116 Sentences With "fission bomb" | Random Sentence Generator

"Even a boosted fission bomb produces a yield bigger than this, so we don't think this is a successful test of a boosted fission bomb either," he added.

More likely a "boosted" weapon with tritium added to increase the yield of a fission bomb.

Berg's assignment is to determine whether the scientist is making a fission bomb for the Nazis.

This involves a very small amount of fusion to boost the explosive capability of a fission bomb.

This involves a very small amount of fusion to "boost" the explosive capability of a fission bomb.

In an H-bomb, conventional explosives compress and detonate a conventional fission bomb, triggering a powerful secondary fusion device.

The hydrogen bomb uses a two step process: a fission bomb acts like a trigger, creating enough energy to create fusion that releases substantially more energy than fission alone.

Joe Cirincione, a nuclear expert who is president of Ploughshares Fund, a global security organisation, said North Korea may have mixed a hydrogen isotope in a normal atomic fission bomb.

On the other hand, if that blast was a test of a smaller, more efficient boosted fission bomb, then yes, the Unha-3 could have enough capacity to deliver a nuclear warhead.

The process likely used by North Korea, called "boosting," involves an intermediate device that uses a hydrogen isotope to vastly increase the explosive power of an old-fashioned fission bomb, the experts told Reuters.

But some also said that although North Korea did not yet have H-bomb capability, it might be developing and preparing to test a boosted fission bomb, more powerful than a traditional nuclear weapon.

In reality, most experts think the weapon was not the kind of fusion-based city-destroyer we think of when we hear "H-bomb," but rather a less dramatic nuclear weapon, called a boosted fission bomb.

A South Korean Defense Ministry official, who requested anonymity to speak about a national security matter, said Thursday that the ministry believed that even if the device was a boosted fission bomb, the test was probably a failure.

A thermonuclear bomb (also known as a hydrogen bomb) is a more advanced and powerful design, where a fission bomb ignites a second stage of fissionable material to induce a fusion reaction, resulting in a much larger explosion.

Scientists say that explosion detonated with the force of over 470 kilotons of TNT, or nearly as strong as the MK-18 "Ivy King" in 1952, the largest pure-fission bomb ever tested by the U.S. at 500 kilotons.

Hydrogen bombs, also known as thermonuclear weapons, work in two stages: the first detonates a fission bomb to produce energy in sufficient quantities that, when it is then focused on light nuclei, a plasma is created that enables fusion reactions to take place.

To accomplish this, tritium gas is injected into a hollow core inside the either highly enriched uranium or plutonium contained in a standard fission bomb, said Cheryl Rofer, who worked as a chemist on nuclear weapons at the Los Alamos National Laboratory.

He spoke several languages, was incredibly smart and knew how to keep a secret.) He's ordered to fly to Nazi Germany and find out whether the physicist Werner Heisenberg is developing a fission bomb; if so, Berg (played by Paul Rudd) must kill him.

The main aim of the summits has been to create a better system of global safeguards to ensure that nuclear material, specifically highly enriched uranium and plutonium, which could be used by terrorists to construct a so-called "dirty bomb"—or even a fission bomb—does not get into the wrong hands.

There are other types of nuclear weapons as well. For example, a boosted fission weapon is a fission bomb that increases its explosive yield through a small number of fusion reactions, but it is not a fusion bomb. In the boosted bomb, the neutrons produced by the fusion reactions serve primarily to increase the efficiency of the fission bomb. There are two types of boosted fission bomb: internally boosted, in which a deuterium-tritium mixture is injected into the bomb core, and externally boosted, in which concentric shells of lithium-deuteride and depleted uranium are layered on the outside of the fission bomb core.

In the Teller-Ulam design, which accounts for all multi-megaton yield hydrogen bombs, this is accomplished by placing a fission bomb and fusion fuel (tritium, deuterium, or lithium deuteride) in proximity within a special, radiation-reflecting container. When the fission bomb is detonated, gamma rays and X-rays emitted first compress the fusion fuel, then heat it to thermonuclear temperatures. The ensuing fusion reaction creates enormous numbers of high-speed neutrons, which can then induce fission in materials not normally prone to it, such as depleted uranium. Each of these components is known as a "stage", with the fission bomb as the "primary" and the fusion capsule as the "secondary".

Most of the energy released by a fission bomb is in the form of x-rays. The spectrum is approximately that of a black body at a temperature of 50,000,000 kelvins (a little more than three times the temperature of the Sun's core). The amplitude can be modeled as a trapezoidal pulse with a one microsecond rise time, one microsecond plateau, and one microsecond fall time. For a 30 kiloton fission bomb, the total x-ray output would be 100 terajoules.

In a standard thermonuclear design, a small fission bomb is placed close to a larger mass of thermonuclear fuel. The two components are then placed within a thick radiation case, usually made from uranium, lead or steel. The case traps the energy from the fission bomb for a brief period, allowing it to heat and compress the main thermonuclear fuel. The case is normally made of depleted uranium or natural uranium metal, because the thermonuclear reactions give off massive numbers of high-energy neutrons that can cause fission reactions in the casing material.

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. In 1957 the Operation Grapple tests were carried out. The first test, Green Granite was a prototype fusion bomb, but failed to produce equivalent yields compared to the U.S. and Soviets, achieving only approximately 300 kilotons. The second test Orange Herald was the modified fission bomb and produced 720 kilotons—making it the largest fission explosion ever.

The Robin was the common design nuclear fission bomb core for several Cold War designs for American nuclear and thermonuclear weapons, according to researcher Chuck Hansen. Beware the old story by Chuck Hansen, Bulletin of the Atomic Scientists, March/April 2001 pp. 52-55 (vol. 57, no. 02) United States Nuclear Tests July 1945 to 31 December 1992 , NRDC NWD 94-1, Robert Standish Norris and Thomas B. Cochran, accessed Dec 11, 2007 Primary is the technical term for the fission bomb component of a thermonuclear or fusion bomb, which is used to start the reactions going and implode and detonate the second, fusion stage.

For Green Granite, Penney proposed a design based on radiation implosion and staging. There would be three stages, which he called Tom, Dick and Harry. Tom, the primary stage, would be a fission bomb. It would produce radiation to implode a secondary, Dick, another fission device.

Considering the idea of the fission bomb theoretically settled—at least until more experimental data was available—the 1942 Berkeley conference then turned in a different direction. Edward Teller pushed for discussion of a more powerful bomb: the "super", now usually referred to as a "hydrogen bomb", which would use the explosive force of a detonating fission bomb to ignite a nuclear fusion reaction in deuterium and tritium.. Teller proposed scheme after scheme, but Bethe refused each one. The fusion idea was put aside to concentrate on producing fission bombs. Teller also raised the speculative possibility that an atomic bomb might "ignite" the atmosphere because of a hypothetical fusion reaction of nitrogen nuclei.

Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been used twice in war, both times by the United States against Japan near the end of World War II. On August 6, 1945, the U.S. Army Air Forces detonated a uranium gun-type fission bomb nicknamed "Little Boy" over the Japanese city of Hiroshima; three days later, on August 9, the U.S. Army Air Forces detonated a plutonium implosion-type fission bomb nicknamed "Fat Man" over the Japanese city of Nagasaki. These bombings caused injuries that resulted in the deaths of approximately 200,000 civilians and military personnel. The ethics of these bombings and their role in Japan's surrender are subjects of debate.

From 1944-1947 Howland served in the Armed Forces. In 1944 he joined the Manhattan Project of the Corps of Engineers, which had started to develop a fission bomb. He served as medical officer in charge of special problems. This opportunity allowed him to become one of the early authorities on the medical effects of radiation exposure.

The simplest was shooting a "cylindrical plug" into a sphere of "active material" with a "tamper"—dense material that would focus neutrons inward and keep the reacting mass together to increase its efficiency. They also explored designs involving spheroids, a primitive form of "implosion" suggested by Richard C. Tolman, and the possibility of autocatalytic methods, which would increase the efficiency of the bomb as it exploded. Considering the idea of the fission bomb theoretically settled—at least until more experimental data was available—the Berkeley conference then turned in a different direction. Edward Teller pushed for discussion of a more powerful bomb: the "Super", usually referred to today as a "hydrogen bomb", which would use the explosive force of a detonating fission bomb to ignite a nuclear fusion reaction between deuterium and tritium.

Carrier supremacy > destroyed her army and navy air forces. Carrier supremacy destroyed her > fleet. Carrier supremacy gave us bases adjacent to her home islands, and > carrier supremacy finally left her exposed to the most devastating sky > attack – the atomic fission bomb – that man has suffered. > When I say carrier supremacy defeated Japan, I do not mean air power in > itself won the Battle of the Pacific.

He and Bethe developed the Bethe–Feynman formula for calculating the yield of a fission bomb, which built upon previous work by Robert Serber. As a junior physicist, he was not central to the project. He administered the computation group of human computers in the theoretical division. With Stanley Frankel and Nicholas Metropolis, he assisted in establishing a system for using IBM punched cards for computation.

As part of Britain's independent nuclear deterrent, the Vulcan initially carried Britain's first nuclear weapon, the Blue Danube gravity bomb.Darling 2007, p. 6. Blue Danube was a low-kiloton yield fission bomb designed before the United States detonated the first hydrogen bomb. These were supplemented by U.S.-owned Mk 5 bombs (made available under the Project E programme) and later by the British Red Beard tactical nuclear weapon.

Plumbbob John Nuclear Test, a live test of nuclear AIR-2A Genie rocket on July 19th 1957. Fired by a US Air Force F-89J over Yucca Flats Nuclear Test Site at an altitude of . The W25 was a small nuclear warhead developed by the United States Air Force and Los Alamos Scientific Laboratory for air-defense use. It was a fission bomb with a nominal yield of 1.5 kt.

The first fission bomb, codenamed "The Gadget", was detonated during the Trinity Test in the desert of New Mexico on July 16, 1945. Two other fission bombs, codenamed "Little Boy" and "Fat Man", were used in combat against the Japanese cities of Hiroshima and Nagasaki in on August 6 and 9, 1945 respectively. Even the first fission bombs were thousands of times more explosive than a comparable mass of chemical explosive.

It was found in early experimentation that normally most of the neutrons released in the cascading chain reaction of the fission bomb are absorbed by the bomb case. Building a bomb case of materials which transmitted rather than absorbed the neutrons could make the bomb more intensely lethal to humans from prompt neutron radiation. This is one of the features used in the development of the neutron bomb.

The Kremlin's Nuclear Sword: The Rise and Fall of Russia's Strategic Nuclear Forces 1945–2000. Smithsonian Books. . Adding a shell of natural, unenriched uranium around the deuterium would increase the deuterium concentration at the uranium-deuterium boundary and the overall yield of the device, because the natural uranium would capture neutrons and itself fission as part of the thermonuclear reaction. This idea of a layered fission-fusion-fission bomb led Sakharov to call it the sloika, or layered cake.

China tested its first nuclear weapon device ("596") in 1964 at the Lop Nur test site. The weapon was developed as a deterrent against both the United States and the Soviet Union. Two years later, China had a fission bomb capable of being put onto a nuclear missile. It tested its first hydrogen bomb ("Test No. 6") in 1967, a mere 32 months after testing its first nuclear weapon (the shortest fission-to-fusion development known in history).

On August 29, 1949, the effort brought its results, when the USSR successfully tested its first fission bomb, dubbed "Joe-1" by the U.S.Holloway, Stalin and the Bomb, pp. 215–218. The news of the first Soviet bomb was announced to the world first by the United States,Young and Schilling, Super Bomb, p. 21. which had detected atmospheric radioactive traces generated from its test site in the Kazakh Soviet Socialist Republic.Holloway, Stalin and the Bomb, p. 213.

When a fission bomb explodes, it releases X-Rays, which implodes the fusion side. This "secondary," was scaled down to very small size. His earliest work concerned the study of how small a fusion bomb could be made while still having a large "gain" to provide net energy output. This work suggested that at very small sizes, on the order of milligrams, very little energy would be needed to ignite it, much less than a fission "primary".

The U.S. demands the CSA's unconditional surrender: the Confederates refuse and fire two long-range rockets into Philadelphia. U.S. forces drive through the center of the CSA and cut it in half, while a second U.S. force drives through Virginia to capture Richmond, and eventually take it in heavy street fighting. With British aid, the Confederacy produces a fission bomb. Under the commands of Clarence Potter, Confederate troops dressed as their U.S. counterparts smuggle the bomb into Philadelphia and it detonates.

While serving in the United States Army from 1955 to 1956, Mooney was assigned to a series of nuclear tests in the Pacific Ocean at Enewetak Atoll in the Marshall Islands, which included 17 atom bomb and two hydrogen bomb tests. Mooney was as close as 7½ miles from fission bomb tests. Mooney came to Engelhard in 1960, after graduate school, as a result of a connection made in an electrochemical engineering course. He worked at the company's Gas Equipment Division.

The first Soviet atomic device was tested on August 29, 1949. After moving to Sarov in 1950, Sakharov played a key role in the development of the first megaton-range Soviet hydrogen bomb using a design known as Sakharov's Third Idea in Russia and the Teller–Ulam design in the United States. Before his Third Idea, Sakharov tried a "layer cake" of alternating layers of fission and fusion fuel. The results were disappointing, yielding no more than a typical fission bomb.

