Fusion Reactor Patent Landscape 2026
Fusion Reactor Patent Landscape in 2026
The Regents of the University of California dominates a concentrated field, holding 150 patent records against a corpus of 214 patent families, with the United States as the primary filing jurisdiction. Activity peaked around 2021 and has plateaued near that level, signaling a maturing field where early structural positions are increasingly entrenched.
University of California leads a highly concentrated field
The University of California (Board of Regents) holds the commanding position in fusion reactor patenting, accumulating 150 patent records — more than double the nearest rival, the University of Florida Research Foundation with 60. This gap reflects years of sustained, focused investment in field-reversed configuration and plasma-confinement approaches.
The top five filers — University of California, University of Florida Research Foundation, Hitachi, Toshiba, and Southwestern Institute of Physics — together account for 42% of the combined patent records of the hundred largest filers. The tier gap between first and second place is especially pronounced, suggesting a two-tier structure: one dominant academic leader and a set of institutional challengers separated by a wide margin.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | Regents of the University of California | 150 | |
| 2 | University of Florida Research Foundation Inc. | 60 | |
| 3 | Hitachi Ltd. | 43 | |
| 4 | Toshiba Corporation | 27 | |
| 5 | Southwestern Institute of Physics | 21 | |
| 6 | Hefei Institute of Physical Science, Chinese Academy of Sciences | 19 | |
| 7 | NuScale Power LLC | 18 | |
| 8 | Doryokuro Kakunenryo Kaihatsu Jigyodan (Power Reactor and Nuclear Fuel Development Corporation) | 16 | |
| 9 | SU N Energy Holdings Ltd. | 16 | |
| 10 | UK Atomic Energy Authority | 15 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | Suneel Navnitdas Parekh | 13 | |
| 12 | Ellwood Sutherland Cook | 12 | |
| 13 | Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) | 11 | |
| 14 | Soletanche Freyssinet SAS | 10 | |
| 15 | United States Department of Energy | 10 | |
| 16 | Japan Atomic Energy Research Institute | 10 | |
| 17 | NGK Insulators Ltd. | 10 | |
| 18 | European Atomic Energy Community (Euratom) | 10 | |
| 19 | HB11 Energy Holdings Pty Ltd. | 9 | |
| 20 | Alset Tech | 9 |
The leaders’ positions imply that any new entrant or mid-tier player seeking to challenge the core fusion-reactor and plasma-confinement space will face substantial prior-art density. Differentiation via adjacent technology routes — materials, radiation shielding, or power-conversion systems — represents a more navigable entry path.
Filings from approximately 2024 onward are subject to publication lag and likely under-represent actual recent activity; trend conclusions for that period should be treated as provisional. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Annual activity has plateaued near its 2021 peak; core IPC classes dominate
Two charts together capture the pace of invention and the technology mix: the annual filing trend reveals where the field is in its cycle, while the IPC composition shows which technical branches attract most attention and which remain sparse.
Annual filing trend
Filings climbed from 13 records in 2017 to a peak of 38 in 2021, then eased to 31 in 2022 and 26 in 2023. The 2024–2026 bars are suppressed by publication lag and should not be read as a continuation of the post-peak decline. The overall pattern is consistent with a maturing field: rapid early growth followed by stabilisation near the peak rather than a sharp contraction.
↗ Hover for values · click a bar to ask EurekaTechnology composition
The three core IPC classes — G21B (Fusion reactors), G21C (Nuclear reactors), and G21D (Nuclear power plants) — each carry roughly 390–400 patent records, forming an overwhelmingly dominant core. H05H (Plasma and particle accelerators, 190 records) is the next significant cluster. Classes such as H01J (Electron and discharge tubes, 80), C22C (Alloys, 74), and G21G (Conversion of nuclei, 50) are materially smaller, pointing to under-served adjacent branches where coverage is thinner relative to the core.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
Power generation system and power generation method
A power generation system comprises: a muon-catalyzed nuclear fusion device configured to undergo muon-catalyzed nuclear fusion; and a nuclear-reactor power generation device configured such that a nuclear fuel therein is irradiated with neutrons generated as a result of muon-catalyzed nuclear fusion in the muon-catalyzed nuclear fusion device, thereby to… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | Controlled fusion in a field reversed configuratio… | 157 |
| 2 | Energy amplifier for nuclear energy production dri… | 126 |
| 3 | 涂层无机纤维增韧MAX相陶瓷复合材料、其制备方法及用途 | 111 |
| 4 | Formation of a field reversed configuration for ma… | 109 |
| 5 | Formation of a field reversed configuration for ma… | 100 |
| 6 | Controlled fusion in a field reversed configuratio… | 79 |
| 7 | System for and method of producing and retaining t… | 79 |
| 8 | Formation of a field reversed configuration for ma… | 76 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the structure means for R&D strategy
Four structural observations — maturity stage, concentration dynamics, collaboration patterns, and geographic reach — together define the strategic terrain for new and existing players.
