to·​ka·​mak ˈtō-kə-ˌmak How to pronounce tokamak (audio) ˈtä- How to pronounce tokamak (audio)
variants or less commonly tokomak
: a toroidal device for producing controlled nuclear fusion that involves the confining and heating of a gaseous plasma by means of an electric current and magnetic field

Examples of tokamak in a Sentence

Recent Examples on the Web In a tokamak or a stellarator, the hot plasma is limited to a density of 10 14 deuterons per cubic centimeter. Bayarbadrakh Baramsai, IEEE Spectrum, 27 Feb. 2022 An animation showing how tokamaks generate nuclear fusion energy. Angela Dewan, CNN, 8 Feb. 2024 In the 1950s, scientists created various magnetic-confinement fusion devices, the most well known of which were Andrei Sakharov’s tokamak and Lyman Spitzer’s stellarator. Bayarbadrakh Baramsai, IEEE Spectrum, 27 Feb. 2022 For more than 70 years, fusion research has largely focused on mimicking the inside of the sun in reactors known as tokamaks, which trap superhot hydrogen gas within strong magnetic fields so that atoms will collide and fuse. Kenneth Chang, New York Times, 13 Nov. 2023 Magnetic confinement uses electromagnets to confine plasma, typically inside a tokamak. IEEE Spectrum, 15 July 2023 But with a tokamak, touching the side triggers an immediate reaction that can take the whole tokamak offline in an instant. Caroline Delbert, Popular Mechanics, 13 Sep. 2022 Working in conjunction with the federal government, the company operates the DIII-D National Fusion Facility, which houses the largest tokamak in the United States. Rob Nikolewski, San Diego Union-Tribune, 14 Aug. 2023 That includes, in the 1980s, a class of materials that exhibited superconductivity above the boiling point of liquid nitrogen (–196 degrees C), making way for all sorts of applications, from magnetic resonance imagery to tokamaks for nuclear fusion. WIRED, 2 Aug. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'tokamak.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Russian, from toroidal'naya kamera s aksial'nym magnitnym polem (toroidal chamber with an axial magnetic field)

First Known Use

1965, in the meaning defined above

Time Traveler
The first known use of tokamak was in 1965

Dictionary Entries Near tokamak

Cite this Entry

“Tokamak.” Dictionary, Merriam-Webster, Accessed 4 Mar. 2024.

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