papers on wave mechanics. For his PhD thesis, Sommerfeld suggested that Bethe examine electron diffraction in crystals, as a starting point, Sommerfeld suggested Paul Ewalds 1914 paper on X-ray diffraction in crystals. Bethe later recalled that he became too ambitious, and, in pursuit of greater accuracy, when he met Wolfgang Pauli for the first time, Pauli told him, After Sommerfelds tales about you, I had expected much better from you than your thesis. I guess from Pauli, Bethe later recalled, that was a compliment, after Bethe received his doctorate, Erwin Madelung offered him an assistantship in Frankfurt, and in September 1928 Bethe moved in with his father, who had recently divorced his mother. His father met Vera Congehl earlier that year, and married her in 1929 and they had two children, Doris, born in 1933, and Klaus, born in 1934. Bethe did not find the work in Frankfurt very stimulating, while there, he wrote what he considered to be his greatest paper, Zur Theorie des Durchgangs schneller Korpuskularstrahlen durch Materie
38.
Castle Bravo
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Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll, Marshall Islands, as part of Operation Castle. Detonated on March 1,1954, the device was the most powerful nuclear device detonated by the United States, and its first lithium-deuteride-fueled thermonuclear weapon. Castle Bravos yield was 15 megatons of TNT,2.5 times more than predicted, fallout from the detonation fell on residents of Rongelap and Utirik atolls and spread around the world. The islanders were not evacuated until three days later and suffered radiation sickness, twenty-three crewmembers of the Japanese fishing vessel Daigo Fukuryū Maru were also contaminated by fallout, experiencing acute radiation syndrome. The blast incited international reaction over atmospheric thermonuclear testing, the Bravo Crater is located at 11°41′50″N 165°16′19″E. The remains of the Castle Bravo causeway are at 11°42′6″N 165°17′7″E, the Castle Bravo device was housed in a cylinder that weighed 23,500 pounds and measured 179.5 inches in length and 53.9 inches in diameter. The primary device was a COBRA tritium-boosted atomic bomb provided by Los Alamos Scientific Laboratory and it was located at the end of the device, which, as seen in the declassified film, shows a small cone projecting from the ballistic case. This cone is the part of the parabola that was used to focus the radiation emanating from the primary to the secondary, the device was called SHRIMP and had the same basic configuration as the Ivy Mike wet device, except with a different type of fusion fuel. SHRIMP used lithium deuteride, which is solid at room temperature, Ivy Mike used cryogenic liquid deuterium, Castle Bravo was the first test by the United States of a practical deliverable fusion bomb, even though the TX-21 as proof-tested in the Bravo event was not weaponized. The successful test rendered obsolete the cryogenic design used by Ivy Mike and its derivative, the JUGHEAD. It also used a 7075 aluminium 9.5 cm thick ballistic case, the SHRIMP was at least in theory and in many aspects identical in geometry to the RUNT and RUNT II devices later proof-fired in Castle Romeo and Castle Yankee respectively. On paper it was a version of these devices, and its origins can be traced back to the spring. The United States Air Force indicated the importance of lighter weapons for delivery by the B-47 Stratojet. Los Alamos National Laboratory responded to this indication with an enriched version of the RUNT scaled down to a 3/4 scale radiation-implosion system called the SHRIMP. The proposed weight reduction would provide the Air Force with a more versatile deliverable gravity bomb. The final version tested in Castle used partially enriched lithium as its fusion fuel, natural lithium is a mixture of lithium-6 and lithium-7 isotopes. The enriched lithium used in Bravo was nominally 40% lithium-6, the fuel slugs varied in enrichment from 37 to 40% in 6Li, and the slugs with lower enrichment were positioned at the end of the fusion-fuel chamber, away from the primary. The mixture cost about 4.54 USD/g at that time, the fusion burn efficiency was ~25. 1%, the highest attained efficiency of the first TN weapon generation
39.