RDS-6, the first Soviet test of a hydrogen bomb, took place on August 12, 1953, and was nicknamed Joe 4 by the Americans. It used a layer-cake design of fission and fusion fuels (uranium 235 and lithium-6 deuteride) and produced a yield of 400 kilotons. This yield was about ten times more powerful than any previous Soviet test. When developing higher level bombs, the Soviets proceeded with the RDS-6 as their main effort instead of the analog RDS-7 advanced fission bomb.

This was the code name for the British Uranium Committee project which had worked on a theoretical design for an atomic bomb. One significant contribution was a calculation of the critical mass of uranium. The mass was less than earlier estimates and suggested that development of a fission bomb was practical. "Tube Alloys" was part of a shipment of the most secret scientific research in Great Britain that was sent to the United States for safekeeping when the threat of German invasion was significant.

In 1953, shortly after the Americans tested a thermonuclear weapon in 1952, followed by the Soviets with Joe 4, and before the UK government took a decision in July 1954 to develop a thermonuclear weapon, the Atomic Weapons Research Establishment (AWRE) at Aldermaston was asked about the possibilities for a very large pure fission bomb with a yield of one megaton. This studyPublic Record Office, London. AIR 2/13759 E8A. (PRO) referred to the Zodiak Mk.3 bomb, but progressed no further than a rudimentary study.

It still holds the record for the largest fission explosion ever tested (as the Ivy King device tested during Operation Ivy), producing over 500 kilotons of TNT equivalent. Taylor was credited with developing multiple techniques that improved the fission bomb. For example, he was largely responsible for the development of fusion boosting, which is a technique that improves the reaction yield and efficiency of a nuclear reaction. This technique was a re-invention of the implosion mechanism used in the bomb detonated at Nagasaki.

In a Teller-Ulam bomb, the object to be imploded is called the "secondary". It contains fusion material, such as lithium deuteride, and its outer layers are a material which is opaque to x-rays, such as lead or uranium-238. In order to get the x-rays from the surface of the primary, the fission bomb, to the surface of the secondary, a system of "x-ray reflectors" is used. The reflector is typically a cylinder made of a material such as uranium.

This was chalked up to Taylor instability, which limited the compression of the light elements in the core. The bomb was hailed as a hydrogen bomb, and the truth that it was actually a large fission bomb was kept secret by the British government until the end of the Cold War. An Operational Requirement (OR1142) had been issued in 1955 for a thermonuclear warhead for a medium-range ballistic missile, which became Blue Streak. This was revised in November 1955, with "megaton" replacing "thermonuclear".

The suspects reportedly wanted US$ 10 million for the material, which the Security Service determined was produced in Russia during the era of the Soviet Union and smuggled into Ukraine through a neighboring country. In July 2014, ISIS militants seized of uranium compounds from Mosul University. The material was unenriched and so could not be used to build a conventional fission bomb, but a dirty bomb is a theoretical possibility. However, uranium's relatively low radioactivity makes it a poor candidate for use in a dirty bomb.

A number of the different fission bomb assembly methods explored during the summer 1942 conference, later reproduced as drawings in The Los Alamos Primer. In the end, only the "gun" method (at top) and a more complicated variation of the "implosion" design would be used. At the bottom are "autocatalytic method" designs. The Los Alamos Primer was a printed version of the first five lectures on the principles of nuclear weapons given to new arrivals at the top-secret Los Alamos laboratory during the Manhattan Project.

North Korea claims successful hydrogen bomb test in 'self-defence against US' The Guardian, 6 January 2016. However, third-party experts as well as officials and agencies in South Korea questioned North Korea's claims and contend that the device was more likely to have been a fission bomb such as a boosted fission weapon. Such weapons use hydrogen fusion to produce smaller, lighter warheads suitable for arming a delivery device such as a missile, rather than to attain the destructive power of a true hydrogen bomb.

A simplified summary of the above explanation is: # An implosion assembly type of fission bomb explodes. This is the primary stage. If a small amount of deuterium/tritium gas is placed inside the primary's core, it will be compressed during the explosion and a nuclear fusion reaction will occur; the released neutrons from this fusion reaction will induce further fission in the 239Pu or 235U used in the primary stage. The use of fusion fuel to enhance the efficiency of a fission reaction is called boosting.

It was assumed that the uranium gun-type bomb could then be adapted from it. In December 1943 the British mission of 19 scientists arrived in Los Alamos. Hans Bethe became head of the Theoretical Division. The two fission bomb assembly methods. In April 1944 it was found by Emilio Segrè that the plutonium-239 produced by the Hanford reactors had too high a level of background neutron radiation, and underwent spontaneous fission to a very small extent, due to the unexpected presence of plutonium-240 impurities.

Throughout his participation in the Manhattan Project, Teller's efforts had been directed toward the development of a "super" weapon based on nuclear fusion, rather than toward development of a practical fission bomb. After extensive discussion, the participants reached a consensus that his ideas were worthy of further exploration. A few weeks later, Ulam received an offer of a position at Los Alamos from Metropolis and Robert D. Richtmyer, the new head of its theoretical division, at a higher salary, and the Ulams returned to Los Alamos.

This was chalked up to Taylor instability, which limited the compression of the light elements in the core. The bomb was hailed as a hydrogen bomb, and the truth that it was actually a large fission bomb was kept secret by the British government until the end of the Cold War. The third and final shot of the series was Grapple 3, the test of Purple Granite. This was dropped on 19 June by a Valiant XD823 piloted by Steele, with Millett and XD824 as the grandstand aircraft.

The first shot was a test of Pendant, a fission bomb boosted with solid lithium hydride intended as a primary for a thermonuclear bomb. Rather than being dropped from a bomber, this bomb was suspended from a string of four vertically stacked barrage balloons. This was chosen over an air drop because the bomb assembly could not be fitted into a dropable casing, but it introduced a host of problems. A balloon shot had been tried only once before by the British, during Operation Antler at Maralinga in October 1957.

Lewis and his crew, minus their original co-pilot Dick McNamara, were Tibbets' crew for the mission, and it included two specialists for the arming of Little Boy, the uranium-235 fission bomb. The entire story was written by Lewis just before his death in 1983. His log, the only minute-by-minute recording on paper by any crew member that day, is part of his copyrighted historical manuscript. His sons and daughter are in the process of publishing the manuscript before the 75th anniversary of the bombing in 2020.

