Wiktionary
n. A weapon whose power is derived from nuclear fusion at high temperature
Wikipedia
A thermonuclear weapon is a nuclear weapon that uses the energy from a primary nuclear fission reaction to compress and ignite a secondary nuclear fusion reaction. The result is greatly increased explosive power when compared to single-stage fission weapons. It is colloquially referred to as a hydrogen bomb or H-bomb because it employs fusion of isotopes of hydrogen. The fission stage in such weapons is required to cause the fusion that occurs in thermonuclear weapons.
The first full scale thermonuclear test was done by the United States in 1952; the concept has since been employed by most of the world's nuclear powers in the design of their weapons. The modern design of all thermonuclear weapons in the United States is known as the Teller–Ulam configuration for its two chief contributors, Edward Teller and Stanislaw Ulam, who developed it in 1951 for the United States, with certain concepts developed with the contribution of John von Neumann. Similar devices were developed by the Soviet Union, United Kingdom, China, and France.
As thermonuclear weapons represent the most efficient design for weapon energy yield in weapons with yields above , virtually all the nuclear weapons deployed by the five nuclear-weapon states under the NPT today are thermonuclear weapons using the Teller–Ulam design.
The radiation implosion mechanism is a heat engine that exploits the temperature difference between the secondary stage's hot, surrounding radiation channel and its relatively cool interior. This temperature difference is briefly maintained by a massive heat barrier called the "pusher", which also serves as an implosion tamper, increasing and prolonging the compression of the secondary. If made of uranium, as is almost always the case, it can capture neutrons produced by the fusion reaction and undergo fission itself, increasing the overall explosive yield. In many Teller–Ulam weapons, fission of the pusher dominates the explosion and produces radioactive fission product fallout.
Usage examples of "thermonuclear weapon".
The Soviet Union launched Sputnik 1, exploded their first thermonuclear weapon, and successfully tested the first intercontinental ballistic missile (almost a year ahead of the United States).
Since there is no theoretical upper limit to the explosive yield of a thermonuclear weapon, there seem to be those in the weapons laboratories who consider making bigger bombs not only as a stirring challenge, but also as a way to mute pesky environmentalists by securing a seat for nuclear weapons on the save-the-Earth bandwagon.
It called for the placement of a limited thermonuclear weapon at the site of exposure of terrestrial life to exogenous organisms.
Even a thermonuclear weapon would have been pointless in an object travelling at .
Some military type, having too much gusto, decided that it wouldn't hurt to lob a thermonuclear weapon into one of the predicted probability areas, provided it was unsuitable for anything else.