Field is at plateau, not in decline
The lifecycle stage is Maturity: annual filings peaked around 2021 and have since plateaued near that level rather than growing further. On a multi-year basis the field is still active, but the era of rapid volume expansion has passed. R&D investment must now justify itself through quality and differentiation rather than riding a broad wave of filing growth.
Plateau · post-2021 peakOne dominant player, a thin second tier
The top five filers hold 42% of the hundred largest filers’ combined records, and the gap between rank 1 (150 records) and rank 2 (60 records) is stark. This level of concentration means the core plasma-confinement design space is well-defended. Challengers ranked 3–10 each hold between 15 and 43 records, clustering into a thin second tier that has not yet closed on the leader.
HHI-style concentrationOne dominant co-filing pair; ecosystem otherwise fragmented
The University of California and the University of Florida Research Foundation co-filed 57 patent records together — by far the most active pairing in the corpus and reflecting the long-running TAE Technologies / field-reversed-configuration program. Downstream pairings are much smaller: Doryokuro Kakunenryo Kaihatsu Jigyodan with Kawasaki Steel (6 co-filings), and Toshiba with Japan Atomic Energy Research Institute (2). Outside these clusters, the co-filing network is sparse, suggesting limited cross-institutional collaboration at scale.
Academic-led co-filingUS-centric filing; Japan and Europe as secondary hubs
The United States is the dominant filing jurisdiction with 201 patent records, reflecting both the location of the leading applicants and the strategic importance of US market protection. Japan (120) and Europe via the EPO (106) form a clear second tier, followed by China (75) and WIPO PCT (67). South Korea (17), Canada (32), and the UK (28) round out coverage. The broad multi-jurisdiction footprint of leading applicants signals serious commercialisation intent rather than purely academic filing.
US-first, JP/EP secondaryGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| Regents of the University of California | University of Florida Research Foundation Inc. | 57 |
| Doryokuro Kakunenryo Kaihatsu Jigyodan (Power Reactor and Nuclear Fuel Development Corporation) | Kawasaki Steel Corporation | 6 |
| Toshiba Corporation | Japan Atomic Energy Business Corporation | 5 |
| Toshiba Corporation | Japan Atomic Energy Research Institute | 2 |
| Southwestern Institute of Physics | Shenyang Huiyu Vacuum Technology Co., Ltd. | 2 |
| Hefei Institute of Physical Science, Chinese Academy of Sciences | Hefei CAS IDEAL Robot Technology Co., Ltd. | 2 |
| Toshiba Corporation | Central Research Institute of Electric Power Industry | 1 |
| Toshiba Corporation | Toshiba Engineering Corporation | 1 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
University of California leads; Chinese institutions are new entrants gaining ground
The top two positions are held by US academic institutions with overlapping technology focus, reflecting a long-running research partnership. Below them, Japanese industrials, Chinese research institutes, and private-sector challengers occupy a fragmented second tier.
University of California (Board of Regents)
The University of California holds 150 patent records, concentrated in G21B (Fusion reactors), G21D (Nuclear power plants), and H05H (Plasma and particle accelerators) — each carrying approximately 143–145 records under this applicant. Its momentum trend is listed as a new entrant in the most recent filing window, which likely reflects reclassification or a quiet recent period; the overall portfolio remains by far the largest in the corpus.
patent records: 150Southwestern Institute of Physics
Southwestern Institute of Physics holds 21 patent records with a technology focus on G21C (Nuclear reactor instrumentation and monitoring) and G21B (Fusion reactors), complemented by G06F (digital data processing), suggesting growing investment in simulation and digital twins for fusion diagnostics. Its momentum trend is classified as a new entrant in the recent window, making it one of the more active emerging institutional players alongside Hefei Institute of Physical Science.