In 1949, the Soviets exploded their first fission bomb, and in 1950 U.S. President Harry S. Truman ended the H-bomb debate by ordering the Los Alamos designers to build one. In 1952, the 10.4-megaton Ivy Mike explosion was announced as the first hydrogen bomb test, reinforcing the idea that hydrogen bombs are a thousand times more powerful than fission bombs. In 1954, J. Robert Oppenheimer was labeled a hydrogen bomb opponent. The public did not know there were two kinds of hydrogen bomb (neither of which is accurately described as a hydrogen bomb).

As a daughter product of fission bomb testing from the 1950s through the mid-1980s, caesium-137 was released into the atmosphere, where it was absorbed readily into solution. Known year-to-year variation within that period allows correlation with soil and sediment layers. Caesium-134, and to a lesser extent caesium-135, have also been used in hydrology to measure the caesium output by the nuclear power industry. While they are less prevalent than either caesium-133 or caesium-137, these bellwether isotopes are produced solely from anthropogenic sources.

Chemists at the Los Alamos Laboratory developed methods of purifying uranium and plutonium, the latter a metal that only existed in microscopic quantities when Project Y began. Its metallurgists found that plutonium had unexpected properties, but were nonetheless able to cast it into metal spheres. The laboratory built the Water Boiler, an aqueous homogeneous reactor that was the third reactor in the world to become operational. It also researched the Super, a hydrogen bomb that would use a fission bomb to ignite a nuclear fusion reaction in deuterium and tritium.

Mark 7 "Thor" (or Mk-7') was the first tactical fission bomb adopted by US armed forces. It was also the first weapon to be delivered using the toss method with the help of the low-altitude bombing system (LABS). The weapon was tested in Operation Buster-Jangle. To facilitate external carry by fighter- bomber aircraft, Mark 7 was fitted with retractable stabilizer fins. The Mark 7 warhead (W7) also formed the basis of the BOAR rocket, the Mark 90 Betty nuclear depth charge, MGR-1 Honest John rocket, and MGM-5 Corporal ballistic missile.

25 female survivors required extensive post-war surgeries, and were termed the Hiroshima maidens. The Hiroshima Maidens are a group of 25 Japanese women who were school age girls when they were seriously disfigured as a result of the thermal flash of the fission bomb dropped on Hiroshima on the morning of August 6, 1945. They subsequently went on a highly publicized journey to get reconstructive surgery in the US in 1955. Keloid scars from their burns marred their faces and many of their hand burns healed into bent claw-like positions.

There are two parts to a typical hydrogen bomb, a plutonium- based fission bomb known as the primary, and a cylindrical arrangement of fusion fuels known as the secondary. The primary releases significant amounts of x-rays, which are trapped within the bomb casing and heat and compress the secondary until it undergoes ignition. The secondary consists of lithium deuteride fuel, which requires an external neutron source to begin the reaction. This is normally in the form of a small plutonium "spark plug" in the center of the fuel.

The Mark 18 nuclear bomb, also known as the SOB or Super Oralloy Bomb, was an American nuclear bomb design which was the highest yield fission bomb produced by the US. The Mark 18 had a design yield of 500 kilotons. Noted nuclear weapon designer Ted Taylor was the lead designer for the Mark 18. The Ivy King test firing of the Mark 18 SOB design The Mark 18 was tested once, in the Ivy King nuclear test at the Enewetak atoll in the Pacific Ocean. The test was a complete success at full yield.

A total of 150 W59 warheads were produced during its lifetime. The W59 was one of five nuclear weapon designs identified by researcher Chuck Hansen as using the common design Tsetse primary or first fission bomb stage. Hansen's research indicates that the Tsetse primary was used in the US B43 nuclear bomb, W44 nuclear warhead, W50 nuclear warhead, B57 nuclear bomb, and W59. Historical evidence indicates that these weapons shared a reliability problem, which Hansen attributes to miscalculation of the reaction cross section of tritium in fusion reactions.

This would be extremely explosive, a true "atomic bomb." The discovery that plutonium-239 could be produced in a nuclear reactor pointed towards another approach to a fast neutron fission bomb. Both approaches were extremely novel and not yet well understood, and there was considerable scientific skepticism at the idea that they could be developed in a short amount of time. On June 28, 1941, the Office of Scientific Research and Development was formed in the U.S. to mobilize scientific resources and apply the results of research to national defense.

The idea of a thermonuclear fusion bomb ignited by a smaller fission bomb was first proposed by Enrico Fermi to his colleague Edward Teller when they were talking at Columbia University in September 1941,Rhodes, Dark Sun, p. 207. at the start of what would become the Manhattan Project. Teller spent much of the Manhattan Project attempting to figure out how to make the design work, preferring it to work on the atomic bomb, and over the last year of the project was assigned exclusively to the task.Rhodes, Dark Sun, pp. 117, 248.

Gerboise Blanche operation was carried out 3 months after the success of the first test, Gerboise Bleue. Unlike the first attempt and the two others that were to come, this bomb was placed a few kilometres from ground zero, and detonated on a concrete pad. This was a voluntary act of the authorities as they feared the usual test site would have been too contaminated for the next tests. On 1 April 1960 at 6:17:00 UTC, the 1,250 kg plutonium filled fission bomb was detonated with a yield of 3 kt.

Conducted on May 25, 1951, Item was the first test of an actual boosted fission weapon, nearly doubling the normal yield of a similar non-boosted weapon. In this test, deuterium-tritium (D-T) gas was injected into the enriched uranium core of a nuclear fission bomb. The extreme heat of the fissioning bomb produced thermonuclear fusion reactions within the D-T gas. While not enough to be considered a full nuclear fusion bomb, the large number of high-energy neutrons released nearly doubled the efficiency of the nuclear fission reaction.

Only a fraction of the production is used commercially., technetium-99 in the form of ammonium pertechnetate is available to holders of an Oak Ridge National Laboratory permit: Technetium-99 is produced by the nuclear fission of both uranium-235 and plutonium-239. It is therefore present in radioactive waste and in the nuclear fallout of fission bomb explosions. Its decay, measured in becquerels per amount of spent fuel, is the dominant contributor to nuclear waste radioactivity after about 104 to 106 years after the creation of the nuclear waste.

By designing the thermonuclear stage of the weapon carefully, the neutron burst can be maximized while minimizing the blast itself. This makes the lethal radius of the neutron burst greater than that of the explosion itself. Since the neutrons disappear from the environment rapidly, such a burst over an enemy column would kill the crews and leave the area able to be quickly reoccupied. Compared to a pure fission bomb with an identical explosive yield, a neutron bomb would emit about ten times the amount of neutron radiation.