Lawson criterion
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In nuclear fusion research, the Lawson criterion, first derived on fusion reactors by John D. As originally formulated the Lawson criterion gives a minimum required value for the product of the plasma density ne, later analysis suggested that a more useful figure of merit is the triple product of density, confinement time, and plasma temperature T. The triple product also has a minimum required value, and the name Lawson criterion often refers to this inequality, the central concept of the Lawson criterion is the energy balance for any fusion power plant, using a hot plasma. This is shown below, Net Power = Efficiency × Net Power is the power beyond that needed internally for the process to proceed in any fusion power plant. Efficiency how much energy is needed to drive the device and how well it collects power, fusion is rate of energy generated by the fusion reactions. Radiation is the energy lost as light, leaving the plasma, conduction is the energy lost, as mass leaves the plasma. Lawson calculates the rate by assuming that any fusion reactor contains a hot plasma cloud which has a Gaussian curve of energy. Based on that assumption, he estimates the first term, the energy coming from a hot cloud using the volumetric fusion equation. For his analysis, Lawson ignores conduction losses, in reality this is nearly impossible, practically all systems lose energy through mass leaving. Lawson then estimated the losses using the equation below. P B =1.4 ⋅10 −34 ⋅ N2 ⋅ T1 /2 W c m 3 where N is the density of the cloud. When applied to the fusor Lawsons analysis is used as an argument that conduction and radiation losses are the key impediment to reaching net power, fusors use a voltage drop to accelerate and collide ions, resulting in fusion. The voltage drop is generated by wire cages, and these cages conduct away particles, polywell are improvements on this design, designed to reduce conduction losses by removing the wire cages which cause them. Regardless, it is argued that radiation is still a major impediment, the confinement time τ E measures the rate at which a system loses energy to its environment. Thermal energy must therefore be added to it at the rate the plasma loses energy. The plasma loses energy through mass or light leaving the chamber, for illustration, the Lawson criterion for the deuterium–tritium reaction will be derived here, but the same principle can be applied to other fusion fuels. It will also be assumed that all species have the same temperature, that there are no ions present other than fuel ions, and that deuterium and tritium are present in the optimal 50-50 mixture. Ion density then equals electron density and the density of both electrons and ions together is given by W =3 n k B T where k B is the Boltzmann constant
40.
Partial pressure
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In a mixture of gases, each gas has a partial pressure which is the hypothetical pressure of that gas if it alone occupied the entire volume of the original mixture at the same temperature. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture. Gases dissolve, diffuse, and react according to their partial pressures and this general property of gases is also true in chemical reactions of gases in biology. For example, the amount of oxygen for human respiration. This is true across a wide range of different concentrations of oxygen present in various inhaled breathing gases or dissolved in blood. Daltons law expresses the fact that the pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture. This equality arises from the fact that in a gas the molecules are so far apart that they do not interact with each other. Most actual real-world gases come very close to this ideal. For example, given an ideal gas mixture of nitrogen, hydrogen and ammonia, the partial volume of a particular gas in a mixture is the volume of one component of the gas mixture. It is useful in gas mixtures, e. g. air, to focus on one particular gas component, most often the term is used to describe a liquids tendency to evaporate. It is a measure of the tendency of molecules and atoms to escape from a liquid or a solid, the higher the vapor pressure of a liquid at a given temperature, the lower the normal boiling point of the liquid. The vapor pressure chart displayed has graphs of the vapor pressures versus temperatures for a variety of liquids, as can be seen in the chart, the liquids with the highest vapor pressures have the lowest normal boiling points. For example, at any temperature, methyl chloride has the highest vapor pressure of any of the liquids in the chart. It also has the lowest normal boiling point, which is where the pressure curve of methyl chloride intersects the horizontal pressure line of one atmosphere of absolute vapor pressure. It is possible to work out the equilibrium constant for a reaction involving a mixture of gases given the partial pressure of each gas. However, the reaction kinetics may either oppose or enhance the equilibrium shift, in some cases, the reaction kinetics may be the overriding factor to consider. Gases will dissolve in liquids to an extent that is determined by the equilibrium between the gas and the gas that has dissolved in the liquid. This statement is known as Henrys law and the constant k is quite often referred to as the Henrys law constant
41.
