Nuclear weapon - SpeedyLook encyclopedia

The nuclear weapon is a Arme of massive destruction which uses the energy of the atom, produced either by the fission of atomic nuclei heavy (Uranium, Plutonium in the case of the bombs has), or by the fusion of atomic nuclei light (Hydrogène in the case of the H-bombs).

Its destroying effects, which are without common measurement with those of the “conventional Armes”, are not only due to the breath and the increase in the temperature, as for the traditional explosives, but also with the radiations. The energy released by the explosion is expressed by equivalence with that released by a ton of TNT.

The nuclear weapon was used operationally twice during the Second world war, by the the United States against the Japan by the bombardments of the towns of Hiroshima and Nagasaki, involving several hundreds of thousands of deaths.

Because of its power, the nuclear weapon is generally not regarded as a conventional Arme, but as a weapon of Dissuasion (political of nuclear deterrence), aiming at preventing any major attack, which would be sanctioned by the use of this weapon. Conversely, potential psychological impact of a nuclear weapon in fact a target of choice for movements or terrorist states. Since several countries obtained more or less quickly the nuclear weapon, of the international agreements aim at to reduce the nuclear arsenal and to limit the Nuclear proliferation.

History

Beginnings of the nuclear research

The physicists start to consider the use of atomic energy and the atomic bomb in the Années 1930.

The come to power of Adolf Hitler in Germany starts an immediate brain drain as of 1933, including scientists of Jewish confession who contributed then in a decisive way to the dies Frenchwoman and British; the German bomb was born never in spite of work of the institute of chemistry Kaiser-Wilheim of Berlin during the war.

The discoveries and work carried out with the Collège de France by Frederic and Irene Joliot-Curie, Hans Halban and Lew Kowarski in 1939 and 1940 are significant. Communications are made and of the patents taken at that time, including one described the principle of the atomic bomb.

The British Commission MAUD is launched during the Drôle of war and recovers the results of the French die after the rout of the Bataille of France in May 1940.

Manhattan project

Hiroshima and Nagasaki

In the morning of the August 6th of the same year, the president Harry Truman, who succeeded Franklin Roosevelt deceased the April 12th, gives the order to release an atomic bomb on a civil objective, the town of Hiroshima, with for objective making capitulate the Japan.

Even today, the reasons of this decision are far from being perfectly known. It should indeed be remembered that the Manhattan project initially aimed Germany and not Japan. The official explanation (that, at the origin, of Truman) supports that the capitulation of Japan was thus carried out by avoiding American heavy losses. For others, it is the imminence of the declaration of war of the USSR in Japan envisaged at the time of the Accords of Yalta three months after the capitulation of Germany (either at August 8th, 1945), which is the determining factor; with their new nuclear power, the USA did not need more to compose with a cumbersome ally to finish this conflict and to share profits of them (zones of influence, military bases, etc). It was the point of view of Eisenhower during the war and, at the beginning of the Cold war, the Nobel Prize of physics Patrick Blackett.

This bomb was called by the American army Little Boy (“Little boy”), because of its small size, and Pikadon (“Light and noise”) by Japanese. The Bombe has with the enriched Uranium (of revolver type) exploded by expelling an energy equivalent to approximately 15 kt of TNT. It is difficult to know with precision the number of people killed by the explosion. The American Département of energy (DOE) estimates as for him the number of instantaneously killed people at approximately: 70000 and approximately 200000 additional people in the five years which followed.

The August 9th, three days later, Truman gives the order to release one second bomb on the town of Kokura (currently Kitakyushu). This one being covered by clouds, it is Nagasaki which is then aimed: at the time of a break, the bomber confuses the factories Mitsubishi on the quays of the port with the Christian Cathédrale. The released bomb, this time, is with the Plutonium, has a power of 22 kt and is called Fat Man (“Large Catch”). Just like for Hiroshima, the number of deaths is difficult to define, the DOE estimates that there were approximately 40000 instantaneously killed people and 60000 others wounded. In January 1946, it was estimated that approximately 70000 people had died of the consequences of the explosion and perhaps the double in the five following years.

The two bombs exploded with approximately 500 meters of Altitude in order to maximize their effects which then were known little about, the Secret surrounding research on this Arme having prohibited all Expérimentation in real situation.

The August 15th, Japan accepts the unconditional surrender, the Act of the rendering of Japan is signed the September 2nd 1945, aboard battleship “ Missouri ”, which puts an end to the Second world war (after the declaration of Soviet war in Japan the August 8th 1945).

