Weapons & delivery systems

Hydrogen Bomb

A nuclear weapon that derives most of its energy from nuclear fusion of hydrogen isotopes, ignited by a fission primary stage.

Also called thermonuclear or H-bombs, hydrogen bombs use a small fission bomb to compress and heat a fusion fuel (typically lithium deuteride) to fusion-ignition conditions. Yields are scalable to tens of megatons; the largest weapon ever tested, Tsar Bomba (1961), was a 50 Mt three-stage thermonuclear device. Modern strategic warheads are all thermonuclear.

Related terms

See the full Nuclear Weapons Glossary.