Development of nuclear models (such as the liquid-drop model and nuclear shell model) made prediction of properties of nuclides possible. No existing model of nucleon–nucleon interaction can analytically compute something more complex than based on principles of quantum mechanics, though (note that complete computation of electron shells in atoms is also impossible yet). The most developed branch of nuclear physics in 1940s was studies related to nuclear fission due to its military significance. The main focus of fission-related problems is interaction of atomic nuclei with neutrons: a process that occurs in a fission bomb and a nuclear fission reactor.

This section was removed from later editions, but, according to Glasstone in 1978, not because it was inaccurate or because the weapons had changed. Fission products are as deadly as neutron-activated cobalt. The standard high-fission thermonuclear weapon is automatically a weapon of radiological warfare, as dirty as a cobalt bomb. Initially, gamma radiation from the fission products of an equivalent size fission-fusion- fission bomb are much more intense than Co-60: 15,000 times more intense at 1 hour; 35 times more intense at 1 week; 5 times more intense at 1 month; and about equal at 6 months.

An alert mobilizes jets from the Royal Canadian Air Force, which are unable to shoot it down and are destroyed in the attempt. With the missile projected to fly over New York City, the U.S. military orders a full mobilization. The U.S. and Canadian authorities implement civil defense procedures, preparing the cities of New York and Ottawa for the imminent passage of the missile. As Havenbrook is being evacuated, David realizes that he can use the Jove rocket to get through the missile's intense heat to destroy it, using the fission bomb "trigger" from the incomplete hydrogen warhead.

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. It used alternating layers of fissile material and lithium deuteride fusion fuel spiked with tritium (this was later dubbed Sakharov's "First Idea"). Though nuclear fusion might have been technically achievable, it did not have the scaling property of a "staged" weapon. Thus, such a design could not produce thermonuclear weapons whose explosive yields could be made arbitrarily large (unlike U.S. designs at that time).

A third confinement principle is to apply a rapid pulse of energy to a large part of the surface of a pellet of fusion fuel, causing it to simultaneously "implode" and heat to very high pressure and temperature. If the fuel is dense enough and hot enough, the fusion reaction rate will be high enough to burn a significant fraction of the fuel before it has dissipated. To achieve these extreme conditions, the initially cold fuel must be explosively compressed. Inertial confinement is used in the hydrogen bomb, where the driver is x-rays created by a fission bomb.

Andrei Sakharov's study group at FIAN in 1948 came up with a second concept in which adding a shell of natural, unenriched uranium around the deuterium would increase the deuterium concentration at the uranium-deuterium boundary and the overall yield of the device, because the natural uranium would capture neutrons and itself fission as part of the thermonuclear reaction. This idea of a layered fission-fusion- fission bomb led Sakharov to call it the sloika, or layered cake. It was also known as the RDS-6S, or Second Idea Bomb.The American counterpart to this idea was Edward Teller's Alarm Clock design of August 1946.

In nuclear fusion, the nuclei of light elements are fused to create a heavier element. To review this work and the general theory of fission reactions, Oppenheimer and Fermi convened meetings at the University of Chicago in June and at the University of California in Berkeley, in July with theoretical physicists Hans Bethe, John Van Vleck, Edward Teller, Emil Konopinski, Robert Serber, Stan Frankel, and Eldred C. Nelson, the latter three former students of Oppenheimer, and experimental physicists Emilio Segrè, Felix Bloch, Franco Rasetti, John Manley, and Edwin McMillan. They tentatively confirmed that a fission bomb was theoretically possible. There were still many unknown factors.

In a fission bomb, the fissile fuel is "assembled" quickly by a uniform spherical implosion created with conventional explosives, producing a supercritical mass. In this state, many of the neutrons released by the fissioning of a nucleus will induce fission of other nuclei in the fuel mass, also releasing additional neutrons, leading to a chain reaction. This reaction consumes at most 20% of the fuel before the bomb blows itself apart, or possibly much less if conditions are not ideal: the Little Boy (gun type mechanism) and Fat Man (implosion type mechanism) bombs had efficiencies of 1.38% and 13%, respectively. Fusion boosting is achieved by introducing tritium and deuterium gas.

The bomb was attached underneath the aircraft, which carried the weapon semi-externally since it could not be carried inside a standard Tu-95's bomb-bay, similar to the way the B.1 Special version of the Avro Lancaster did with the ten-tonne Grand Slam "earthquake bomb". Along with the Tsar Bomba, the Tu-95 proved to be a versatile bomber that would deliver the RDS-4 Tatyana (a fission bomb with a yield of forty-two kilotons), RDS-6S thermonuclear bomb, the RDS-37 2.9-megaton thermonuclear bomb, and the RP-30-32 200-kiloton bomb. The early versions of this bomber lacked comfort for their crews.

The Mk-54 weighed about 51 lb (23 kg), with a selectable yield of 10 or 20 tons, which Vialls claimed was consistent with the damage inflicted in Bali and elsewhere. A complete Mk-54 round weighed 76 lb (34.5 kg). One criticism of Vialls' theory was the absence of any radiation in Bali after the explosion. Vialls explained this flaw by arguing that Geiger counters cannot effectively detect alpha radiation, the most likely radiation to be present after the detonation of a plutonium fission bomb, since alpha particles are large and do not penetrate the walls of the Geiger-Muller tubes adequately enough to register radiation.

However the design was seen to be worth pursuing because deuterium is abundant and uranium is scarce, and he had no idea how powerful the US design was. Sakharov realised that in order to cause the explosion of one side of the fuel to symmetrically compress the fusion fuel, a mirror could be used to reflect the radiation. The details had not been officially declassified in Russia when Sakharov was writing his memoirs, but in the Teller–Ulam design, soft X-rays emitted by the fission bomb were focused onto a cylinder of lithium deuteride to compress it symmetrically. This is called radiation implosion.

A nuclear weapon (also called an atom bomb, nuke, atomic bomb, nuclear warhead, A-bomb, or nuclear bomb) is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or from a combination of fission and fusion reactions (thermonuclear bomb). Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent).

The basics of the Teller–Ulam design for a hydrogen bomb: a fission bomb uses radiation to compress and heat a separate section of fusion fuel. The other basic type of nuclear weapon produces a large proportion of its energy in nuclear fusion reactions. Such fusion weapons are generally referred to as thermonuclear weapons or more colloquially as hydrogen bombs (abbreviated as H-bombs), as they rely on fusion reactions between isotopes of hydrogen (deuterium and tritium). All such weapons derive a significant portion of their energy from fission reactions used to "trigger" fusion reactions, and fusion reactions can themselves trigger additional fission reactions.

