30%
Technological maturity
- Plasma parameters and energy gain achieved12%
- Maturity of key technologies: magnets, drivers, blanket, tritium10%
- Credibility of the path to a power plant8%
Fusion Index methodology
The Fusion Index 2026 combines fourteen indicators into five weighted pillars; their weighted sum gives the overall score. This page explains how scores and ranks come about and where their limits lie.
The association collects no data. Each pillar is assessed by the editorial team on a scale from 0 to 100; the indicators describe what that assessment is guided by. The values are therefore expressions of opinion, not measurement results.
20%
Research environment
- Scientific reputation8%
- Funding7%
- Staff and infrastructure5%
25%
Research quality
- Scientific impact of publications10%
- Experimental milestones10%
- Disclosure and peer review of results5%
10%
International networking
- International collaborations5%
- Contributions to large projects and programmes5%
15%
Transfer and society
- Industrial value creation and supply chains6%
- Patents and spin-offs4%
- Public and political impact5%
Calculation
The overall score is the weighted mean of the pillars. If a pillar cannot be assessed, the remaining weights are scaled up proportionally. The scale is fixed: 100 stands for what the editorial team considers the world-leading level, 0 for nothing noteworthy being discernible in a pillar.
Ties after rounding to one decimal place share the same rank, prefixed with “=”. From rank 51, ranks are grouped in bands of ten, because finer gradations would suggest a precision that an editorial assessment does not have.
Eligibility criteria
An entry in the Fusion Index is ranked if it
- works on fusion energy – through research, development, building or operating a facility, or through advocacy,
- documents its activity in a publicly traceable way and
- can be assessed in at least three of the five pillars.
Entries that do not meet the criteria remain listed, but without a rank.
Disclaimer
This index is an editorial assessment by the Bundesverband für Kernfusion e.V. and not a neutral evaluation. Scores and ranks are subjective expressions of opinion by the editorial team.
The position of an entry supports no statement about the scientific quality, the economic viability or the prospects of success of the organisation named. Different types of organisation pursue different goals and are comparable only to a limited extent.
As an organisation with an interest in nuclear fusion, the Bundesverband für Kernfusion e.V. is itself listed in this index. This involvement is disclosed here.
The association accepts no liability for correctness, completeness or currency. Please report any errors to info@kernfusion.eu.