Plasma
The fourth state of matter — a superheated gas where atoms are stripped of their electrons. In fusion reactors, hydrogen isotopes are heated to 100+ million degrees Celsius, forming a plasma that enables fusion reactions.
Why It Matters
Confining and controlling plasma at extreme temperatures is the central engineering challenge of fusion energy.
Related Topics
Related Terms
Nuclear Fusion
The process of combining light atomic nuclei (typically hydrogen isotopes deuterium and tritium) to form heavier nuclei, releasing enormous energy. Fusion powers the sun but has not yet been achieved at commercial scale on Earth.
Tokamak
A donut-shaped (toroidal) device that uses powerful magnetic fields to confine hot plasma for nuclear fusion. The tokamak is the most developed approach to magnetic confinement fusion, used by ITER and SPARC.