The technical problem was figuring out a way to get a fusion reaction to initiate and propagate, which required temperatures attainable only with a fission bomb. The hydrodynamic calculations involved were daunting, and ENIAC was used to run a computer simulation of the Super in December 1945 and January 1946. The Polish mathematician Stanislaw Ulam, his wife Francoise Ulam, who performed the calculations, and their collaborator, Cornelius Everett, worked on the Super design through 1949. There was no push from the military for the weapon, because the AEC regarded it as too secret to inform either its own Military Liaison Committee or the Armed Forces Special Weapons Project about it.

The Soviet team had been working on the RDS-6T concept, but it also proved to be a dead end. In 1954, Sakharov worked on a third concept, a two-stage thermonuclear bomb. The third idea used the radiation wave of a fission bomb, not simply heat and compression, to ignite the fusion reaction, and paralleled the discovery made by Ulam and Teller. Unlike the RDS-6S boosted bomb, which placed the fusion fuel inside the primary A-bomb trigger, the thermonuclear super placed the fusion fuel in a secondary structure a small distance from the A-bomb trigger, where it was compressed and ignited by the A-bomb's x-ray radiation.

Von Neumann's response was that "sometimes someone confesses a sin in order to take credit for it." Von Neumann continued unperturbed in his work and became, along with Edward Teller, one of those who sustained the hydrogen bomb project. He collaborated with Klaus Fuchs on further development of the bomb, and in 1946 the two filed a secret patent on "Improvement in Methods and Means for Utilizing Nuclear Energy", which outlined a scheme for using a fission bomb to compress fusion fuel to initiate nuclear fusion. The Fuchs–von Neumann patent used radiation implosion, but not in the same way as is used in what became the final hydrogen bomb design, the Teller–Ulam design.

Not all the atomic bomb maidens left for the US. Miyoko Matsubara states that she was one of 16 young "Hiroshima maidens" who received surgeries in Tokyo and then Osaka in 1953. After the 10 successful operations, together with 2 other Hiroshima maidens, they were then well enough and thus started work as live-in caretakers to disadvantaged children. When time came in 1955 to travel to Mt. Sinai Hospital in the US, unlike her two colleagues, she did not feel comfortable traveling to the country that bombed her and was "left behind alone". None of the nearly equally disfigured young women at Nagasaki following the Fat Man fission bomb explosion on August 9, 1945, were in the group.

There was reasonable confidence in knowing the size of the Soviet fission bomb inventory, but much less confidence about estimates of the biological and chemical warfare capabilities. The report observed, however, that a good deal of information could be derived from knowledge of Soviet science in disciplines that supported biological and chemical warfare. Concern was expressed about knowledge of their progress of their thermonuclear weapon development program Joe-4, their first test, took place in August of the same year and their rate of uranium 235 production. While the CIA was confident on its knowledge of Soviet electronic warfare capabilities, there were gaps in the knowledge about the electronic order of battle in the Soviet air defense network.

When fired, it creates a strong electromagnetic pulse, which is inductively coupled into one or more secondary coils connected to the bridge wires or slapper foils. A low energy density capacitor equivalent to a compression generator would be roughly the size of a soda can. The energy in such a capacitor would be ·C·V, which for the above-mentioned capacitor is 12.5 J. (By comparison, a defibrillator delivers ~200 J from 2 kV and perhaps 20 µF. The flash-strobe in a disposable camera is typically 3 J from a 300 V capacitor of 100 µF.) In a fission bomb, the same or similar circuit is used for powering the neutron trigger, the initial source of fission neutrons.

A yield of 19 kilotons is given in some references for an unspecified version, possibly a not-deployed high yield test only unit. The W30 is stated by nuclear researcher Chuck Hansen to have been one of two weapons using a common fission bomb core design, the Boa primary; the other weapon using the Boa is claimed to have been the 200 kiloton W52 thermonuclear warhead. The W30 and W31 warheads used simple 3-digit lockout controls on their arming components, and could not be made safe by environmental sensing devices due to their use profile. Other warheads could use sensors to detect whether they had actually been through re-entry or sudden deceleration, prior to arming the weapon.

The standard high-fission thermonuclear weapon is automatically a weapon of radiological warfare, as dirty as a cobalt bomb. Initially, gamma radiation from the fission products of an equivalent size fission-fusion-fission bomb are much more intense than Co-60: 15,000 times more intense at 1 hour; 35 times more intense at 1 week; 5 times more intense at 1 month; and about equal at 6 months. Thereafter fission drops off rapidly so that Co-60 fallout is 8 times more intense than fission at 1 year and 150 times more intense at 5 years. The very long-lived isotopes produced by fission would overtake the 60Co again after about 75 years.

The space between the blast-chamber and the rock cavity walls was to be filled with concrete; then the bolts were to be put under enormous tension to pre-stress the rock, concrete, and blast-chamber. The blast-chamber was then to be partially filled with molten fluoride salts to a depth of 30 m (100 ft), a "waterfall" would be initiated by pumping the salt to the top of the chamber and letting it fall to the bottom. While surrounded by this falling coolant, a 1-kiloton fission bomb would be detonated; this would be repeated every 45 minutes. The fluid would also absorb neutrons to avoid damage to the walls of the cavity.

While overheating of a reactor can lead to, and has led to, meltdown and steam explosions, the much lower uranium enrichment makes it impossible for a nuclear reactor to explode with the same destructive power as a nuclear weapon. It is also difficult to extract useful power from a nuclear bomb, although at least one rocket propulsion system, Project Orion, was intended to work by exploding fission bombs behind a massively padded and shielded spacecraft. The strategic importance of nuclear weapons is a major reason why the technology of nuclear fission is politically sensitive. Viable fission bomb designs are, arguably, within the capabilities of many, being relatively simple from an engineering viewpoint.

In January 1986, Soviet leader Mikhail Gorbachev publicly proposed a three- stage program for abolishing the world's nuclear weapons by the end of the 20th century. Two years before his death in 1989, Andrei Sakharov's comments at a scientists’ forum helped begin the process for the elimination of thousands of nuclear ballistic missiles from the US and Soviet arsenals. Sakharov (1921–89) was recruited into the Soviet Union's nuclear weapons program in 1948, a year after he completed his doctorate. In 1949 the US detected the first Soviet test of a fission bomb, and the two countries embarked on a desperate race to design a thermonuclear hydrogen bomb that was a thousand times more powerful.

In a fission bomb, at sea level, the total radiation pulse energy which is composed of both gamma rays and neutrons is approximately 5% of the entire energy released; in neutron bombs it would be closer to 40%, with the percentage increase coming from the higher production of neutrons. Furthermore, the neutrons emitted by a neutron bomb have a much higher average energy level (close to 14 MeV) than those released during a fission reaction (1–2 MeV). Technically speaking, every low yield nuclear weapon is a radiation weapon, including non-enhanced variants. All nuclear weapons up to about 10 kilotons in yield have prompt neutron radiation as their furthest-reaching lethal component.

