The basics of the Teller–Ulam configuration: a fission bomb uses radiation to compress and heat a separate section of fusion fuel.

The Teller–Ulam design is a nuclear weapon design which is used in megaton-range thermonuclear weapons, and is more colloquially referred to as "the secret of the hydrogen bomb". Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate It is named after two of its chief contributors, Hungarian-born physicist Edward Teller and Polish-born mathematician Stanisław Ulam, who developed the design in 1951. Edward Teller (original Hungarian name Teller Ede) (January 15 1908 &ndash September 9 2003 was a Hungarian -American theoretical Physicist Stanisław Marcin Ulam ( April 13, 1909 &ndash May 13, 1984) was a Polish Mathematician who participated in the Manhattan The idea is thought to pertain specifically to the use of a fission bomb "trigger" placed near an amount of fusion fuel, known as "staging", and the use of "radiation implosion" to compress the fusion fuel before igniting it. Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus The term radiation implosion describes the process behind a class of devices which use high levels of Electromagnetic radiation to compress a target There are a number of other additions and variations to this idea posited by different sources.

The first device to be based on this principle was detonated by the United States in the "Ivy Mike" nuclear test in 1952. The United States of America —commonly referred to as the Ivy Mike was the codename given to the first US test of a fusion device where a major part of the explosive yield came from fusion Nuclear weapons tests are experiments carried out to determine the effectiveness yield and explosive capability of Nuclear weapons Throughout the twentieth century most nations In the Soviet Union, this design was known as Andrei Sakharov's "Third Idea". The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 Andrei Dmitrievich Sakharov (Андре́й Дми́триевич Са́харов (May 21 1921 – December 14 1989 was an eminent Soviet nuclear Physicist Similar devices were developed by the United Kingdom, France and China though no specific codenames are known for their designs. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located This article is about the country For a topic outline on this subject see List of basic France topics. Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES The most powerful thermonuclear device ever tested was the 50 to 58 megaton Soviet Tsar Bomba test. Tsar Bomba (ru Царь-бомба literally " King Bomb" is the Western name for the RDS-220 hydrogen bomb (codenamed "Иван" (Ivan by its ^[1][2]

Public body of knowledge concerning nuclear weapon design

Detailed knowledge of actual fission and fusion weapons is classified to some degree in virtually every industrialized nation. In the United States, such "knowledge" can by default be classified as Restricted Data, even if it is created by persons who are not government employees or associated with weapons programs, in a legal doctrine known as "born secret" (though the constitutional standing of the doctrine has been at times called into question, see United States v. The Progressive, et al.). " Born secret " and " born classified " are both terms which refer to a policy of information being classified from the moment of its inception usually United States of America v Progressive Inc Erwin Knoll Samuel Day Jr Born-secret is rarely invoked for cases of private speculation. The official policy of the United States Department of Energy has been not to acknowledge the leaking of design information, as such acknowledgment would potentially validate the information as accurate. The United States Department of Energy ( DOE) is a Cabinet -level department of the United States government responsible for energy policy In a small number of prior cases, the U. S. government has attempted to censor weapons information in the public press, with limited success. Prior restraint is a Legal term referring to a Government 's actions that prevent materials from being published

Though large quantities of vague data have been officially released, and larger quantities of vague data have been unofficially leaked by ex-bomb designers, most public descriptions of nuclear weapon design details rely to some degree on speculation, reverse engineering from known information, or comparison with similar fields of physics (inertial confinement fusion is the primary example). Inertial confinement fusion ( ICF) is a process where Nuclear fusion reactions are initiated by heating and compressing a fuel target typically in the form of Such processes have resulted in a body of unclassified knowledge about nuclear bombs which is generally consistent with official unclassified information releases, related physics, and is thought to be internally consistent, though there are some points of interpretation which are still considered open. The state of public knowledge about the Teller–Ulam design has been most reliably shaped from a few specific incidences outlined in a section below.

Basic principle

The basic principle of the Teller–Ulam configuration is the idea that different parts of a thermonuclear weapon can be chained together in "stages", with the detonation of each stage providing the energy to ignite the next stage. At a bare minimum, this implies a primary section which consists of a fission bomb (a "trigger"), and a secondary section which consists of fusion fuel. Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may Because of the staged design, it is thought that a tertiary section, again of fusion fuel, could be added as well, based on the same principle of the secondary. The energy released by the primary compresses the secondary through the concept of "radiation implosion", at which point it is heated and undergoes nuclear fusion. The term radiation implosion describes the process behind a class of devices which use high levels of Electromagnetic radiation to compress a target In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus

One possible version of the Teller–Ulam configuration.

Surrounding the other components is a hohlraum or radiation case, a container which traps the first stage or primary's energy inside temporarily. In Radiation Thermodynamics, a hohlraum (a German Loanword, originally a non-specific word for "hollow area" or "cavity" The outside of this radiation case, which is also normally the outside casing of the bomb, is the only direct visual evidence publicly available of any thermonuclear bomb component's configuration. Numerous photographs of various thermonuclear bomb exteriors have been declassified. ^[3]

The primary is thought to be a standard implosion method fission bomb, though likely with a core boosted by small amounts of fusion fuel for extra efficiency; the fusion fuel releases excess neutrons when heated and compressed, inducing additional fission. Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate 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 This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Generally, an entity with the capacity to create a thermonuclear bomb has already mastered the ability to engineer boosted fission. When fired, the plutonium-239 (Pu-239) and/or uranium-235 (U-235) core would be compressed to a smaller sphere by special layers of conventional high explosives arranged around it in a lens pattern, initiating the nuclear chain reaction that powers the conventional "atomic bomb". Plutonium-239 is an Isotope of Plutonium. Plutonium-239 is the primary Fissile isotope used for the production of Nuclear weapons although Uranium-235 is an isotope of uranium that differs from the element's other common isotope Uranium-238, by its ability to cause a rapidly expanding fission A nuclear chain reaction occurs when one Nuclear reaction causes an average of one or more nuclear reactions thus leading to a self-propagating number of these reactions