Beginning of nuclear proliferation

Nuclear deterrence

With the beginning of the Cold war and the fast accession of the Soviet Union with the nuclear force, both Superpuissance S entered what one calls “nuclear deterrence” or balance of terror.

This concept consists of the fear, in the two camps, of the use by the other of the nuclear weapon. If it were the case, attacked would retort with the same weapons and, because of the power and the effects of the nuclear weapons, each one could be completely destroyed or at least undergo very important damage, so that the advantages of being the attacker are quasi null. The stability of this configuration, where two adversaries are dissuaded thus mutually, depends above all on the capacity on attacked nucléairement to strike the other after having undergone the first atomic striking. It is what one calls the capacity of the second striking, motive fluid of the arms race which opposed both superpuissances during the Cold war.

Because of their exceptional lethal capacity in only one striking, the nuclear weapons appear today before any being of the weapons of political pressure, even if the limited use of nuclear weapon of low power in confined surroundings is sometimes considered, for example in the United States with the Minis-nuke, to destroy target-keys buried at great depth. This primacy granted to the dissuasive use of the nuclear weapon is however not universal: this one appeared gradually but quickly in the United States, but did not form part of the official doctrinal corpus of the USSR. However mutual dissuasion weighed on the relations between the two countries, as seem to testify to them the “peaceful” resolutions of the crises which punctuated the Cold war.

Reduction of the nuclear arsenals

The agreements Strategic Arms Limitation Talks (SALT), signed by the the United States and the Soviet Union in 1972 and 1979, fixed at the offensive strategic weapons of the ceilings higher than the levels than those had reached: they thus authorized their development, but limited.

The agreements Strategic Arms Reduction Treaty (START), in 1991 and 1993, imposed, them, a true reduction of the arsenals of each of the two countries, of: 13000 warheads with: 3500 for each part.

Country having the atomic bomb

Since 1945, year when the first bomb exploded with the New Mexico in the United States, several countries tried to control the design of such a weapon.

Country signatories holders of the NPT

Five countries are juridically recognized like “states equipped with the nuclear weapon” by the NPT, here their arsenal in March 2006:

the Russia: : 16000, of which: 5830 active;
the the United States: : 9962, of which: 5735 active;
the France: no public data is available, but several sources indicate approximately 350 heads, of which all or almost would be active;
the the United Kingdom: more than 200, a including little less than 200 active.
the Popular republic of China: approximately 200, including approximately 145 active;

The political economists indicate these five States by the term of “nuclear club”, which are also those who are permanent members of the Safety advice of the United Nations.

The North Korea is the only country which ratified the NPT, all in having acquired the nuclear weapon. The number of heads is estimated at less than one ten, of which some would be perhaps active. The North Korea carried out a nuclear test on October 9th, 2006.

Country not-signatories holders of the NPT

Three countries, not-signatories of the NPT, have the nuclear weapon:

the India: 40 to 50 heads, almost all active; carried out the May 18th 1974 its first nuclear test, officially with peaceful goal. The May 11th 1998, it carries out its first military test.
the Pakistan: 50 to 60, almost all active; carried out a few days after India, on May 28th, 1998, its first nuclear test.
Israel: would have nuclear weapons. A hundred would be active. According to a former technician of the Nuclear plant of Dimona, Mordechaï Vanunu, Israel would lay out of more than 200 atomic bombs. This declaration has was worth a judgment for espionage and treason to him and custodial sentence a 18 years. According to certain sources, Israel would have proceeded, with the assistance of the South Africa, with an underwater test in the Indian Ocean the September 22nd 1979, known under the name of the Incident Calved, but no certainty exists on this subject. The Israeli official position always was not to confirm nor to cancel the speculations relative to its possession of the atomic weapon. December 6th, 2006, Robert Spoil, American Secretary of State to defense declared during its hearing to the Senate: Iran is surrounded by countries equipped with the nuclear weapon: Pakistan in the east, Israel in the west… , a first for an American senior official. A few days later, on December 11th, 2006 during an interview of the German television channel N24 in connection with the Iranian nuclear ambitions, Ehud Olmert declared: Could you say that it is the same thing as for America, France, Israel and Russia? . It was obliged to correct the declaration of Robert Gates like his Lapsus and has to recall the position of Israel on the subject: Israel will not be the first country to introduce the nuclear weapon in the Middle East. It was our position, it is our position, that will remain our position. .

Country having a nuclear program of acquisition

Countries suspected of developing a military nuclear program

Country having dismantled their atomic installations

the South Africa which had a clandestine arsenal with seven heads in the Années 1980 dismantled this one with the whole beginning of the Années 1990.

the Suisse recommended to obtain an nuclear armament, built installations for uranium enrichment then contacted the Staff of the French Army to acquire a nuclear weapon before giving up the project in the middle of the Années 1960.