Nuclear weapon design
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Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types, in many existing designs, the explosive energy of deployed devices is derived primarily from nuclear fission, not fusion. Pure fission weapons were the first nuclear weapons built and have so far been the type ever used in warfare. Implosion, a mass of either material is surrounded by high explosives that compress the mass. The implosion method can use either uranium or plutonium as fuel, the gun method only uses uranium. Boosted fission weapons improve on the implosion design, the high pressure and temperature environment at the center of an exploding fission weapon compresses and heats a mixture of tritium and deuterium gas. The hydrogen fuses to form helium and free neutrons, boosting can more than double the weapons fission energy release. Staged thermonuclear weapons are essentially a chain of fusion-boosted fission weapons, the secondary stage is imploded by x-ray energy from the first stage, called the primary. This radiation implosion is much more effective than the high-explosive implosion of the primary, consequently, the secondary can be many times more powerful than the primary, without being bigger. The secondary can be designed to maximize fusion energy release, but in most designs fusion is employed only to drive or enhance fission, as it is in the primary. More stages could be added and conceptual designs incorporating up to seven have been produced, pure fusion weapons have not been invented. Such weapons, though, would produce far less radioactive fallout than current designs, pure fission weapons historically have been the first type to be built by a nation state. Most known innovations in nuclear weapon design originated in the United States, although some were developed independently by other states. In early news accounts, pure fission weapons were called atomic bombs or A-bombs, Weapons involving fusion were called hydrogen bombs or H-bombs, also a misnomer since their energy comes mostly from fission. Practitioners favored the terms nuclear and thermonuclear, respectively, the term thermonuclear refers to the high temperatures required to initiate fusion. It omits the equally important factor of radiation pressure, which was considered secret at the time the term became widespread, many nuclear weapon terms similarly obfuscate because of their origin in a classified environment. Nuclear fission separates or splits heavier atoms to form lighter atoms, Nuclear fusion combines together lighter atoms to form heavier atoms. In some ways, fission and fusion are opposite and complementary reactions, to understand how nuclear weapons are designed, it is useful to know the important similarities and differences between fission and fusion
42.
Copper
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Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
43.
Hohlraum
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In radiation thermodynamics, a hohlraum is a cavity whose walls are in radiative equilibrium with the radiant energy within the cavity. This idealized cavity can be approximated in practice by making a small perforation in the wall of a container of any opaque material. The radiation escaping through such a perforation will be an approximation to blackbody radiation at the temperature of the interior of the container. The indirect drive approach to inertial confinement fusion is as follows, the radiation source is pointed at the interior of the hohlraum, which absorbs and re-radiates the energy as X-rays, rather than on the capsule itself, a process known as indirect drive. The advantage to this approach is that the energy is re-radiated in a more symmetric fashion than would be possible in the direct drive approach. The X-ray intensity around the capsule must be symmetrical to avoid hydrodynamic instabilities during compression. Earlier designs had radiators at the ends of the hohlraum, with a judicious choice of absorbing materials, this arrangement, referred to as a distributed-radiator target, gives better X-ray symmetry and target gain in simulations than earlier designs. The term hohlraum is also used to describe the casing of a thermonuclear bomb following the Teller-Ulam design, the casings purpose is to contain and focus the energy of the primary stage in order to implode the secondary stage. NIF Hohlraum – High resolution picture at Lawrence Livermore National Laboratory
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Gold
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Gold is a chemical element with symbol Au and atomic number 79. In its purest form, it is a bright, slightly yellow, dense, soft, malleable. Chemically, gold is a metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions, Gold often occurs in free elemental form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the element silver and also naturally alloyed with copper. Less commonly, it occurs in minerals as gold compounds, often with tellurium, golds atomic number of 79 makes it one of the higher numbered, naturally occurring elements. It is thought to have produced in supernova nucleosynthesis, from the collision of neutron stars. Because the Earth was molten when it was formed, almost all of the present in the early Earth probably sank into the planetary core. Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of acid and hydrochloric acid. Gold also dissolves in solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, but this is not a chemical reaction, as a precious metal, gold has been used for coinage, jewelry, and other arts throughout recorded history. A total of 186,700 tonnes of gold is in existence above ground, the world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. Gold is also used in infrared shielding, colored-glass production, gold leafing, certain gold salts are still used as anti-inflammatories in medicine. As of 2014, the worlds largest gold producer by far was China with 450 tonnes, Gold is cognate with similar words in many Germanic languages, deriving via Proto-Germanic *gulþą from Proto-Indo-European *ǵʰelh₃-. The symbol Au is from the Latin, aurum, the Latin word for gold, the Proto-Indo-European ancestor of aurum was *h₂é-h₂us-o-, meaning glow. This word is derived from the root as *h₂éu̯sōs, the ancestor of the Latin word Aurora. This etymological relationship is presumably behind the frequent claim in scientific publications that aurum meant shining dawn, Gold is the most malleable of all metals, a single gram can be beaten into a sheet of 1 square meter, and an avoirdupois ounce into 300 square feet. Gold leaf can be thin enough to become semi-transparent
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