The secondary is usually shown as a column of fusion fuel and other components wrapped in many layers. A column in Structural engineering is a vertical structural element that transmits through compression, the weight of the structure above to other structural Around the column is first a "pusher-tamper", a heavy layer of unenriched uranium-238 (U-238) or lead which serves to help compress the fusion fuel (and, in the case of uranium, may eventually undergo fission itself). Uranium-238 (U-238 is the most common isotope of Uranium found in nature Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Inside this is the fusion fuel itself, usually a form of lithium deuteride, which is used because it is easier to weaponize than liquified tritium/deuterium gas (compare the success of the cryogenic deuterium-based Ivy Mike experiment to the (over)success of the lithium deuteride-based Castle Bravo experiment). Lithium hydride ( Li[[Hydride H]] is the compound of Lithium and hydrogen Ivy Mike was the codename given to the first US test of a fusion device where a major part of the explosive yield came from fusion Castle Bravo was the Code name given to the first US test of a so-called dry fuel thermonuclear Hydrogen bomb device detonated on March 1, This dry fuel, when bombarded by neutrons, produces tritium, a heavy isotope of hydrogen which can undergo nuclear fusion, along with the deuterium present in the mixture. This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth (See the article on nuclear fusion for a more detailed technical discussion of fusion reactions. In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus ) Inside the layer of fuel is the "spark plug", a hollow column of fissile material (plutonium-239 or uranium-235) which, when compressed, can itself undergo nuclear fission (because of the shape, it is not a critical mass without compression). A critical mass is the smallest amount of Fissile material needed for a sustained Nuclear chain reaction. The tertiary, if one is present, would be set below the secondary and probably be made up of the same materials. ^[4][5]

A more simplified explanation of the above would be as follows:

1. An implosion assembly type of fission bomb is exploded. Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate This is the primary stage. If a small amount of tritium gas is placed near the primary explosion, it will be compressed and a fusion reaction will occur; the released neutrons from this fusion reaction will induce further fission in the plutonium-239 or uranium-235 used in the primary stage. Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. The use of fusion fuel to enhance the efficiency of a fission reaction is called boosting. Without boosting, a large portion of the fissile material will remain unreacted; the Little Boy and Fat Man bombs had an efficiency of only 1. Little Boy was the Codename of the Atomic bomb, developed via the "Manhattan Project" which was dropped on Hiroshima, on August 6 1945 by the "Fat Man" is the codename for the Atomic bomb that was detonated over Nagasaki, Japan, by the United States on August 9 Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate 4% and 14%, respectively, because they were unboosted.
2. Energy released in the primary stage is transferred to the secondary (or fusion) stage. The exact mechanism whereby this happens is unknown (see speculation regarding this below). This energy compresses the fusion fuel and sparkplug; the compressed sparkplug becomes critical and undergoes a fission chain reaction, further heating the compressed fusion fuel to a high enough temperature to induce fusion, and also supplying neutrons that react with lithium to create tritium for fusion. Generally, increasing the kinetic energy of gas molecules contained in a limited volume will increase both temperature and pressure (see gas laws). This articles outlines the historical development of the laws describing ideal gases
3. The fusion fuel of the secondary stage may be surrounded by depleted uranium or natural uranium, whose U-238 is not fissile and cannot sustain a chain reaction, but which is fissionable when bombarded by the high-energy neutrons released by fusion in the secondary stage. Depleted uranium (DU is Uranium primarily composed of the Isotope Uranium-238 (U-238 Natural uranium (NU refers to refined Uranium with the same Isotopic ratio as found in nature In Nuclear engineering, a fissile material is one that is capable of sustaining a Chain reaction of Nuclear fission. In Nuclear engineering, a fissile material is one that is capable of sustaining a Chain reaction of Nuclear fission.

Actual designs of thermonuclear weapons may vary. For example, they may or may not use a boosted primary stage, use different types of fusion fuel, and may surround the fusion fuel with beryllium (or another neutron reflecting material) instead of depleted uranium to prevent further fission from occurring. Beryllium (bəˈrɪliəm is a Chemical element with the symbol Be and Atomic number 4 Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate

The basic idea of the Teller–Ulam configuration is that each "stage" would undergo fission or fusion (or both) and release energy, much of which would be transferred to another stage to trigger it. How exactly the energy is "transported" from the primary to the secondary has been the subject of some disagreement, but is thought to be transmitted through the x-rays which are emitted from the fissioning primary. X-radiation (composed of X-rays) is a form of Electromagnetic radiation. This energy is then used to compress the secondary. There are five proposed theories:

• Neutron pressure from the primary explosion. This was allegedly Ulam's first concept and was abandoned as unworkable.
• Blast wave from the primary explosion. This was allegedly Ulam's second concept and was abandoned as unworkable.
• Radiation pressure exerted by the x-rays. Radiation pressure is the Pressure exerted upon any surface exposed to Electromagnetic radiation. This was the first idea put forth by Howard Morland in the article in The Progressive. Howard Morland is a United States journalist and Activist against Nuclear weapons born in 1942 who in 1979 became famous for apparently discovering the The Progressive is an American monthly magazine of politics and culture with a pronounced leftist perspective
• X-rays creating a plasma in the radiation case's filler (a polystyrene plastic foam). In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound Polystyrene ˌpɒliˈstaɪriːn ( IUPAC Polyphenylethene is an aromatic Polymer made from the aromatic Monomer Styrene This was a second idea put forward by Chuck Hansen and later by Howard Morland.
• Tamper/Pusher ablation. Ablation is defined as the removal of material from the surface of an object by Vaporization, Chipping, or other erosive processes This is currently believed to be the actual mechanism.

Radiation pressure

The radiation pressure exerted by the large quantity of x-ray photons inside the closed casing might be enough to compress the secondary. Radiation pressure is the Pressure exerted upon any surface exposed to Electromagnetic radiation. In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena For two thermonuclear bombs for which the general size and primary characteristics are well understood, the Ivy Mike test bomb and the modern W-80 cruise missile warhead variant of the W-61 design, the radiation pressure was calculated to be 73 million bar (atmospheres) (7. The bar (symbol bar) decibar (symbol dbar) and the millibar (symbol mbar, also mb are units of Pressure. 3 TPa) for the Ivy Mike design and 1,400 million bar (140 TPa) for the W-80. TERA is a shielded Twisted pair connector for use with Category 7 twisted-pair data cables developed by The Siemon Company and standardized in 2003 by ^[6]

Foam plasma pressure

Foam plasma pressure is the concept which Chuck Hansen introduced during the Progressive case, based on research which located declassified documents listing special foams as liner components within the radiation case of thermonuclear weapons.

