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History of nuclear weapons

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Vitruvius
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« Reply #15 on: September 05, 2007, 11:14:27 pm »

Soviet atomic bomb project

The Soviet Union was not invited to share in the new weapons developed by the United States and the other Allies. During the war, information had been pouring in from a number of volunteer spies involved with the Manhattan Project (known in Soviet cables under the code-name of Enormoz), and the Soviet nuclear physicist Igor Kurchatov was carefully watching the Allied weapons development. It came as no surprise to Stalin when Truman had informed him at the Potsdam conference that he had a "powerful new weapon." Truman was shocked at Stalin's lack of interest.

The Soviet spies in the U.S. project were all volunteers and none were Russians. One of the most valuable, Klaus Fuchs, was a German émigré theoretical physicist who had been a part in the early British nuclear efforts and had been part of the UK mission to Los Alamos during the war. Fuchs had been intimately involved in the development of the implosion weapon, and passed on detailed cross-sections of the "Trinity" device to his Soviet contacts. Other Los Alamos spies—none of whom knew each other—included Theodore Hall and David Greenglass. The information was kept but not acted upon, as Russia was still too busy fighting the war in Europe to devote resources to this new project.

In the years immediately after World War II, the issue of who should control atomic weapons became a major international point of contention. Many of the Los Alamos scientists who had built the bomb began to call for "international control of atomic energy", often calling for either control by transnational organizations or the purposeful distribution of weapons information to all superpowers, but due to a deep distrust of the intentions of the Soviet Union, both in postwar Europe and in general, the policy-makers of the United States worked to attempt to secure an American nuclear monopoly. A half-hearted plan for international control was proposed at the newly formed United Nations by Bernard Baruch ("The Baruch Plan"), but it was clear both to American commentators—and to the Soviets—that it was an attempt primarily to stymie Russian nuclear efforts. The Soviets vetoed the plan, effectively ending any immediate postwar negotiations on atomic energy, and made overtures towards banning the use of atomic weapons in general.

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« Reply #16 on: September 05, 2007, 11:15:18 pm »



The iron hand of NKVD chief Lavrenty Beria was put in charge of the Russian project.
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« Reply #17 on: September 05, 2007, 11:16:09 pm »

All the while, the Soviets had put their full industrial and manpower might into the development of their own atomic weapons. The initial problem for the Soviets was primarily one of resources—they had not scouted out uranium resources in the Soviet Union and the U.S. had made deals to seize monopolies over the largest known reserves in the Belgian Congo. The USSR used penal labour to mine the old deposits in Czechoslovakia—now an area under their control—and searched for other domestic deposits (which were eventually found).

Two days after the bombing of Nagasaki, the U.S. government released an official technical history of the Manhattan Project, authored by Princeton physicist Henry DeWolf Smyth, known colloquially as the Smyth Report. The sanitized summary of the wartime effort focused primarily on the production facilities and scale of investment, written in part to justify the wartime expenditure to the American public. The Soviet program, under the suspicious watch of former NKVD chief Lavrenty Beria (a participant and victor in Stalin's Great Purge of the 1930s), would use the Report as a blueprint, seeking to duplicate as much as possible the American effort. The "secret cities" used for the Soviet equivalents of Hanford and Oak Ridge literally vanished from the maps for decades to come.

At the Soviet equivalent of Los Alamos, Arzamas-16, physicist Yuli Khariton led the scientific effort to develop the weapon. Beria distrusted his scientists, however, and he distrusted the carefully collected espionage information. As such, Beria assigned multiple teams of scientists to the same task without informing each team of the other's existence. If they arrived at different conclusions, Beria would bring them together for the first time and have them debate with their newfound counterparts. Beria used the espionage information as a way to double-check the progress of his scientists, and in his effort for duplication of the American project even rejected more efficient bomb designs in favor of ones which more closely mimicked the tried-and-true "Fat Man" bomb used by the U.S. against Nagasaki.