patent records: 21| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| Regents of the University of California | 2 | ▲ new entrant |
| Southwestern Institute of Physics | 6 | ▲ new entrant |
| Hefei Institute of Physical Science, Chinese Academy of Sciences | 6 | ▲ new entrant |
| SU N Energy Holdings Ltd. | 3 | ▼ -75% |
| UK Atomic Energy Authority | 2 | ▼ -82% |
Under-served branches adjacent to the dominant fusion core
Several IPC classes sit materially below the dominant G21B/G21C/G21D core in record count and share, representing areas where the patent landscape is less densely mapped relative to their technical relevance to fusion systems.
C22C · Alloys for fusion-grade structural materials
With 74 patent records and a 3% share of the IPC distribution, alloy development for fusion-grade structural applications is notable given the extreme neutron flux and thermal environments inside a fusion reactor. Hitachi holds a leading position here (33 records under C22C 38), suggesting industrial players have begun staking claims, but the broader field remains sparse relative to the core plasma classes. Entry paths include reduced-activation ferritic-martensitic steels and oxide-dispersion-strengthened alloys, where materials science expertise can be differentiated from the plasma-physics core.
Search this in Eureka →G21F · Radiation protection and shielding
G21F carries only 36 patent records and a 2% share, which is notably low given that tritium management, neutron shielding, and first-wall protection are critical engineering challenges for any commercial fusion plant. The relative sparsity suggests most applicants have focused patent activity on confinement and plasma physics rather than the balance-of-plant engineering. Teams with expertise in shielding materials, blanket design, or tritium breeding could find less crowded ground here, provided they can demonstrate direct fusion-plant relevance.
Search this in Eureka →How leaders differ by technology route
Strength of each leader across the main technology routes.
| Player | G21B 1 · Fusion reactors | G21D 7 · Nuclear power plants | H05H 1 · Plasma & particle accelerators | G21C 3 · Nuclear reactors | G21C 1 · Nuclear reactors |
|---|---|---|---|---|---|
| Regents of the University of California | Strong · 145 | Strong · 145 | Strong · 143 | Absent | Absent |
| University of Florida Research Foundation Inc. | Strong · 57 | Strong · 57 | Strong · 57 | Absent | Absent |
| Hitachi Ltd. | Strong · 23 | Absent | Absent | Strong · 27 | Absent |
| Japan Atomic Energy Research Institute | Strong · 13 | Absent | Strong · 7 | Absent | Absent |
| Ellwood Sutherland Cook | Absent | Absent | Absent | Strong · 9 | Strong · 10 |
| UK Atomic Energy Authority | Strong · 9 | Absent | Absent | Strong · 9 | Absent |
| Lin Ping Wha | Strong · 8 | Strong · 8 | Absent | Absent | Absent |
Frequently asked questions
The evidence set covers 214 patent families in scope. This corpus spans multiple jurisdictions, with the United States as the primary filing office.
The Regents of the University of California is the top filer with 150 patent records, more than double the second-ranked University of Florida Research Foundation at 60 records. Their portfolio concentrates on fusion reactors (G21B), nuclear power plants (G21D), and plasma and particle accelerators (H05H).
The field is at the Maturity stage. Annual filings peaked around 2021 at 38 records and have since plateaued near that level. This indicates the period of rapid filing growth has passed, though activity remains substantial on a multi-year basis.
The United States leads with 201 patent records, followed by Japan (120), Europe via the EPO (106), China (75), and WIPO PCT (67). Canada (32), the United Kingdom (28), and Germany (22) represent secondary protection markets.
G21F (Radiation protection and shielding, 36 records, 2% share) and C22C (Alloys, 74 records, 3% share) are the most technically relevant adjacent branches with materially lower filing density compared to the G21B/G21C/G21D core. G21G (Conversion of nuclei, 50 records) is also relatively sparse.
The most active co-filing pair is the University of California and the University of Florida Research Foundation, with 57 jointly filed patent records — a relationship associated with the field-reversed configuration program. Other collaboration pairs, such as Doryokuro Kakunenryo Kaihatsu Jigyodan with Kawasaki Steel (6 co-filings) and Toshiba with Japan Atomic Energy Research Institute (2), are considerably smaller. The co-filing network is otherwise fragmented.
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Disclaimer. This page is generated from PatSnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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