The sequence of firing the weapon (with the foam) would be as follows:

1. The high explosives surrounding the core of the primary fire, compressing the fissile material into a supercritical state and beginning the fission chain reaction. A critical mass is the smallest amount of Fissile material needed for a sustained Nuclear chain reaction.
2. The fissioning primary emits x-rays at the speed of light, which "reflect" along the inside of the casing, irradiating the polystyrene foam (see below for a note on what "reflection" means in this context).
3. The irradiated foam undergoes a phase transition, becoming a hot plasma, pushing against the tamper of the secondary, compressing it tightly, and beginning the fission reaction in the spark plug. In Thermodynamics, phase transition or phase change is the transformation of a thermodynamic system from one phase to another
4. Pushed from both sides (from the primary and the spark plug), the lithium deuteride fuel is highly compressed and heated to thermonuclear temperatures, and begins a fusion reaction.
5. The fuel undergoing the fusion reaction emits a large flux of neutrons, which irradiates the uranium-238 tamper (or the uranium-238 bomb casing), causing it to undergo a fission reaction, providing about half of the total energy.

This would complete the fission-fusion-fission sequence. Fusion, unlike fission, is relatively "clean"—it releases energy but no harmful radioactive products or large amounts of nuclear fallout. Fission products are the atomic fragments left after a large nucleus fissions. Fallout is the residual radiation hazard from a Nuclear explosion, so named because it "falls out" of the atmosphere into which it is spread during the explosion The fission reactions though, especially the last fission reaction, release a tremendous amount of fission products and fallout. If the last fission stage is omitted, by replacing the uranium tamper with one made of lead, for example, the overall explosive force is reduced by approximately half but the amount of fallout is relatively low. Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly

Foam plasma mechanism firing sequence.
A. Warhead before firing; primary (fission bomb) at top, secondary (fusion fuel) at bottom, all suspended in polystyrene foam.
B. High-explosive fires in primary, compressing plutonium core into supercriticality and beginning a fission reaction.
C. Fission primary emits X-rays which are scattered along the inside of the casing, irradiating the polystyrene foam.
D. Polystyrene foam becomes plasma, compressing secondary, and plutonium sparkplug begins to fission.
E. Compressed and heated, lithium-6 deutheride fuel begins fusion reaction, neutron flux causes tamper to fission. A fireball is starting to form. . .

Current technical criticisms of the foam plasma pressure focus on unclassified analysis from similar high energy physics fields which indicate that the pressure produced by such a plasma would only be a small multiplier of the basic photon pressure within the radiation case, and that the foam materials intrinsically have a very low absorption efficiency of the gamma and x-ray radiation from the primary. Gamma rays (denoted as &gamma) are a form of Electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions Most of the energy produced would be absorbed by the walls of the radiation case, and the tamper around the secondary. Analyzing the effects of that absorbed energy led to the third mechanism: ablation.

Tamper-pusher ablation

The third proposed mechanism is that the primary compression mechanism for the thermonuclear secondary is that the outer layers of the tamper-pusher, or heavy metal casing around the thermonuclear fuel, are heated so much by the x-ray flux from the primary that they ablate away, exploding outwards at such high speed that the rest of the tamper recoils inwards at a tremendous velocity, crushing the fusion fuel and the spark plug. Ablation is defined as the removal of material from the surface of an object by Vaporization, Chipping, or other erosive processes

Ablation mechanism firing sequence.
1. Warhead before firing. The nested spheres at the top are the fission primary; the cylinders below are the fusion secondary device.
2. Fission primary's explosives have detonated and collapsed the primary's fissile pit.
3. The primary's fission reaction has run to completion, and the primary is now at several million degrees and radiating gamma and hard x-rays, heating up the inside of the hohlraum and the shield and secondary's tamper.
4. The primary's reaction is over and it has expanded. The surface of the pusher for the secondary is now so hot that it is also ablating or expanding away, pushing the rest of the secondary (tamper, fusion fuel, and fissile spark plug) inwards. The spark plug starts to fission. Not depicted: the radiation case is also ablating and expanding outwards (omitted for clarity of diagram).
5. The secondary's fuel has started the fusion reaction and shortly will burn up. A fireball starts to form.

Rough calculations for the basic ablation effect are relatively simple: the energy from the primary is distributed evenly onto all of the surfaces within the outer radiation case, with the components coming to a thermal equilibrium, and the effects of that thermal energy are then analyzed. The energy is mostly deposited within about one x-ray optical thickness of the tamper/pusher outer surface, and the temperature of that layer can then be calculated. Optical thickness, also called Optical depth, is the depth of a material or medium in which the intensity of Light (or other Radiation) of a The velocity at which the surface then expands outwards is calculated and, from a basic Newtonian momentum balance, the velocity at which the rest of the tamper implodes inwards.

Applying the more detailed form of those calculations to the Ivy Mike device yields vaporized pusher gas expansion velocity of 290 kilometers per second and an implosion velocity of perhaps 400 kilometers per second if 3/4 of the total tamper/pusher mass is ablated off, the most energy efficient proportion. For the W-80 the gas expansion velocity is roughly 410 kilometers per second and the implosion velocity 570 kilometers per second. The pressure due to the ablating material is calculated to be 5. 3 billion bar (530 TPa) in the Ivy Mike device and 64 billion bar (6. TERA is a shielded Twisted pair connector for use with Category 7 twisted-pair data cables developed by The Siemon Company and standardized in 2003 by 4 PPa) in the W-80 device. In Physics and Mathematics, peta- (symbol P) is a prefix in the SI ( System of units) denoting 1015 ^[6]

Comparing the implosion mechanisms

Comparing the three mechanisms proposed, it can be seen that:

• Radiation pressure:
  • Ivy Mike: 73 million bar (7. 3 TPa)
  • W-80: 1. 4 billion bar (140 TPa)
• Plasma pressure:
  • Ivy Mike: (est. ) 350 million bar (35 TPa)
  • W-80: (est. ) 7. 5 billion bar (750 TPa)
• Ablation pressure:
  • Ivy Mike: 5. 3 billion bar (530 TPa)
  • W-80: 64 billion bar (6400 TPa)

The calculated ablation pressure is one order of magnitude greater than the higher proposed plasma pressures and nearly two orders of magnitude greater than calculated radiation pressure. No mechanism to avoid the absorption of energy into the radiation case wall and the secondary tamper has been suggested, making ablation apparently unavoidable. The other mechanisms appear to be unneeded.

