WEST (formerly Tore Supra)

43°42′13″N 5°45′54″E / 43.703626°N 5.764968°E / 43.703626; 5.764968

The WEST, or Tungsten (chemical symbol "W") Environment in Steady-state Tokamak, (formerly Tore Supra) is a French tokamak that originally began operating as Tore Supra after the discontinuation of TFR (Tokamak of Fontenay-aux-Roses) and of Petula (in Grenoble). The original name came from the words torus and superconductor, as Tore Supra was for a long time the only tokamak of this size with superconducting toroidal magnets, allowing the creation of a strong permanent toroidal magnetic field. After a major upgrade to install tungsten walls and a divertor, the tokamak was renamed WEST (the name alludes to EAST, another tokamak).

WEST is situated at the nuclear research center of Cadarache, Bouches-du-Rhône in Provence, one of the sites of the Commissariat à l'Énergie Atomique. Tore Supra operated between 1988 and 2010. Its goal was to create long-duration plasmas. The upgrade to WEST took place between 2013 and 2016. WEST has been operating since 2016.

Tore Supra long held the record for the longest plasma duration time for a tokamak, at 6 minutes 30 seconds. With over 1000 MJ of energy injected and extracted in 2003, and it allowed researchers to test critical parts of equipment such as plasma facing wall components or superconducting magnets that will be used in its successor, ITER. As ITER faced long delays, WEST remained in operation and on 12 February 2025, it set a new record for duration at 22 minutes and 17 seconds, while operating at lower temperatures.