Theodore Taylor was involved in many important projects and made numerous contributions to nuclear development for the United States. During his time at Los Alamos, He was responsible for designing the smallest fission bomb of the era, named Davy Crockett, which weighed only 50 pounds, measured approximately 12 inches across, and could produce between 10 and 20 tons of TNT equivalent. This device was formerly known as the M28 Weapons System. The Davy Crockett itself was the M388 Atomic Round fired from the weapons system, featuring a recoilless rifle either erected and fixed on as freestanding tripod or mounted on the frame of a light utility vehicle, such as the Jeep, the former functioned similarly to other modern rocket propelled rounds (see RPG-7).

Critical Nuclear Weapon Design Information (CNWDI, often pronounced SIN-widdy or SIN-wuh-dee) is a U.S. Department of Defense (DoD) category of Top Secret Restricted Data or Secret Restricted Data that reveals the theory of operation or design of the components of a thermonuclear or fission bomb, warhead, demolition munition, or test device. Specifically excluded is information concerning arming, fuzing, and firing systems; limited life components; and total contained quantities of fissionable, fusionable, and high explosive materials by type. Among these excluded items are the components that DoD personnel set, maintain, operate, test or replace. The sensitivity of DoD CNWDI is such that access is granted to the absolute minimum number of employees who require it for the accomplishment of assigned responsibilities on a classified contract.

As the first successful (uncontrolled) release of nuclear fusion energy, which made up a small fraction of the 225 kt total yield, it raised expectations to a near certainty that the concept would work. On 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 10.4 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.

All current thermonuclear weapons use a fission bomb as a first stage to create the high temperatures and pressures necessary to start a fusion reaction between deuterium and tritium in a second stage. For many years, nuclear weapon designers have researched whether it is possible to create high enough temperatures and pressures inside a confined space to ignite a fusion reaction, without using fission. Pure fusion weapons offer the possibility of generating arbitrarily small nuclear yields because no critical mass of fissile fuel need be assembled for detonation, as with a conventional fission primary needed to spark a fusion explosion. There is also the advantage of reduced collateral damage stemming from fallout because these weapons would not create the highly radioactive byproducts associated with fission-type weapons.

The United Kingdom Atomic Energy Authority Atomic Weapons Establishment at Aldermaston in Berkshire was directed by William Penney, with William Cook as his deputy. The scientists at Aldermaston did not know how to build a hydrogen bomb, but produced three designs: Orange Herald, a large boosted fission weapon in which the fission yield was increased ("boosted") through the addition of lithium-6 deuteride; Green Bamboo, an interim thermonuclear design in which fusion occurred in layers of lithium-6 deuteride that alternated with layers of uranium-235; and Green Granite, a true thermonuclear design in which the thermonuclear fuel was separate and the majority of the yield came from thermonuclear burning. The British bomb designers used the terms "Tom" and "Dick" for the bomb's primary and secondary stages respectively. The Tom would be a fission bomb.

The first group consisted of the thermonuclear device (Shakti I), the fission device (Shakti II), and a sub- kiloton device (Shakti III). The second group consisted of the remaining two sub-kiloton devices Shakti IV and V. It was decided that the first group would be tested on 11 May and the second group on 13 May. The thermonuclear device was placed in a shaft code named 'White House', which was over deep, the fission bomb was placed in a deep shaft code named 'Taj Mahal', and the first sub-kiloton device in 'Kumbhkaran'. The first three devices were placed in their respective shafts on 10 May, and the first device to be placed was the sub-kiloton device in the 'Kumbhkaran' shaft, which was sealed by the army engineers by 8:30 pm.

A dirty bomb or radiological dispersal device is a speculative radiological weapon that combines radioactive material with conventional explosives. The purpose of the weapon is to contaminate the area around the dispersal agent/conventional explosion with radioactive material, serving primarily as an area denial device against civilians. It is, however, not to be confused with a nuclear explosion, such as a fission bomb, which by releasing nuclear energy produces blast effects far in excess of what is achievable by the use of conventional explosives. Although a radiological dispersal device is designed to disperse radioactive material over a large area, a bomb that uses conventional explosives and produces a blast wave would be far more lethal to people than the hazard posed by radioactive material that may be mixed with the explosive.

Fermi served on the AEC General Advisory Committee, an influential scientific committee chaired by Robert Oppenheimer. He also liked to spend a few weeks of each year at the Los Alamos National Laboratory, where he collaborated with Nicholas Metropolis, and with John von Neumann on Rayleigh–Taylor instability, the science of what occurs at the border between two fluids of different densities. Laura and Enrico Fermi at the Institute for Nuclear Studies, Los Alamos, 1954 After the detonation of the first Soviet fission bomb in August 1949, Fermi, along with Isidor Rabi, wrote a strongly worded report for the committee, opposing the development of a hydrogen bomb on moral and technical grounds. Nonetheless, Fermi continued to participate in work on the hydrogen bomb at Los Alamos as a consultant.

After the United States tested the "Ivy Mike" thermonuclear device in November 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 and free deuterium. 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 early 1954.

The yield of the test has been estimated at by different sources over time. Today all Russian sources use 50 megatons as the official figure. See the section "Was it 50 Megatons or 57?" at This is equivalent to about 1,570 times the combined energy of the bombs that destroyed Hiroshima and Nagasaki, 10 times the combined energy of all the conventional explosives used in World War II, one quarter of the estimated yield of the 1883 eruption of Krakatoa and 10% of the combined yield of all nuclear tests to date. A three-stage hydrogen bomb uses a fission bomb primary to compress a thermonuclear secondary, as in most hydrogen bombs, and then uses energy from the resulting explosion to compress a much larger additional thermonuclear stage.

Sikka, receiving the instructions, set up a laboratory with facilities for static pressure generation employing diamond anvil cells and shock waves generation with gas guns, the first such laboratory in India. The researches here assisted in the development of computer codes for design, simulation and yield estimates of nuclear explosives and, aided by these work, he is known to have developed a freshly designed device using a boosted fission bomb primary, to be used on a ballistic missile. His researches have been documented by way of over 150 articles, published in national and international peer reviewed journals. Sikka served as a member of the Executive Committee of the International Association for Advancement of Research and Technology under High Pressure from 1997 to 2000 and as a consultant to the Commission on High Pressure of International Union of Crystallography from 2002 to 2006.