United States Department of Defense official declassification reports indicate that foamed plastic materials are or may be used in radiation case liners, and despite the low direct plasma pressure they may be of use in delaying the ablation until energy has distributed evenly and a sufficient fraction has reached the secondary's tamper/pusher. The United States Department of Defense ( DOD or DoD) is the federal department charged with coordinating and supervising all agencies and functions of the government ^[7]

Proposed design variations

A number of possible variations to the weapon design have been proposed:

• Either the tamper or the casing have been proposed as being made of uranium-238 for the final fission stage.
• In some descriptions, additional internal structures exist to protect the secondary from receiving excessive neutrons from the primary.
• The inside of the casing may or may not be specially machined to "reflect" the x-rays. X-ray "reflection" is not like light reflecting off of a mirror, but rather the reflector material is heated by the x-rays, causing the material itself to emit x-rays, which then travel to the secondary. A mirror is an object with a surface that has good Specular reflection; that is it is smooth enough to form an Image.

Two special variations exist which will be discussed in a further section: the cryogenically cooled liquid deuterium device used for the Ivy Mike test, and the putative design of the W88 nuclear warhead — a small, MIRVed version of the Teller–Ulam configuration with a prolate (egg or watermelon shaped) primary and an elliptical secondary. Cryogenics is often used incorrectly to refer to Cryonics, cryopreserving humans or animals Ivy Mike was the codename given to the first US test of a fusion device where a major part of the explosive yield came from fusion The W88 is a United States thermonuclear warhead, with an estimated yield of 475 Kiloton (kt and is small enough to fit on MIRVed missiles A multiple independently targetable reentry vehicle ( MIRV) is a collection of Nuclear weapons carried on a single Intercontinental ballistic missile Equation A spheroid centered at the origin and rotated about the z axis is defined by the implicit equation \left(\frac{x}{a}\right^2+\left(\frac{y}{a}\right^2+\left(\frac{z}{b}\right^2 In geometry an oval or ovoid (from Latin ovum, 'egg' is any Curve resembling an egg or an Ellipse. Watermelon ( Citrullus lanatus ( Thunb) Matsum & Nakai family Cucurbitaceae) refers to both Fruit and Plant of a vine-like (climber Most bombs do not apparently have tertiary stages — the U. S. is only thought to have produced one such model, the massive 25 Mt B41 nuclear bomb,^[8] and the Soviet Union is thought to have used multiple stages in their 50 megaton Tsar Bomba. The B41 was a Thermonuclear weapon deployed by the United States Strategic Air Command in the early 1960s The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 Tsar Bomba (ru Царь-бомба literally " King Bomb" is the Western name for the RDS-220 hydrogen bomb (codenamed "Иван" (Ivan by its If any hydrogen bombs have been made from configurations other than those based on the Teller–Ulam design, the fact of it is not publicly known, with the possible exception of the Sloika design discussed below.

In essence, the Teller–Ulam configuration relies on at least two instances of implosion occurring: first, the conventional (chemical) explosives in the primary would compress the fissile core, resulting in a fission explosion many times more powerful than that which chemical explosives could achieve alone. Second, the radiation from the fissioning of the primary would be used to compress and ignite the secondary, resulting in a fusion explosion many times more powerful than the fission explosion alone. This chain of compression could then be continued with an arbitrary number of secondaries, and would end with the fissioning of the natural uranium tamper, something which could not normally be achieved without the neutron flux provided by the fusion reactions in the secondary. Neutron flux is a term referring to the number of Neutrons passing through an Area over a span of Time. Such a design can be scaled up to an arbitrary strength, potentially to the level of a doomsday device, though usually such weapons are not more than a dozen megatons, which is generally considered enough to destroy even the largest practical targets. A doomsday device is a hypothetical construction &mdash usually a weapon &mdash which could destroy all life on the Earth, or destroy the Earth itself (bringing "

History

Main article: History of the Teller–Ulam design

American developments

The idea of a thermonuclear fusion bomb ignited by a smaller fission bomb was first proposed by Enrico Fermi to his colleague Edward Teller in 1941 at the start of what would become the Manhattan project. This article chronicles the history and origins of the Teller-Ulam design, the technical concept behind modern thermonuclear weapons, also known as the Edward Teller (original Hungarian name Teller Ede) (January 15 1908 &ndash September 9 2003 was a Hungarian -American theoretical Physicist The World War II Manhattan Project developed the first Nuclear weapon (atomic bomb Teller spent most of the Manhattan Project attempting to figure out how to make the design work, to some degree neglecting his assigned work on the Manhattan Project fission bomb program. His difficult and devil's advocate attitude in discussions led Oppenheimer to sidetrack him and other "problem" physicists into the super program to smooth his way.

Stanisław Ulam, a coworker of Teller's, made the first key conceptual leaps towards a workable fusion design. Stanisław Marcin Ulam ( April 13, 1909 &ndash May 13, 1984) was a Polish Mathematician who participated in the Manhattan Ulam's two innovations which rendered the fusion bomb practical were that compression of the thermonuclear fuel before extreme heating was a practical path towards the conditions needed for fusion, and the idea of staging or placing a separate thermonuclear component outside a fission primary component, and somehow using the primary to compress the secondary. Teller then realized that the gamma and X-ray radiation produced in the primary could transfer enough energy into the secondary to create a successful implosion and fusion burn, if the whole assembly was wrapped in a hohlraum or radiation case. Teller and his various proponents and detractors later disputed the degree to which Ulam had contributed to the theories underlying this mechanism.

