Nuclear Weapon(redirected from First nuclear fission bomb)
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nuclear weapon[′nü·klē·ər ′wep·ən]
(also atomic weapon), a weapon in which the damage is inflicted by a nuclear charge. A nuclear weapon comprises a nuclear warhead; a delivery system, that is, the means of delivering the weapon to the target (missile, torpedo, aircraft, artillery fire); and a guidance system, which ensures that the warhead will reach the specified target. A distinction is made between nuclear weapons proper and thermonuclear weapons. The action of nuclear weapons is based on the use of the destructive properties of a nuclear explosion (see).
As a means of mass destruction, nuclear weapons are intended for the immediate destruction of administrative centers, industrial and military installations, troops, and naval forces and for the creation of zones of mass annihilation; they cause flooding, fires, and radioactive contamination of the environment. Nuclear weapons have a strong moral and psychological effect on people. The power of a nuclear warhead is expressed in terms of the TNT equivalent. Modern nuclear warheads have a TNT equivalent ranging from a few dozen tons to a few tens of millions of tons of TNT. In the literature, the power of nuclear weapons is often expressed in kilotons or megatons, and the words “TNT equivalent” are omitted.
Nuclear weapons can be used by all branches of the armed forces. Depending on the purpose of the weapon, the power of the charge, and the strike capabilities of the delivery system, it is customary to subdivide nuclear weapons into strategic weapons, which are directed against important strategic installations deep in enemy territory (such weapons are under the control of the highest political and military authority of the government); tactical-operational weapons, which are directed against various installations at the depth of tactical operations; and tactical weapons, which are directed against troops, materiel, and rear-line and other installations within the tactical zone.
Isolated, grouped, or massed nuclear strikes can be made with the use of nuclear weapons. Isolated and grouped strikes are delivered against one target or a group of targets by one or several nuclear warheads, respectively, while massed strikes are delivered against a large group of installations (targets) or a large group of several dispersed groups of land or naval forces by a large number of nuclear warheads.
A number of nuclear weapon effects arise upon the explosion: shock wave, thermal radiation, penetrating radiation, radioactive contamination, and electromagnetic surge. The shock wave acts on all objects encountered in its path. For example, upon an air burst of a nuclear warhead with a TNT equivalent of 100 kilotons, the shock wave kills people unprotected by shelter within a range of 1.6 km from the epicenter of the blast and totally destroys multistory stone buildings within a radius of up to 4.5 km. The thermal radiation accompanying the blast melts, chars, deforms, and ignites various materials. Living tissue is burned with varying degrees of severity. For people unprotected by shelter, the thermal radiation accompanying an air burst of a 100-kiloton nuclear warhead is lethal within a range of 1.4 km and causes third-degree burns at 3.5 km, second-degree burns at 3.8 km, and first-degree (disabling) burns at 5 km; fires occur within a range of 7 km. Penetrating radiation (the flux of gamma rays and neutrons accompanying a nuclear blast, lasting 10–15 sec) causes radiation sickness. For people unprotected by shelter, the penetrating radiation that accompanies the surface burst of a 100-kiloton nuclear warhead is fatal up to a distance of 1 km and causes third-degree burns at 1.7 km, second-degree burns at 1.9 km, and first-degree burns at 2 km. Radioactive contamination of the terrain and the objects within it occurs both as a result of radioactive fallout from the cloud of the nuclear blast and as a result of induced radiation, caused by the formation of radioactive isotopes in the surrounding atmosphere under the action of prompt neutron and gamma radiation of the nuclear blast. In this case, people and animals are affected chiefly as a result of external irradiation, whose action is similar to that of penetrating radiation. The electromagnetic surge (brief electric and magnetic fields that arise during nuclear explosions) acts upon antennas, wires, cables, and communications facilities in which voltages are induced, causing the breakdown of insulation, damage to the input elements of equipment, and the burnout of fuses. The design particulars of nuclear charges may have a strong influence on the proportion of nuclear weapon effects; for example, charges can be made with a sharply increased yield of neutron radiation (neutron bombs).
The development of nuclear weapons has been linked with the development of nuclear physics in the 20th century. In the early 1940’s, a group of scientists in the United States worked out the physical principles of a nuclear explosion. The first explosion was detonated on the proving grounds at Alamogordo, N. M., on June 16, 1945. In August 1945, two atomic bombs with a power of about 20 kilotons each were dropped on the Japanese cities of Hiroshima (August 6) and Nagasaki (August 9). The explosions of the bombs inflicted enormous civilian casualties (more than 140,000 dead in Hiroshima and about 75,000 in Nagasaki) and colossal destruction. The use of nuclear weapons was not prompted by military necessity. The ruling circles in the United States were pursuing political goals of demonstrating their own force to terrify the freedom-loving peoples and to instill fear in the USSR. The USSR soon had its own nuclear weapons, developed by a group of scientists under the leadership of Academician I. V. Kurchatov. In 1947 the Soviet government revealed that the method of making an atomic bomb was no longer a secret for the USSR, and in August 1949 the USSR tested its first atomic bomb. Having lost its monopoly on nuclear weapons, the United States intensified work, begun in 1942, on the development of thermonuclear weapons. A 3-megaton thermonuclear device was exploded in the United States on Nov. 1, 1952, and a thermonuclear bomb was tested in the United States in 1954. A similar bomb was first tested in the USSR on Aug. 12, 1953.
