Nuclear physics

Deuterium

A heavy isotope of hydrogen with one neutron, used as fusion fuel in thermonuclear weapons.

Deuterium occurs naturally at about 1 atom per 6,420 of normal hydrogen. In thermonuclear weapons, lithium-6 deuteride (a solid compound) is the fusion fuel — neutron irradiation of the lithium produces tritium in situ, which then fuses with deuterium to release energy.

Related terms

See the full Nuclear Weapons Glossary.