The "George" shot of Operation Greenhouse in 1951 tested the basic concept for the first time on a very small scale, raising expectations to a near certainty that the concept would work. Operation Greenhouse was the fifth American nuclear test series the second conducted in 1951 and the first to test principles that would lead to developing thermonuclear weapons

In November 1, 1952, the Teller–Ulam configuration was tested at full scale in the "Ivy Mike" shot at an island in the Enewetak atoll, with a yield of 10. Events 996 - Emperor Otto III issues a deed to Gottschalk Bishop of Freising which is the oldest known document using the name Ostarrîchi Year 1952 ( MCMLII) was a Leap year starting on Tuesday (link will display full calendar of the Gregorian calendar. Ivy Mike was the codename given to the first US test of a fusion device where a major part of the explosive yield came from fusion Enewetak (or Eniwetok) is an Atoll in the Marshall Islands of the central Pacific Ocean. 4 megatons (over 450 times more powerful than the bomb dropped on Nagasaki during World War II). The device, dubbed the Sausage, used an extra-large fission bomb as a "trigger" and liquid deuterium—kept in its liquid state by 20 short tons (18 metric tons) of cryogenic equipment—as its fusion fuel, and weighed around 80 short tons (70 metric tons) altogether. Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth The short ton ( S/T) is a unit of mass equal to 2000 lb (around 907 This article is about the tonne or metric ton For other tons see Ton. Cryogenics is often used incorrectly to refer to Cryonics, cryopreserving humans or animals

A photograph of Operation Castle thermonuclear test, Castle Romeo shot. Operation Castle was a United States series of high-energy (high- yield) Nuclear tests by Joint Task Force SEVEN (JTF-7 at Bikini Atoll beginning Castle Romeo was the code name given to one of the tests in the Operation Castle series of American nuclear tests.

The liquid deuterium fuel of Ivy Mike was impractical for a deployable weapon, and the next advance was to use a solid lithium deuteride fusion fuel instead. Lithium hydride ( Li[[Hydride H]] is the compound of Lithium and hydrogen In 1954 this was tested in the "Castle Bravo" shot (the device was code-named the Shrimp), which had a yield of 15 megatons (2. Castle Bravo was the Code name given to the first US test of a so-called dry fuel thermonuclear Hydrogen bomb device detonated on March 1, 5 times higher than expected) and is the largest U. S. bomb ever tested.

Efforts in the United States soon shifted towards developing miniaturized Teller–Ulam weapons which could easily outfit Intercontinental Ballistic Missiles and Submarine Launched Ballistic Missiles. Submarine-launched ballistic missiles or SLBM s are Ballistic missiles delivering Nuclear weapons that are launched from Submarines Modern variants By 1960, with the W47 warhead^[9] deployed on Polaris submarines, megaton-class warheads were as small as 18 inches (0. The W47 was an American thermonuclear warhead used on the Polaris A-1 sub-launched ballistic missile system 5 m) in diameter and around 700 pounds (320 kg) in weight. It was later found in live testing that the Polaris warhead did not work reliably and had to be redesigned. Further innovation in miniaturizing warheads was accomplished by the mid-1970s, when versions of the Teller–Ulam design were created which could fit ten or more warheads on the end of a small MIRVed missile (see the section on the W88 below). A multiple independently targetable reentry vehicle ( MIRV) is a collection of Nuclear weapons carried on a single Intercontinental ballistic missile ^[3]

Soviet developments

Mushroom cloud from the Soviet 50-megaton Tsar Bomba, the largest weapon ever detonated (1961)

The first Soviet fusion design, developed by Andrei Sakharov and Vitaly Ginzburg in 1949 (before the Soviets had a working fission bomb), was dubbed the Sloika, after a Russian layer cake, and was not of the Teller–Ulam configuration. Tsar Bomba (ru Царь-бомба literally " King Bomb" is the Western name for the RDS-220 hydrogen bomb (codenamed "Иван" (Ivan by its Andrei Dmitrievich Sakharov (Андре́й Дми́триевич Са́харов (May 21 1921 – December 14 1989 was an eminent Soviet nuclear Physicist Vitaly Lazarevich Ginzburg (Виталий Лазаревич Гинзбург born October 4 1916 in Moscow) is a Russian theoretical physicist A layer cake is a Cake consisting of multiple layers usually held together by frosting or another type of filling It used alternating layers of fissile material and lithium deuteride fusion fuel spiked with tritium (this was later dubbed Sakharov's "First Idea"). Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. Though nuclear fusion was technically achieved, it did not have the scaling property of a "staged" weapon. The fusion layer wrapped around the fission core could only moderately multiply the fission energy (modern Teller–Ulam designs can multiply it 30-fold). Additionally, the whole fusion stage had to be imploded by conventional explosives, along with the fission core, multiplying the bulk of chemical explosives needed substantially.

Their first Sloika design test, Joe-4, was detonated in 1953 with a yield equivalent to 400 kilotons of TNT (only 15%–20% from fusion). Joe 4 (Warhead name RDS-6s ( Reaktivnyi Dvigatel Stalina; Stalin's Reaction Engine was an American nickname for the first Soviet test of a Thermonuclear Attempts to use a Sloika design to achieve megaton-range results proved unfeasible. After the U. S. tested the "Ivy Mike" device in 1952, proving that a multimegaton bomb could be created, the Soviets searched for an additional design. The "Second Idea", as Sakharov referred to it in his memoirs, was a previous proposal by Ginzburg in November 1948 to use lithium deuteride in the bomb, which would, in the course of being bombarded by neutrons, produce tritium. Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. ^[10] In late 1953 physicist Viktor Davidenko achieved the first breakthrough, that of keeping the primary and secondary parts of the bombs in separate pieces ("staging"). The next breakthrough was discovered and developed by Sakharov and Yakov Zel'dovich, that of using the X-rays from the fission bomb to compress the secondary before fusion ("radiation implosion"), in the spring of 1954. Yakov Borisovich Zel'dovich (Яков Борисович Зельдович ( March 8, 1914 &ndash December 2, 1987) was a prolific Soviet X-radiation (composed of X-rays) is a form of Electromagnetic radiation. Sakharov's "Third Idea", as the Teller–Ulam design was known in the USSR, was tested in the shot "RDS-37" in November 1955 with a yield of 1. RDS-37 was the Soviet Union's first "true" (staged Hydrogen bomb, first tested on November 22, 1955. 6 Mt.

The Soviets demonstrated the power of the "staging" concept in October 1961, when they detonated the massive and unwieldy Tsar Bomba, a 50 Mt hydrogen bomb which derived almost 97% of its energy from fusion. Tsar Bomba (ru Царь-бомба literally " King Bomb" is the Western name for the RDS-220 hydrogen bomb (codenamed "Иван" (Ivan by its It was the largest nuclear weapon developed and tested by any country, but was far too large for the Soviets to use as a weapon.