By the mid-1950’s, the USSR and the United States had developed and equipped the armed forces with various classes and types of delivery systems, including guided missiles, with the capability, depending on designation, of delivering nuclear warheads to various distances. In the 1960’s nuclear weapons had been introduced in all the branches of the armed forces and had a decisive influence on the organizational structure of armies and navies. They led to changes in methods of waging battles and carrying out operations and to new views regarding the conduct of war as a whole and the use of other armament. In 1960 the USSR created a special branch of the armed services: the Strategic Rocket Corps.
In addition to the USSR and the United States, the following countries have constructed and tested nuclear weapons: Great Britain (Oct. 30, 1952), France (Feb. 13, 1960), and China (Oct. 16, 1964); thermonuclear weapons were also tested by Great Britain (May 15, 1957), France (Aug. 28, 1968), and China (June 17, 1967). The USSR, the United States, France, Great Britain, and China have equipped their armed forces with nuclear weapons. More than 30 capitalist countries have the science and technology to produce nuclear weapons.
The USSR and the United States have the most varied and advanced nuclear armament. The United States has (1975) more than 30,000 nuclear warheads (including 8,000 strategic and 22,000 tactical weapons in the air force, navy, and army). It has many different types of combat-ready delivery systems for delivering the warheads to targets. By early 1976, its strategic offensive forces alone had 1,054 Titan 2, Minuteman II, and Minute-man III intercontinental ballistic missiles (ICBM’s) with nuclear warheads, more than 400 B-52 and FB-111 bombers of the strategic air command capable of carrying nuclear bombs and winged rockets with nuclear charges, and 41 nuclear submarines armed with Polaris A3 and Poseidon missiles with nuclear warheads. Great Britain has (1976) 64 Polaris nuclear ICBM’s (on four nuclear submarines), nuclear bombs, and American-made tactical missiles. France has 48 ballistic missiles (on three submarines), 27 land-based intermediate-range ballistic missiles, nuclear bombs, and tactical missiles. China (according to non-Soviet sources) has more than 100 ballistic missiles with a range of 1,600–1,800 km and about 50 ballistic missiles with a range of 2,500–4,000 km armed with nuclear warheads, as well as nuclear bombs.
Since the late 1960’s, the development of nuclear weapons in the United States and other capitalist countries has been directed primarily at increasing the number of nuclear warheads delivered to a target by a single missile, increasing the specific power of the warheads, using guidance systems that ensure high accuracy of strikes on intended targets, and improving ways of overcoming antimissile defenses. The warheads of strategic missiles in nuclear equipment can be fitted with automatic propulsion units and self-guidance systems for automatic course correction and maneuvering until the moment of impact.
Nuclear weapons pose an enormous threat to all mankind. For example, according to calculations by American specialists, the explosion of a 20-megaton thermonuclear device could raze all dwellings within a radius of up to 24 km from the explosion’s epicenter and destroy all life at a distance of up to 140 km.
Taking into account the accumulated stockpiles of nuclear weapons and their enormous destructive force, specialists believe that a nuclear world war would result in the death of hundreds of millions of people and would destroy the treasures of world civilization and culture. The danger incurred by the use of nuclear energy for military purposes has engendered a powerful worldwide movement to ban nuclear weapons.
Developing the resolutions of the Twenty-fourth and Twenty-fifth Congresses of the CPSU, the USSR proposed the nuclear disarmament of all countries having nuclear weapons. It proposed convening a conference of the five nuclear powers for this purpose, as well as the conclusion of an agreement on the immediate cessation of nuclear arms production by all governments. The USSR and other socialist countries have played a leading role in the conclusion of international agreements on banning the use of nuclear arms and in the adoption of conventions to lay the groundwork for the drafting of a universal convention banning nuclear arms.
The following have been important landmarks toward the development of international legislation prohibiting nuclear weapons: the Nuclear Test-Ban Treaty, banning nuclear tests in the atmosphere, outer space, and underwater (1963); the treaty on principles governing the activities of states in the exploration and use of outer space, including the moon and other celestial bodies (1967); the Nuclear Nonproliferation Treaty (1968); and the agreement prohibiting the emplacement of nuclear or other weapons of mass destruction on the ocean floor (1971). An important resolution was passed by the United Nations in 1972 on the non-use of force in international relations and the permanent prohibition of the use of nuclear weapons.
Important agreements have been concluded by the USSR and the United States, including an agreement on measures to reduce the risk of nuclear war (1971), according to which the countries would notify each other immediately in the event of an accidental or unauthorized use of nuclear weapons; a treaty on the limitation of antiballistic missile systems (1972); an interim agreement on certain measures with respect to the limitation of strategic offensive arms (1972); and an agreement on the prevention of nuclear war (1973). They also signed an agreement on the limitation of underground nuclear weapon tests (1974), prohibiting the USSR and the United States from underground testing of weapons above a yield of 150 kilotons by Mar. 31, 1976, and an agreement on underground nuclear explosions for peaceful purposes, which went into effect in 1976. The USSR also has an agreement with France on immediate notification in the event of an accidental or unauthorized use of nuclear weapons (1976) and an agreement with Great Britain on the prevention of accidental involvement in nuclear warfare (1977).
The USSR is strongly opposed to the production of the neutron bomb. In 1977 it proposed that the USSR and the United States conclude an agreement on the nonproduction of neutron weapons.
REFERENCESAtom i oruzhie. Moscow, 1964.
Atomnoe oruzhie. Moscow, 1957. (Translated from English.)
Vooruzhennye sily kapitalisticheskikh gosudarstv. Moscow, 1971.
Voennaia strategiia, 3rded. Moscow, 1968.
50 let Voomzhennykh Sil SSSR. Moscow, 1968.
ladernyi vzryv v kosmose, na zemle i pod zemlei. Moscow, 1974. (Collection of articles translated from English and compiled by S. L. Davydov.)