thermonuclear warhead

A thermonuclear warhead is an explosive device that derives its destructive power from nuclear fusion—the same process that powers the sun.

Unlike simpler atomic bombs that rely on fission alone, thermonuclear weapons use a fission explosion to trigger fusion of hydrogen isotopes, producing vastly greater yields.

These are the warheads mounted on intercontinental ballistic missiles: Each submarine carries multiple thermonuclear warheads.

Also called a hydrogen bomb or H-bomb when referring to the weapon generally.