British developments

In 1954 work began at Aldermaston to develop the British fusion bomb, with Sir William Penney in charge of the project. For the World War II use of this facility see RAF Aldermaston The Atomic Weapons Establishment ( AWE) is responsible for the William George Penney Baron Penney OM, KBE ( 24 June 1909 &ndash 3 March 1991) was a British Physicist British knowledge on how to make a thermonuclear fusion bomb was rudimentary, and at the time the United States was not exchanging any nuclear knowledge because of the Atomic Energy Act of 1946. The Atomic Energy Act of 1946, informally known as the McMahon Act, determined how the United States government would control and manage the Nuclear technology However, the British were allowed to observe the American Castle tests and used sampling aircraft in the mushroom clouds, providing them with clear, direct evidence of the compression produced in the secondary stages by radiation implosion. Operation Castle was a United States series of high-energy (high- yield) Nuclear tests by Joint Task Force SEVEN (JTF-7 at Bikini Atoll beginning

Because of these difficulties, in 1955 British prime minister Anthony Eden agreed to a secret plan, whereby if the Aldermaston scientists failed or were greatly delayed in developing the fusion bomb, it would be replaced by an extremely large fission bomb. Robert Anthony Eden 1st Earl of Avon, KG, MC, PC (12 June 1897 &ndash 14 January 1977 was a British Conservative Politician

In 1957 the Operation Grapple tests were carried out. Operation Grapple, and operations Grapple X, Grapple Y and Grapple Z, were the names of British nuclear tests The first test, Green Granite was a prototype fusion bomb, but failed to produce equivalent yields compared to the Americans and Soviets, only achieving approximately 300 kilotons. The second test Orange Herald was the modified fission bomb and produced 700 kilotons—making it the largest fission explosion ever. At the time almost everyone (including the pilots of the plane that dropped it) thought that this was a fusion bomb. This bomb was put into service in 1958. A second prototype fusion bomb Purple Granite was used in the third test, but only produced approximately 150 kilotons.

A second set of tests was scheduled, with testing recommencing in September 1957. The first test was based on a "… new simpler design. A two stage thermonuclear bomb which had a much more powerful trigger". This test Grapple X Round C was exploded on November 8 and yielded approximately 1. Events 1519 - Hernán Cortés enters Tenochtitlán and Aztec ruler Moctezuma welcomes him with great a Celebration 8 megatons. On April 28, 1958 a bomb was dropped that yielded 3 megatons —Britain's most powerful test. Events 1192 - Assassination of Conrad of Montferrat (Conrad I King of Jerusalem, in Tyre, two days after his title Two final air burst tests on September 2 and September 11, 1958, dropped smaller bombs that yielded around 1 megaton each. Events 44 BC - Pharaoh Cleopatra VII of Egypt declares her son co-ruler as Ptolemy XV Caesarion. Events 9 - The Battle of the Teutoburg Forest ends 506 - The Bishops of Visigothic Gaul Year 1958 ( MCMLVIII) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar.

American observers had been invited to these kinds of tests. After their successful detonation of a megaton-range device (and thus demonstrating their practical understanding of the Teller–Ulam design "secret"), the United States agreed to exchange some of their nuclear designs with Great Britain, leading to the 1958 US-UK Mutual Defence Agreement. The 1958 US-UK Mutual Defence Agreement is a bilateral Treaty between the United States and the United Kingdom on Nuclear weapons cooperation Instead of continuing with their own design, the British were given access to the design of the smaller American Mk 28 warhead and were able to manufacture copies.

Other countries

The People's Republic of China developed their first Teller–Ulam device only 32 months after their first fission test, the shortest fission-to-fusion development time yet known. Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES

The details of the development of the Teller–Ulam design in other countries are less well known.

China

Main article: China and weapons of mass destruction

The People's Republic of China detonated its first device using a Teller–Ulam design June 1967 ("Test No. 6"), a mere 32 months after detonating its first fission weapon (the shortest fission-to-fusion development yet known), with a yield of 3. Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES Chinese nuclear test No 6 was the sixth Chinese nuclear weapons test, detonated on 17 June, 1967. 31 Mt. Little is known about the Chinese thermonuclear program.

France

Main article: France and weapons of mass destruction

Very little is known about the French development of the Teller–Ulam design beyond the fact that they detonated a 2. France is one of the five "Nuclear Weapons States" under the Nuclear Non-Proliferation Treaty but is not known to possess or develop any chemical or This article is about the country For a topic outline on this subject see List of basic France topics. 6 Mt device in the "Canopus" test in August 1968. Canopus (also Opération Canopus in French) was the code name for France's first two-stage

India

Main article: India and weapons of mass destruction

India's first Nuclear test occurred on May 18, 1974 then on May 11, 1998, India detonated a hydrogen bomb in its Operation Shakti tests ("Shakti 1", specifically), though seismographic readings have led many non-Indian experts to conclude that this is unlikely, or at least it was unlikely to have been a success as claimed, because of its low yield (claimed to be around 45 kt, though outside experts estimate it at around 30 kt, both extremely low for a successful thermonuclear detonation). India is believed to possess an arsenal of Nuclear weapons and maintains intermediate-range Ballistic missiles to deliver them Year 1998 ( MCMXCVIII) was a Common year starting on Thursday (link will display full 1998 Gregorian calendar) India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country Pokharan-II refers to test explosions of five Nuclear devices three on 11 May and two on 13 May 1998 conducted by India Pokharan-II refers to test explosions of five Nuclear devices three on 11 May and two on 13 May 1998 conducted by India Seismometers (from Greek Seism - "the shakes" - and Metro - "I measure" are instruments that measure and record motions of the ground including ^[11] However, even low-yield tests can have a bearing on thermonuclear capability, as they can provide information on the behavior of primaries without the full ignition of secondaries. ^[12] a Indian sources have disputed this interpretation. They have repeated early reports and their own analysis including a US Geological Survey report from shortly after the Shakti tests, using seismic data from 125 IRIS stations across the world. They argue that the magnitudes suggested a combined yield of up to 60 kilotonnes, consistent with the Indian announced total yield of 56 kilotonnes. The confirmation about the near 60 kilotonne yield was also carried by the reputed New Scientist Magazine^[13][14] and London-based scientific journal Trust & Verify. ^[15]

Israel

Main article: Israel and weapons of mass destruction

Israel is alleged to possess thermonuclear weapons of the Teller-Ulam design, but is not known to have tested any. Israel is widely believed to possess a substantial arsenal (an estimated 100 to 200 of Nuclear weapons and maintains intercontinental-range Ballistic missiles to deliver

Pakistan

Main article: Pakistan and weapons of mass destruction

Pakistan's nuclear tests were relatively low yield and do not appear to have included a thermonuclear weapon. The Islamic Republic of Pakistan began focusing on nuclear development in January 1972 under the leadership of Prime Minister Zulfiqar Ali

North Korea

Main article: North Korea and weapons of mass destruction

North Korea's single nuclear test was relatively low yield and does not appear to have been of a thermonuclear weapon design. North Korea claims to possess Nuclear weapons and the CIA asserts that it has a substantial arsenal of Chemical weapons.