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« Reply #18 on: September 05, 2007, 11:17:06 pm »



The first Soviet bomb, "Joe-1," was tested on August 29, 1949.
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« Reply #19 on: September 05, 2007, 11:17:39 pm »

Working under a stubborn and scientifically ignorant administrator, the Soviet scientists struggled on. On August 29, 1949, the effort brought its results, when the USSR tested its first fission bomb, dubbed "Joe-1" in the U.S., years ahead of American predictions. The news of the first Soviet bomb was announced to the world first by the United States, which had detected the nuclear fallout it generated from its test site in Kazakhstan.

The loss of the American monopoly on nuclear weapons marked the first tit-for-tat of the nuclear arms race. The response in the U.S. was one of apprehension, fear, and scapegoating, which would lead eventually into the Red-baiting tactics of McCarthyism. Before this, though, President Truman would announce his decision to begin a crash program to develop a far more powerful weapon than those which were used against Japan: the hydrogen bomb.

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« Reply #20 on: September 05, 2007, 11:18:39 pm »

The first thermonuclear weapons

The notion of using a fission weapon to ignite a process of nuclear fusion can be dated back to 1942 . At the first major theoretical conference on the development of an atomic bomb hosted by J. Robert Oppenheimer at the University of California, Berkeley, participant Edward Teller directed the majority of the discussion towards Enrico Fermi's idea of a "Super" bomb which would utilize the same reactions which powered the Sun itself. It was thought at the time that a fission weapon would be quite simple to develop and that perhaps work on a hydrogen bomb would be possible to complete before the end of the Second World War. However, in reality the problem of a "regular" atomic bomb was large enough to preoccupy the scientists for the next few years, much less the more speculative "Super." Only Teller continued working on the project—against the will of project leaders Oppenheimer and Hans Bethe.

After the atomic bombings of Japan, many scientists at Los Alamos rebelled against the notion of creating a weapon thousands of times more powerful than the first atomic bombs. For the scientists the question was in part technical—the weapon design was still quite uncertain and unworkable—and in part moral: such a weapon, they argued, could only be used against large civilian populations, and could thus only be used as a weapon of genocide. Many scientists, such as Bethe, urged that the United States should not develop such weapons and set an example towards the Soviet Union. Promoters of the weapon, including Teller, Ernest Lawrence, and Luis Alvarez, argued that such a development was inevitable, and to deny such protection to the people of the United States—especially when the Soviet Union was likely to create such a weapon themselves—was itself an immoral and unwise act.

Oppenheimer, who was now head of the General Advisory Committee of the successor to the Manhattan Project, the Atomic Energy Commission, presided over a recommendation against the development of the weapon. The reasons were in part because the success of the technology seemed limited at the time (and not worth the investment of resources to confirm whether this was so), and because Oppenheimer believed that the atomic forces of the United States would be more effective if they consisted of many large fission weapons (of which multiple bombs could be dropped on the same targets) rather than the large and unwieldy predictions of massive super bombs, for which there were a relatively limited amounts of targets of the size to warrant such a development. Furthermore, were such weapons developed by both the U.S. and the USSR, they would be more effectively used against the U.S. than by it, as the U.S. had far more regions of dense industrial and civilian activity which would serve as ideal targets for the large weapons than the Soviet Union did.

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« Reply #21 on: September 05, 2007, 11:19:42 pm »



Hungarian physicist Edward Teller toiled for years trying to discover a way to make a fusion bomb.
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« Reply #22 on: September 05, 2007, 11:20:32 pm »

In the end, President Truman made the final decision, looking for a proper response to the first Soviet atomic bomb test in 1949 . On January 31, 1950, Truman announced a crash program to develop the hydrogen (fusion) bomb. At this point, however, the exact mechanism was still not known: the "classical" hydrogen bomb, whereby the heat of the fission bomb would be used to ignite the fusion material, seemed highly unworkable. However, an insight by Los Alamos mathematician Stanislaw Ulam showed that the fission bomb and the fusion fuel could be in separate parts of the bomb, and that radiation of the fission bomb could first work in a way to compress the fusion material before igniting it. Teller pushed the notion further, and used the results of the boosted-fission "George" test (a boosted-fission device using a small amount of fusion fuel to boost the yield of a fission bomb) to confirm the fusion of heavy hydrogen elements before preparing for their first true multi-stage, Teller-Ulam hydrogen bomb test. Many scientists initially against the weapon, such as Oppenheimer and Bethe, changed their previous opinions, seeing the development as being unstoppable.

