WEST
WEST is a tokamak fusion device run by CEA in France. It is operating. Like every fusion device built so far, it has produced no net electricity.
Held a plasma for 1,337 seconds, over 22 minutes, with 2.6 GJ of injected energy, the longest tokamak plasma anywhere. It is a fully tungsten-walled machine, which is the material ITER will use and the reason the result matters beyond the duration itself.
Built inside the vessel of the older Tore Supra at Cadarache, a few kilometres from the ITER site. Long pulses in a tungsten environment are exactly the problem ITER has to solve, and WEST exists to solve it first at smaller scale. Duration records are not energy records: WEST puts far more energy in than it gets out, as every device on this page does.
| Organisation | CEA |
|---|---|
| Approach | tokamak |
| Confinement | magnetic |
| Country | France |
| Status | Operating |
| First plasma | 2016 |
| Target date | none stated |
|---|---|
| Power target | none stated |
| Energy gain target | none stated |
| Net electricity | No. no fusion device has produced any |
Other tokamak projects
Fusion needs tritium, and the world's civilian stock comes mostly from CANDU fission reactors. See the fusion overview.
WEST in context
14 of the 24 fusion projects on record use the tokamak approach: 7 operating, 3 under construction, 3 planned and 1 closed.
Its first plasma is dated 2016, 10 years ago: the 9th earliest of 15 projects on record with a first-plasma date.
| Measure | WEST | Median of all projects | Standing |
|---|---|---|---|
| First plasma | 2016 | 2015 | 9 of 15 (earliest first) |
Worked out from the entries on this site only, so a figure compares WEST with what is recorded here, not with everything that exists. An entry with no value for a measure is left out of that measure's ranking and median.
Sources
- NucNet, France tokamak sets plasma record · retrieved 2026-09-07
How these sources are used, including the corrections applied on top of them and what is deliberately left blank · download the underlying data