Nuclear weapons atomic bomb

One of the most significant sources of change in isotope ratios is caused by the small mass differences between isotopes and their effects on the physical properties of elements and compounds. For example, ordinary water (mostly Ej O) has a lower density, lower boiling point, and higher vapor pressure than does heavy water (mostly H2 0). Other major changes can occur through exchange processes. Such physical and kinetic differences lead to natural local fractionation of isotopes. Artificial fractionation (enrichment or depletion) of uranium isotopes is the basis for construction of atomic bombs, nuclear power reactors, and depleted uranium weapons. 

I- n -> La -I- Br -i- 3n The energy released is approximately 3 x 10 J per nucleus. For 1 kg of this is equivalent to 20 000 megawatt-hours - the amount of energy produced by the combustion of 3 X 10 tonnes of coal. Nuclear fission is the process used in nuclear reactors and atom bombs (sccnuclear weapons). 

A simple nuclear weapon derives its energy from nuclear fission. A mass of fissionable material is rapidly assembled into a critical mass, in which a chain reaction develops and releases tremendous amounts of energy. This is known as an atomic bomb. Nuclear fusion can be used to make a more powerful weapon. In such a weapon, the X-ray thermal radiation from a nuclear fission explosion is used to heat and compress a small amount of tritium, deuterium, or hthium, causing nuclear fusion, releasing even more energy. Such a weapon is called a hydrogen bomb and can be hundreds of times more powerful than an atomic bomb. 

Atomic bomb. A weapon of mass destruction. The term is sometimes taken to mean a nuclear weapon utilizing fission energy only, but it is applicable to hydrogen fusion weapons as well. It is appropriate to call both atomic weapons because the energy released by atomic nuclei is involved in each case. The energy of an atomic explosion is released in a number of ways ... 

There are two different kinds of nuclear weapons. Weapons based on the fission process ( atomic bombs ) and weapons based on the nuclear fusion reaction ( hydrogen bombs ). The fusion weapons get most of their energy from a fusion process of fight nuclides (like deuterium) to helium. Fusion weapons contain a small fission bomb that serves to heat the fusion matter to a temperature of about 10 K required for the start of the fusion process. 

The process of nuclear fission was discovered more than half a century ago in 1938 by Lise Meitner (1878-1968) and Otto Hahn (1879-1968) in Germany. With the outbreak of World War II a year later, interest focused on the enormous amount of energy released in the process. At Los Alamos, in the mountains of New Mexico, a group of scientists led by J. Robert Oppenheimer (1904-1967) worked feverishly to produce the fission, or atomic, bomb. Many of the members of this group were exiles from Nazi Germany. They were spurred on by the fear that Hitler would obtain the bomb first Their work led to the explosion of the first atomic bomb in the New Mexico desert at 5 30 a.m. on July 16,1945. Less than a month later (August 6,1945), the world learned of this new weapon when another bomb was exploded... 

The potential of nuclear fission was first realized in the atomic bomb. In 1945, the United States dropped two bombs of unprecedented power, one on Hiroshima and the other on Nagasaki, Japan. Both were fission weapons. 

This section summarizes the key events that led the United States to be the first country to successfully develop the atomic bomb. It also discusses the world s current nuclear weapons arsenal and details the uses of other types of radioactive materials as terrorist weapons. 

Shortly after Japan s December 7,1941 attack on Pearl Harbor, the U.S. became more driven to expedite its timetable for developing the first fission weapon because of fear that the U.S. lagged behind Nazi Germany in efforts to create the first atomic bomb. On December 2, 1942 at 3 49 p.m., Enrico Fermi and Samuel K. Allison achieved the world s first controlled, self-sustained nuclear chain reaction in an experimental reactor using natural uranium and graphite. 

The British aircraft industry appeared to be backward compared with its American and Soviet counterparts, but this was mainly because the expectation that the maximum danger of war lay in the future, about 1957, led to a gap in British development and production of a number of important weapons systems. The timing of up-to-date strategic bombers was linked to the development of the British atomic bomb, which, although first tested in October 1952, would not be ready for operational use until about 1956. Meanwhile Britain was wholly dependent on the United States for nuclear deterrence. 

