ST80-HTS was announced in 2022 as Tokamak Energy's next high-field HTS spherical tokamak, to be built at Culham with completion planned for 2026 as a step to a pilot plant. No construction progress has been reported, and in 2026 the company said it will not build its own pilot plant, focusing on HTS magnets and the STEP partnership.
New to fusion? Nuclear fusion, explained: three ways to bottle a star
Current state
| Status | Design |
| Country | United Kingdom |
| Location | UKAEA Culham Campus, Oxfordshire |
| Developer | Tokamak Energy |
| Developer type | Private |
| Concept | Spherical tokamak |
| Purpose | Demonstration |
| First plasma target | 2026 |
| Site | Site at UKAEA Culham Campus announced 2022/23; no construction reported |
| Private funding raised | USD 335m (as of 2024-11) |
Notes
Status kept as "Design" because no formal cancellation of ST80-HTS was found; community reports describe it as on hold pending funding. The 2026 first-plasma target is stale and almost certainly missed. GOV.UK announcement date given as 2023 (year only verified loosely).
Timeline
- 2022-10 — Tokamak Energy announced ST80-HTS, an advanced HTS spherical tokamak prototype with build completion planned for 2026. (source)
- 2023 — The UK government announced ST80-HTS would be built at UKAEA's Culham Campus. (source)
- 2026-08-18 — Tokamak Energy said it will not go on to construct its fusion pilot plant itself. (source)
The timeline is append-only: corrections are added as new entries. Stated targets appear in the current-state table, never as milestones.
Related projects
- CTRFR-1 / Startorus No.1 (Startorus Fusion) Design · China
- JET (Joint European Torus) Shut down · United Kingdom
- Machine 4 (First Light Fusion) Cancelled · United Kingdom
- MAST Upgrade Operating · United Kingdom
- ST40 (Tokamak Energy) Operating · United Kingdom
- STEP Fusion (West Burton) Design · United Kingdom
See all 51 projects in the Fusion Energy Companies & Projects Tracker →
Sources
- Tokamak Energy announces ST80-HTS advanced prototype — PR Newswire / Tokamak Energy (primary), checked 2026-10-11
- Tokamak Energy's fusion prototype to be built at UKAEA's campus — GOV.UK (primary), checked 2026-10-11
- Articles tagged Tokamak Energy — ANS Nuclear Newswire, checked 2026-10-11
- Tokamak Energy's 'Focus Collection' featured in Nuclear Fusion journal — Tokamak Energy (primary), checked 2026-10-11