The first fusion bomb was tested by the United States in Operation Ivy on November 1, 1952, on Elugelab Island in the Enewetak (or Eniwetok) Atoll of the Marshall Islands, code-named "Mike". "Mike" used liquid deuterium as its fusion fuel and a large fission weapon as its trigger. The device was a prototype design and not a deliverable weapon: standing over 20 ft (6 m) high and weighing at least 140,000 lb (64 t) (its refrigeration equipment added an additional 24,000 lb as well), it could not have been dropped from even the largest planes. Its explosion yielded 10.4 megatons of energy—over 450 times the power of the bomb dropped onto Nagasaki— and obliterated Elugelab, leaving an underwater crater 6240 ft (1.9 km) wide and 164 ft (50 m) deep where the island had once been. Truman had initially tried to create a media blackout about the test—hoping it would not become an issue in the upcoming presidential election—but on January 7, 1953, Truman announced the development of the hydrogen bomb to the world as hints and speculations of it were already beginning to emerge in the press.

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« Reply #23 on: September 05, 2007, 11:21:45 pm »



The "Mike" shot in 1952 inaugurated the age of fusion weapons.
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« Reply #24 on: September 05, 2007, 11:22:37 pm »

Not to be outdone, the Soviet Union exploded its first thermonuclear device, designed by the physicist Andrei Sakharov, on August 12, 1953, labeled "Joe-4" by the West. This created concern within the U.S. government and military, because, unlike "Mike," the Soviet device was a deliverable weapon, which the U.S. did not yet have. This first device though was arguably not a "true" hydrogen bomb, and could only reach explosive yields in the hundreds of kilotons (never reaching the megaton range of a "staged" weapon). Still, it was a powerful propaganda tool for the Soviet Union, and the technical differences were fairly oblique to the American public and politicians. Following the "Mike" blast by less than a year, "Joe-4" seemed to validate claims that the bombs were inevitable and vindicate those who had supported the development of the fusion program. Coming during the height of McCarthyism, the effect was most pronounced by the security hearings in early 1954 which revoked former Los Alamos director Robert Oppenheimer of his security clearance, on the grounds that he was unreliable, had not supported the American hydrogen bomb program, and had made long-standing, left-wing ties in the 1930s. Edward Teller participated in the hearing as the only major scientist to testify against Oppenheimer, a role which resulted in his virtual expulsion from the physics community.

On February 28, 1954, the U.S. detonated its first deliverable thermonuclear weapon (which used isotopes of lithium as its fusion fuel), known as the "Shrimp" device of the "Castle Bravo" test, at Bikini Atoll, Marshall Islands. The device yielded 15 megatons of energy, over twice its expected yield, and became the worst radiological disaster in U.S. history. The combination of the unexpectedly large blast and poor weather conditions caused a cloud of radioactive nuclear fallout to contaminate over 7,000 square miles, including Marshall Island natives and the crew of a Japanese fishing boat, as a snow-like mist. The contaminated islands were evacuated (and are still uninhabitable), but the natives received enough of a radioactive dose that they suffered far elevated levels of cancer and birth defects in the years to come. The crew of the Japanese fishing boat, Fifth Lucky Dragon, returned to port suffering from radiation sickness and skin burns. Their cargo, many tons of contaminated fish, managed to enter into the market before the cause of their illness was determined. When a crew member died from the sickness and the full results of the contamination were made public by the U.S., Japanese concerns were reignited about the hazards of radiation and resulted in a boycott on eating fish (a main staple of the island country) for some weeks.
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« Reply #25 on: September 05, 2007, 11:23:36 pm »



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.
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« Reply #26 on: September 05, 2007, 11:24:31 pm »

The hydrogen bomb age had a profound effect on the thoughts of nuclear war in the popular and military mind. With only fission bombs, nuclear war could be considered something which could easily be "limited." Dropped by planes and only able to destroy the most built up areas of major cities, it was possible to consider fission bombs simply a technological extension of previous wartime bombing (such as the extensive firebombing which took place against Japan and Germany during World War II), and claims that such weapons could lead to worldwide death or harm were easily brushed aside as grave exaggeration. Even the decades before the development of fission weapons there had been speculation about the possibility for human beings to end all life on the planet by either accident or purposeful maliciousness, but technology had never allowed for such a capacity. The far greater power of hydrogen bombs made this seem ever closer.

