tokamak

American  

[toh-kuh-mak, tok-uh-] / ˈtoʊ kəˌmæk, ˈtɒk ə- /

noun

Physics.

1. a type of experimental nuclear fusion reactor in which a plasma of atoms circulates in a toroidal tube and is confined to a narrow beam by an electromagnetic field.

---

tokamak British  

/ ˈtɒkəˌmæk /

noun

1. physics a toroidal reactor used in thermonuclear experiments, in which a strong helical magnetic field keeps the plasma from contacting the external walls. The magnetic field is produced partly by current-carrying coils and partly by a large inductively driven current through the plasma

---

Etymology

Origin of tokamak

1960–65; < Russian tokamák, acronym from toroidálʾnaya kámera s aksiálʾnym magnítnym pólem toroidal chamber with an axial magnetic field

---

Example Sentences

See Examples For:

tokamak

Researchers demonstrated PACMAN's flexibility in five experiments using the DOE's DIII-D National Fusion Facility tokamak in San Diego.

From Science Daily ● Sep. 6, 2026

Well, if the design works, the twists and turns of a stellarator make the burning hot plasma easier to control than in the rival tokamak design, says Sciortino.

From BBC ● Apr. 20, 2026

A common approach to fusion is to build a tokamak.

From BBC ● Apr. 20, 2026

Despite this advantage, tokamak experiments have long been constrained by an upper density limit.

From Science Daily ● Jan. 4, 2026

China has invested heavily in its own tokamak program, achieving record plasma temperatures and confinement times.

From The Wall Street Journal ● Dec. 28, 2025

Random Word

Spin the wheel and learn a new word!

---