Energy · 1958

Tokamak

A doughnut-shaped magnetic bottle becomes fusion's leading design.

Soviet physicists at the Kurchatov Institute built T-1 in 1958 on the ideas of Igor Tamm and Andrei Sakharov. T-3's 1968 results, confirmed by a British team, showed far better confinement than rivals, and tokamaks spread worldwide.

See it in the living tree Wikipedia

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1

Stellarator 1951

What it led to 3

Joint European Torus 1983
High-temperature superconducting magnet 2021
Long-pulse fusion plasmas 2025

Watch

What is a tokamak? And is a spherical tokamak different?Tokamak Energy · YouTube

Related measurements

The dashed line marks when it first worked.

Record fusion triple product Latest: 1.73×10²² keV·s/m³ (2017) Source: Wurzel & Hsu 2022, Physics of Plasmas 29, 062103; Wurzel & Hsu 2025 update, Physics of Plasmas 32, 112106

Nuclear electricity generation Latest: 2.81k TWh (2025) Source: Our World in Data