Public knowledge

The Teller–Ulam design was for many years considered one of the top nuclear secrets, and even today it is not discussed in any detail by official publications with origins "behind the fence" of classification. United States Department of Energy (DOE) policy has been, and continues to be, that they do not acknowledge when "leaks" occur, because doing so would acknowledge the accuracy of the supposed leaked information. The United States Department of Energy ( DOE) is a Cabinet -level department of the United States government responsible for energy policy

Photographs of warhead casings, such as this one of the W80 nuclear warhead, allow for some speculation as to the relative size and shapes of the primaries and secondaries in U. The W80 is a small Thermonuclear warhead (fusion weapon in the nuclear stockpile of the USA with an adjustable explosive yield of between 5 and 150 S. thermonuclear weapons.

Aside from images of the warhead casing (but never of the "physics package" itself), most information in the public domain about this design is regulated to a few terse statements by the DOE and the work of a few individual investigators. Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate

Below is a short discussion of the events which lead to the formation of these "public" models of the Teller–Ulam design, with some discussions as to their differences and disagreements with those principles outlined above.

DOE statements

In 1972 the DOE declassified a statement that "The fact that in thermonuclear (TN) weapons, a fission 'primary' is used to trigger a TN reaction in thermonuclear fuel referred to as a 'secondary'", and in 1979 added, "The fact that, in thermonuclear weapons, radiation from a fission explosive can be contained and used to transfer energy to compress and ignite a physically separate component containing thermonuclear fuel. " To this latter sentence they specified that "Any elaboration of this statement will be classified. "^[16] The only statement which may pertain to the spark plug was declassified in 1991: "Fact that fissile and/or fissionable materials are present in some secondaries, material unidentified, location unspecified, use unspecified, and weapons undesignated. " In 1998 the DOE declassified the statement that "The fact that materials may be present in channels and the term 'channel filler,' with no elaboration", which may refer to the polystyrene foam (or an analogous substance). ^[17]

Whether these statements vindicate some or all of the models presented above is up for interpretation, and official U. S. government releases about the technical details of nuclear weapons have been purposely equivocating in the past (see, i. e. , Smyth Report). The Smyth Report was the common name given to an administrative history written by physicist Henry DeWolf Smyth about the Allied World War II Other information, such as the types of fuel used in some of the early weapons, has been declassified, though of course precise technical information has not been.

The Progressive case

Most of what is known to the public today about the Teller–Ulam design comes from a 1979 magazine article. This edition is available online.

Most of the current ideas on the workings of the Teller–Ulam design came into public awareness after the DOE attempted to censor a magazine article by U. Prior restraint is a Legal term referring to a Government 's actions that prevent materials from being published S. antiweapons activist Howard Morland in 1979 on the "secret of the hydrogen bomb". Howard Morland is a United States journalist and Activist against Nuclear weapons born in 1942 who in 1979 became famous for apparently discovering the In 1978 Morland had decided that discovering and exposing this "last remaining secret" would focus attention onto the arms race and allow citizens to feel empowered to question official statements on the importance of nuclear weapons and nuclear secrecy. The term arms race, in its original usage describes a competition between two or more parties for real or apparent military supremacy Most of Morland's ideas about how the weapon worked were compiled from highly accessible sources—the drawings which most inspired his approach came from none other than the Encyclopedia Americana. The Encyclopædia Americana is one of the largest general Encyclopedias in the English language. Morland also interviewed (often informally) many former Los Alamos scientists (including Teller and Ulam, though neither gave him any useful information), and used a variety of interpersonal strategies to encourage informational responses from them (i. Los Alamos National Laboratory (LANL (previously known at various times as Site Y, Los Alamos Laboratory, and Los Alamos Scientific Laboratory) is a Social engineering is the art of manipulating people into performing actions or divulging confidential information e. , asking questions such as "Do they still use spark plugs?" even if he was not aware what the latter term specifically referred to). ^[18]

Morland eventually concluded that the "secret" was that the primary and secondary were kept separate and that radiation pressure from the primary compressed the secondary before igniting it. Radiation pressure is the Pressure exerted upon any surface exposed to Electromagnetic radiation. When an early draft of the article, to be published in The Progressive magazine, was sent to the DOE after falling into the hands of a professor who was opposed to Morland's goal, the DOE requested that the article not be published, and pressed for a temporary injunction. The Progressive is an American monthly magazine of politics and culture with a pronounced leftist perspective The DOE argued that Morland's information was (1) likely derived from classified sources, (2) if not derived from classified sources, itself counted as "secret" information under the "born secret" clause of the 1954 Atomic Energy Act, and (3) was dangerous and would encourage nuclear proliferation. " Born secret " and " born classified " are both terms which refer to a policy of information being classified from the moment of its inception usually Nuclear proliferation is a term now used to describe the spread of Nuclear weapons, fissile material and weapons-applicable nuclear technology and information to nations

Morland and his lawyers disagreed on all points, but the injunction was granted, as the judge in the case felt that it was safer to grant the injunction and allow Morland, et al. , to appeal, which they did in United States v. The Progressive, et al. (1979). United States of America v Progressive Inc Erwin Knoll Samuel Day Jr

Through a variety of more complicated circumstances, the DOE case began to wane as it became clear that some of the data they were attempting to claim as "secret" had been published in a students' encyclopedia a few years earlier. After another H-bomb speculator, Chuck Hansen, had his own ideas about the "secret" (quite different from Morland's) published in a Wisconsin newspaper, the DOE claimed The Progressive case was moot, dropped their suit and allowed the magazine to publish, which it did in November 1979. Morland had by then, however, changed his opinion of how the bomb worked, suggesting that a foam medium (the polystyrene) rather than radiation pressure was used to compress the secondary, and that in the secondary was a spark plug of fissile material as well. He published these changes, based in part on the proceedings of the appeals trial, as a short erratum in The Progressive a month later. ^[19] In 1981 Morland published a book about his experience, describing in detail the train of thought which led him to his conclusions about the "secret". ^[18][20]

Because the DOE sought to censor Morland's work — one of the few times they violated their usual approach of not acknowledging "secret" material which had been released — it is interpreted as being at least partially correct, though to what degree it lacks information or has incorrect information is not known with any great confidence. The difficulty which a number of nations had in developing the Teller–Ulam design (even when they apparently understood the design, such as with the United Kingdom), makes it somewhat unlikely that this simple information alone is what provides the ability to manufacture thermonuclear weapons. Nevertheless, the ideas put forward by Morland in 1979 have been the basis for all current speculation on the Teller–Ulam design.