Egon Bretscher worked in Teller's Super group, as did Anthony French, who later recalled that "never at any time did I have anything to do with the fission bomb once I went to Los Alamos." Four members of the British Mission became group leaders: Bretscher (Super Experimentation), Frisch (Critical Assemblies and Nuclear Specifications), Peierls (Implosion Hydrodynamics) and George Placzek (Composite Weapon).Members of the British mission to Los Alamos were: Aage Bohr (Denmark), Niels Bohr (Denmark), Egon Bretscher, James Chadwick, Lord Cherwell, Boris Davidson. Anthony French, Otto Frisch, Klaus Fuchs, James Hughes, Derrick Littler, Carson Mark (Canada), William Marley, Donald Marshall, G. A. McMillan, Philip Moon, Mrs Philip Moon, Mark Oliphant (Australia), Rudolf Peierls, Lord Portal, William Penney, George Placzek, Michael Poole, Joseph Rotblat (Poland), Herold Sheard, Tony Skyrme, Geoffrey Taylor, Ernest Titterton, Mrs Ernest Titterton, James L. Tuck and W. L. Webster.

Research has been done into the possibility of pure fusion bombs: nuclear weapons that consist of fusion reactions without requiring a fission bomb to initiate them. Such a device might provide a simpler path to thermonuclear weapons than one that required development of fission weapons first, and pure fusion weapons would create significantly less nuclear fallout than other thermonuclear weapons, because they would not disperse fission products. In 1998, the United States Department of Energy divulged that the United States had, "...made a substantial investment" in the past to develop pure fusion weapons, but that, "The U.S. does not have and is not developing a pure fusion weapon", and that, "No credible design for a pure fusion weapon resulted from the DOE investment".U.S. Department of Energy, Restricted Data Declassification Decisions, 1946 to the Present (RDD-8) (January 1, 2002), accessed November 20, 2011.

Since tritium undergoes radioactive decay, and is also difficult to confine physically, the much larger secondary charge of heavy hydrogen isotopes needed in a true hydrogen bomb uses solid lithium deuteride as its source of deuterium and tritium, producing the tritium in situ during secondary ignition. During the detonation of the primary fission bomb stage in a thermonuclear weapon (Teller-Ullam staging), the sparkplug, a cylinder of 235U/239Pu at the center of the fusion stage(s), begins to fission in a chain reaction, from excess neutrons channeled from the primary. The neutrons released from the fission of the sparkplug split lithium-6 into tritium and helium-4, while lithium-7 is split into helium-4, tritium, and one neutron. As these reactions occur, the fusion stage is compressed by photons from the primary and fission of the 238U or 238U/235U jacket surrounding the fusion stage.

On July 6, the microphones picked up the following conversation between Werner Heisenberg and Kurt Diebner, both of whom had worked on the German nuclear project and had been seized as part of the Allied Alsos Mission, Diebner in BerlinAtomic Heritage Foundation:The Alsos Mission and Heisenberg in Urfeld: All of the scientists expressed shock when informed of the atomic bombing of Hiroshima on August 6, 1945. Some first doubted that the report was genuine. They were told initially of an official announcement that an "atomic bomb" had been dropped on Hiroshima, with no mention of uranium or nuclear fission. Harteck said that he would have understood the words "uranium" or "nuclear (fission) bomb", but he had worked with atomic hydrogen and atomic oxygen and thought that American scientists might have succeeded in stabilising a high concentration of (separate) atoms; such a bomb would have had a tenfold increase over a conventional bomb.

The mushroom cloud of the atomic bomb dropped on Nagasaki, Japan on August 9, 1945, rose over above the bomb's hypocenter. An estimated 39,000 people were killed by the atomic bomb,The Atomic Bombings of Hiroshima and Nagasaki. atomicarchive.com of whom 23,145–28,113 were Japanese factory workers, 2,000 were Korean slave laborers, and 150 were Japanese combatants. One class of nuclear weapon, a fission bomb (not to be confused with the fusion bomb), otherwise known as an atomic bomb or atom bomb, is a fission reactor designed to liberate as much energy as possible as rapidly as possible, before the released energy causes the reactor to explode (and the chain reaction to stop). Development of nuclear weapons was the motivation behind early research into nuclear fission which the Manhattan Project during World War II (September 1, 1939 – September 2, 1945) carried out most of the early scientific work on fission chain reactions, culminating in the three events involving fission bombs that occurred during the war.

In November 2012, during the planning stages of Operation Hammer of God, British Labour peer Lord Gilbert suggested that multiple enhanced radiation reduced blast (ERRB) warheads could be detonated in the mountain region of the Afghanistan-Pakistan border to prevent infiltration. He proposed to warn the inhabitants to evacuate, then irradiate the area, making it unusable and impassable. Used in this manner, the neutron bomb(s), regardless of burst height, would release neutron activated casing materials used in the bomb, and depending on burst height, create radioactive soil activation products. In much the same fashion as the area denial effect resulting from fission product (the substances that make up most fallout) contamination in an area following a conventional surface burst nuclear explosion, as considered in the Korean War by Douglas MacArthur, it would thus be a form of radiological warfare—with the difference that neutron bombs produce half, or less, of the quantity of fission products relative to the same-yield pure fission bomb.

With considerable overlap between the two devices, the prompt radiation effects of a pure fusion weapon would similarly be much higher than that of a pure- fission device: approximately twice the initial radiation output of current standard fission-fusion-based weapons. In common with all neutron bombs that must presently derive a small percentage of trigger energy from fission, in any given yield a 100% pure fusion bomb would likewise generate a more diminutive atmospheric blast wave than a pure-fission bomb. The latter fission device has a higher kinetic energy-ratio per unit of reaction energy released, which is most notable in the comparison with the D-T fusion reaction. A larger percentage of the energy from a D-T fusion reaction, is inherently put into uncharged neutron generation as opposed to charged particles, such as the alpha particle of the D-T reaction, the primary species, that is most responsible for the coulomb explosion/fireball.

Fission products are more deadly than neutron-activated cobalt in the first few weeks following detonation. After one to six months, the fission products from even a large-yield thermonuclear weapon decay to levels tolerable by humans. The large-yield two-stage (a fission trigger/primary with a fusion–fission secondary) thermonuclear weapon is thus automatically a weapon of radiological warfare, but its fallout decays much more rapidly than that of a cobalt bomb. A cobalt bomb's fallout on the other hand would render affected areas effectively stuck in this interim state for decades: habitable, but not safe for constant habitation. Initially, gamma radiation from the fission products of an equivalent size fission-fusion- fission bomb are much more intense than Co-60: 15,000 times more intense at 1 hour; 35 times more intense at 1 week; 5 times more intense at 1 month; and about equal at 6 months. Thereafter fission product fallout radiation levels drop off rapidly, so that Co-60 fallout is 8 times more intense than fission at 1 year and 150 times more intense at 5 years.