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a device consisting of a supply of nuclear energy, locked within certain substances, and the equipment for the rapid release of the energy to set off a nuclear explosion.
There are two types of nuclear charges: atomic and hydrogen. The action of the first type (atomic bomb) is based on the release of nuclear energy upon the fission of certain heavy nuclei (235U or 239Pu; see). The action of the second type (hydrogen bomb) is based on the thermonuclear reaction of the fusion of helium nuclei from lighter nuclei (deuterium, tritium, or their mixtures with 6Li), in the course of which approximately four times the energy is released than upon the decay of the same amount of fissionable material (seeTHERMONUCLEAR REACTION).
Nuclear charges with a power ranging from a few kilotons to several tens of megatons of TNT equivalent have been tested. The power of a nuclear charge is determined both by the amount of fissionable material or hydrogen isotopes contained in the charge and by the design aspects that create the conditions in which the maximum amount of material is brought together to initiate a nuclear reaction. An important element in the design of a nuclear charge is the initiating charge, which creates supercritical conditions for the fissionable material in an atomic charge, and the required temperature in a hydrogen charge (in the latter case, an atomic charge is used as the initiating charge). Structurally, the nuclear charge is enclosed in a steel casing; its total mass together with the detonation devices usually ranges from a few hundred kg to several metric tons. When it is used as a nuclear weapon, it is incorporated into an aerial bomb, the nuclear warhead of a missile, a torpedo, or other projectile for delivery to the target.
Nuclear charges are also used for peaceful purposes, for example, in various large-scale blasting operations and in the mining of minerals.