The Buccaneer, with its capacity to carry nuclear weapons, was central to the Admiralty s vision of the aircraft carrier as the modem equivalent of the capital ship. In a remarkable paper, dated 2 March 1954, the Admiralty set out its views on expected trends in naval weapons down to the end of 1965. The news of the American hydrogen-bomb tests came too late to influence the paper, which, however, assumed that atomic weapons would be plentiful that the importance of air attack would increase but that long-range detection of submarines and torpedo countermeasures would reduce the underwater threat to surface ships. It was predicted that by the 1960s carrier-borne aircraft would carry nuclear weapons and would contribute to the strategic air offensive aircraft and 200-mile-range anti-ship missiles would have begun to... 

Fission weapons or bombs They derive their power from nuclear fission when heavy nuclei such as uranium (U) or plutonium (Pu) are bombarded by neutrons and split into lighter elements, more neutrons and energy. The newly generated neutrons then bombard other nuclei which then split and bombard other nuclei and so on. This process continues and leads to a nuclear chain reaction which releases large amount of energy. These are also historically called atomic bombs or atom bombs or A-bombs. 

Other specific types of nuclear weapons are commonly referred to by their names such as neutron bombs (enhanced radiation weapons), cobalt bombs and salted bombs. The atomic bomb was the first nuclear weapon to be developed, tested and used. It was developed under the direction of American physicist J. Robert Oppenheimer (1904—1967) and implemented toward the end of World War... 

With the advent of nuclear weapons, particularly thermonuclear devices (hydrogen bombs), additional 14C was added to the atmosphere. This 14C, which we shall refer to as excess 14C, was produced by neutrons which escaped from the fireball interacting with nitrogen atoms of the atmosphere in the same manner as the neutrons from cosmic rays. Since the bulk of this 14C was probably produced by a few very high energy devices exploded high in the atmosphere, most of the excess 14C was likewise deposited in the stratosphere. 

Atomic (or Nuclear) Bomb. A weapon invented during WWII and developed in the United States as a joint effort with the British and Canadian governments. It utilizes for its destructive effect the energy of an Atomic or Nuclear Explosion (qv). Since atomic explosions are of two types, fission and fusion, atomic bombs are of. corresponding types. However, it has been necessary to first initiate an atomic explosion with a nuclear fission reaction in order to bring about the conditions under which a nuclear fusion(thermonuclear) reaction can occur. 

In 1988 the speaker of the Iranian parliament, Hashemi Rafsanjani, described chemical weapons as the poor man s atomic bomb. 2 This phrase is as accurate as it is alarming. While many would argue that nuclear weapons represent the zenith of mass destruction, their construction requires advanced industrial capabilities as well as access to rare, tightly controlled materials. Chemical weapons, on the other hand, are comparatively cheap and easy to build using equipment and chemicals that are used extensively for a host of civilian purposes. With... 

Nuclear Explosions Although conventional explosives have become the weapons of choice of terrorist groups, a joint report issued in 2008 by Harvard s Kennedy School of Government and the Nuclear Threat Initiative reminds us that there is a real danger that terrorists could get and use a nuclear weapon.16 In order to understand what this would mean, we return to the atomic nucleus. A nuclear fission reaction releases far more energy than any ordinary chemical process. The Oklahoma City bomb was equivalent to the explosion of approximately 40001b of TNT.17 In contrast, the atomic bomb dropped on... 

As with other technology, nuclear technology involves a combination of science and art. However, it is unique because of the development of the atomic bomb that contributed to the ending of World War II. Many people view nuclear technology from the point of view of nuclear weapons and more recently nuclear accidents such as those at Chernobyl and Three Mile Island. This leads to the view that nuclear technology is only useful for explosive applications and that it is only with great care that it can be safely used. In reality, it is difficult to produce nuclear explosions... 

How well founded was this belief became public on August 6, 1945, when an atom bomb was dropped on Hiroshima. To be sure, the alchemists had not been looking for a weapon which could destroy civilization. They were seeking a philosopher s stone which could turn the cheaper metals such as iron and lead into the more precious gold, and an elixir of life which would retard old age. To the social-minded scientist the conquest of nuclear energy means a modern philosopher s stone which, if used wisely, could improve the health and wellbeing of tens of millions of people all over the world. 

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