The "Castle Bravo" incident itself raised a number of questions about the survivability of a nuclear war. Government scientists in both the U.S. and the USSR had insisted that fusion weapons, unlike fission weapons, were "cleaner" as fusion reactions did not result in the dangerously radioactive by-products as did fission reactions. While technically true, this hid a more gruesome point: the last stage of a multi-staged hydrogen bomb often used the neutrons produced by the fusion reactions to induce fissioning in a jacket of natural uranium, and provided around half of the yield of the device itself. This fission stage made fusion weapons considerably more "dirty" than they were made out to be, a fact made evident by the towering cloud of deadly fallout which followed the "Bravo" test. When the Soviet Union tested its first megaton device in 1955 , the possibility of a limited nuclear war seemed even more remote in the public and political mind: even if a city or country was not the direct target of a nuclear attack, the clouds of fallout and harmful fission products would disperse along with normal weather patterns and embed themselves in the soil and water of non-targeted areas of the planet as well. Speculation began to look towards what would happen as the fallout and dust created by a full-scale nuclear exchange would affect the world as a whole, rather than just the cities and countries which had been directly involved. In this way, the fate of the world was now tied to the fate of the bomb-wielding superpowers.

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« Reply #27 on: September 05, 2007, 11:25:31 pm »



Fallout from a large nuclear exchange would potentially blanket a country—perhaps even the whole world—with radioactive fission products.
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« Reply #28 on: September 05, 2007, 11:26:34 pm »

Deterrence and brinkmanship

Throughout the 1950s and the early 1960s a number of trends were enacted between the U.S. and the USSR as they both endeavored in a tit-for-tat approach to disallow the other power from acquiring nuclear supremacy. This took form in a number of ways, both technologically and politically, and had massive political and cultural effects during the Cold War.

The first atomic bombs dropped on Hiroshima and Nagasaki were large, custom-made devices, requiring highly trained personnel for their arming and deployment. They could be dropped only from the largest bomber planes—at the time the B-29 Superfortress—and each plane could only hold a single bomb in its hold. The first hydrogen bombs were similarly massive and complicated. This ratio of one plane to one bomb was still fairly impressive in comparison with conventional, non-nuclear weapons, but against other nuclear-armed countries it was considered to be a grave danger. In the immediate postwar years, the U.S. expended much effort on making the bombs "G.I.-proof"—capable of being used and deployed by members of the U.S. Army, rather than Nobel Prize–winning scientists, and in the 1950s a program of nuclear testing was undertaken in order to improve the nuclear arsenal.

Starting in 1951 , the Nevada Test Site (in the Nevada desert) became the primary location for all U.S. nuclear testing (in the USSR, Semipalatinsk Test Site in Kazakhstan served a similar role). Tests were divided into two primary categories: "weapons related" (verifying that a new weapon worked or looking at exactly how it worked) and "weapons effects" (looking at how weapons behaved under various conditions or how structures behaved when subjected to weapons). In the beginning, almost all nuclear tests were either "atmospheric" (conducted above ground, in the atmosphere) or "underwater" (such as some of the tests done in the Marshall Islands). Testing was used as a sign of both national and technological strength, but also raised questions about the safety of the tests, which released nuclear fallout into the atmosphere (most dramatically with the Castle Bravo test in 1954 , but in more limited amounts with almost all atmospheric nuclear testing).

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« Reply #29 on: September 05, 2007, 11:27:44 pm »



The emergence of nuclear-tipped rockets reflected a change in both nuclear technology and strategy.
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