Variations

There have been a few variations of the Teller–Ulam design suggested by sources claiming to have information from inside of the fence of classification. Whether these are simply different versions of the Teller–Ulam design, or should be understood as contradicting the above descriptions, is up for interpretation.

Richard Rhodes' "Ivy Mike" device in Dark Sun

In his 1995 book Dark Sun: The Making of the Hydrogen Bomb, author Richard Rhodes describes in detail the internal components of the "Ivy Mike" Sausage device, based on information obtained from extensive interviews with the scientists and engineers who assembled it. Richard Lee Rhodes (b July 4, 1937) is an American journalist historian and author of both fiction and non-fiction (which he prefers to call "verity" Ivy Mike was the codename given to the first US test of a fusion device where a major part of the explosive yield came from fusion According to Rhodes, though there was polystyrene in the "Mike" device, it was not used as a plasma source — the radiation from the primary itself was enough to compress the secondary. Whether or not this would apply only to the "Mike" device, or the Teller–Ulam design in general, is not known, and potentially casts some doubt onto the role of the foam, and to the exact mechanism of radiation "transport". ^[21]

W88 revelations

In 1999, information came out implying that in some U. S. designs, the primary (top) is prolate, while the secondary (bottom) is spherical.

In 1999 a reporter for the San Jose Mercury News reported that the U. The San Jose Mercury News is the major daily Newspaper in San Jose California and Silicon Valley. S. W88 nuclear warhead, a small MIRVed warhead used on the Trident II SLBM, had a prolate (egg or watermelon shaped) primary (code-named Komodo) and a spherical secondary (code-named Cursa) inside a specially shaped radiation case (known as the "peanut" for its shape). The W88 is a United States thermonuclear warhead, with an estimated yield of 475 Kiloton (kt and is small enough to fit on MIRVed missiles A multiple independently targetable reentry vehicle ( MIRV) is a collection of Nuclear weapons carried on a single Intercontinental ballistic missile This article contains technical information about the Trident ballistic missile Submarine-launched ballistic missiles or SLBM s are Ballistic missiles delivering Nuclear weapons that are launched from Submarines Modern variants Equation A spheroid centered at the origin and rotated about the z axis is defined by the implicit equation \left(\frac{x}{a}\right^2+\left(\frac{y}{a}\right^2+\left(\frac{z}{b}\right^2 In geometry an oval or ovoid (from Latin ovum, 'egg' is any Curve resembling an egg or an Ellipse. Watermelon ( Citrullus lanatus ( Thunb) Matsum & Nakai family Cucurbitaceae) refers to both Fruit and Plant of a vine-like (climber A story four months later in The New York Times by William Broad reported that in 1995, a supposed double agent from the People's Republic of China delivered information indicating that China knew these details about the W88 warhead as well, supposedly through espionage. A split album featuring performances by bands The KGB and Alien Spy that was produced in 1997 Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES (This line of investigation eventually resulted in the abortive trial of Wen Ho Lee. Wen Ho Lee ( born December 21, 1939) is a Taiwanese -born American scientist who worked for the University of California at the ) If these stories are true, it would indicate a variation of the Teller–Ulam design which would allow for the miniaturization required for small MIRVed warheads. ^[22][23][24]

The value of a prolate primary lies apparently in the fact that a MIRV warhead is limited by the diameter of the primary—if a prolate primary can be made to work properly, then the MIRV warhead can be made considerably smaller yet still deliver a high-yield explosion—a W88 warhead manages to yield up 475 kt with a physics package 1. Nuclear weapon designs are physical chemical and engineering arrangements that cause the physics package of a nuclear weapon to detonate 75 m (69 in) long, with a maximum diameter of 0. 55 m (22 in), and weighing probably less than 800 lb (360 kg). ^[25] Smaller warheads can allow more of them to fit onto a single missile, as well as improve speed and range.

The calculations for a nonspherical primary are apparently orders of magnitude harder than for a spherical primary, which would likely be of interest to an existing nuclear power like the People's Republic of China (particularly as they no longer conduct nuclear testing, which would yield invaluable design information). Nuclear weapons tests are experiments carried out to determine the effectiveness yield and explosive capability of Nuclear weapons Throughout the twentieth century most nations ^[26]

References

Basic principles

History

Analyzing fallout

External links

Principles

• "Hydrogen bomb / Fusion weapons" at GlobalSecurity. org (see also links on right)
• "Basic Principles of Staged Radiation Implosion (Teller–Ulam)" from Carey Sublette's NuclearWeaponArchive. org.
• "Matter, Energy, and Radiation Hydrodynamics" from Carey Sublette's Nuclear Weapons FAQ.
• "Engineering and Design of Nuclear Weapons" from Carey Sublette's Nuclear Weapons FAQ.
• "Elements of Thermonuclear Weapon Design" from Carey Sublette's Nuclear Weapons FAQ.
• Annotated bibliography for nuclear weapons design from the Alsos Digital Library for Nuclear Issues

History

• PBS: Race for the Superbomb: Interviews and Transcripts (with U. S. and USSR bomb designers as well as historians).
• Howard Morland on how he discovered the "H-bomb secret" (includes many slides).
• The Progressive November 1979 issue – "The H-Bomb Secret: How we got it, why we're telling" (entire issue online).
• Annotated bibliography on the hydrogen bomb from the Alsos Digital Library
• University of Southampton, Mountbatten Centre for International Studies, Nuclear History Working Paper No5.