During the Years 1950 and 1960, the Sweden developed a secret program of nuclear weapon, in the objective to protect itself from a possible invasion of the Soviet Union. This program enabled him to produce an atomic bomb, but the program was abandoned in 1968, after the ratification of the NPT.

the Libya which officially gave up its nuclear program in 2003. It is the nine months result of secret negociations between Libya, the United States and Great Britain.

the Iraq stopped its nuclear program after the first war of the gulf. The United States and the United Kingdom suspected during a time that the program can be started again, but since the invasion of Iraq in 2003, no proof in this direction was found.

the new States resulting from dissolution from the Soviet Union, the such Ukraine and the Kazakhstan returned the warheads to Russia and dismantled the nuclear bases on their ground.

the French installations in Algérie were dismantled and the country did not lodge any nuclear weapon since its independence in 1962.

In the same way, the British base of nuclear tests in Australia was dismantled.

Various types of bombs

The nuclear weapons are of two types:

the weapons with fission or “bombs has”: they use a critical mass of Uranium enriched or Plutonium, joined together by the implosion of a traditional explosive.
weapons with fusion or bombs thermonuclear or “H-bombs”. The conditions of temperature and pressure necessary to the reaction of fusion of hydrogen isotopes (deuterium and tritium) are obtained by the explosion of a “starter” consisted a bomb with fission with plutonium.

The Bombe with neutrons is an alternative of thermonuclear bomb.

The powers of the nuclear bombs go the kiloton to the megaton of equivalent TNT. A nuclear explosion causes at the same time an effect of blast, a heating effect and radiations.

One distinguishes:

the Strategic nuclear weapon , instrument of the doctrines of nuclear deterrence or “not-employment”, intended to prevent a conflict,
of the nuclear weapon Tactical, or battle, likely to be employed on military objectives during a conflict. The precision of the vectors helping, this type of weapon led to the miniaturization and the low powers ( Minis-nuke in the American journalese).

Civil uses of the nuclear weapons were considered (digging of cavities for the storage of gas in particular) but ever implemented.

An operational nuclear warhead is associated with a vector, charged bringing it with on the target. These vectors are drawn missiles starting from air platforms (fighters), underwater or terrestrial (fixed or mobile), of the bombs released by plane, or of the artillery shells.

The bomb has

The bomb H

Tactic

Dice the years 1950, the two Superpuissance S developed a whole range of nuclear warheads to equip with many Vecteur S, in addition to traditional the bends released by plane, energy of the air-to-air Missile with the Torpille, while passing by mines and the shells of Artillerie.

The bomb with neutrons

Missiles Pluto and Hadès

The salted bomb

The radiological bomb

Minis-nukes

Effects of an atomic bomb

The breath

The power of the explosion is much more important than with a traditional explosive. A shock wave causes an important and fast displacement of the surrounding air, thus exerting a constraint (pressure) on the neighborhood objects.

The blast of the explosion destroys all the buildings around and causes lesions and the deafness of the people who are too close to the explosion. Once the shock wave passed, of strong winds created by the vacuum effect (depression, opposite constraint) due to the explosion, similar to those of a hurricane, finish demolishing the buildings which would be still upright.

If the explosion takes place on the level of the ground or even is underground, of the Séisme S can also take place.

Heat

The heat of the explosion is such as it starts fires and causes burns on the people close to the explosion. To give an order of magnitude, a bomb of ten megatons causes burns until in a radius of thirty kilometers and the temperature in its center reaches several million degrees. With that can be added burns to the eyes for those who look at the explosion.

The electromagnetic impulse (IEM)

Radiations

There are two great types of radiations:

those resulting directly from the explosion, which are very fatal and kill almost instantaneously (see Syndrome of acute irradiation);
those resulting from the dissemination of the radioactive elements of the bomb and the contaminated elements, which can be transported by the movements of air at very long distances. These irradiations cause many types of Cancer S, like Leucémie S and also cause malformations at the new ones born, following a deterioration of DNA of the parents or Fœtus. This form of irradiation is more the mortal in terms of many touched people.

The long-term effects are to be relativized according to the results of the medical monitoring of the survivors of Hiroshima and Nagasaki: there exists well an increase in the rates of cancers, significant, but less important than those related to other causes as the nicotinism (even for the subjects exposed to the strongest amounts the excess of cancer does not seem to exceed 4%). - Contrary to the generally accepted ideas: it was not observed of increase in malformations or genetic disorders at the descendants of irradiated survivors. ,

Climatic impact

Reference

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