What this document is, and how to read its numbers
This is a combined editorial. It gathers, in one volume, the two design studies Kronos Fusion Energy released in 2026 — a compact spherical-tokamak tritium/helium-3 breeder and a deuterium–helium-3 tandem-mirror generator — together with the intellectual-property estate, the people, and, in the internal edition, the full commercial case. The scientific text is the same text that appears in the arXiv preprints and the journal submissions; the editorial adds the apparatus a reader needs to hold the whole program at once, and nothing in the physics is altered to fit it.
The honesty stance is the asset
Every headline quantity carries an evidence class — Derived Recomputed Measured Requirement — and, where a number is a modelled extrapolation rather than a demonstrated value, it is labelled as such and its downside is shown next to it. Several quantities in the underlying corpus moved after first publication; where a value has been withdrawn or restated, the record says so plainly. This is deliberate: a diligence team will find the load-bearing assumptions, so the document surfaces them first.
- Title
- The Kronos Fleet — Hyperion · Aegis · MetroVolt: A Combined Design & Commercialization Study
- Author
- Priyanca Ford, Founder & CEO, on behalf of Kronos Fusion Energy
- Edition
- 2026 Combined Editorial · first issue
- Companion works
- The five-paper arXiv drop — (1) Breeder, (2) Burner, (3) REBCO magnet & tape, (4) Direct Energy Conversion, (5) AI/ML/Quantum control — with matching numbered Zenodo deposits, plus the IOP journal and IAEA-FEC submissions. Patents were filed before the drop.
- Naming
- Hyperion = the breeder; Aegis (defense) and MetroVolt (data-center) = one generator in two housings. Internal mode letters (D1, L) do not appear on public surfaces.
- Status
- Conceptual design & simulation study. Nothing herein is a construction commitment.
The fleet at a glance, and the way its numbers are marked
This volume opens with Orientation, presents the five research papers as a bound sequence, and closes with the Apparatus. Foundations sets out the three general results both machines rest on. Paper One is the Hyperion breeder; Paper Two the Aegis / MetroVolt generator; Papers Three, Four and Five are the enabling science — high-field REBCO magnets and tape, direct energy conversion, and the AI / ML / quantum control stack. A Digital Twin & 3-D Model part follows, then the Environmental profile. The Economics and levelized cost and the Business Case and diligence record appear in the internal edition only; the Simulations proof record and the Apparatus — patent portfolio, team, limitations, and sources — close both editions.
The fleet at a glance
| Hyperion | Aegis | MetroVolt | |
|---|---|---|---|
| Role | Strategic-isotope foundry | Defense installation power | Campus power |
| Machine | Spherical tokamak | Tandem mirror | Tandem mirror |
| Fuel | Deuterium–tritium | Deuterium–helium-3 | Deuterium–helium-3 |
| Delivers | Tritium · ³He · 14 MeV n | Resilient installation power | Firm campus power |
| Physics bar | Fusion gain only | Closure (gates named) | Closure + lunar ³He |
| In the fleet | Breeds the fuel | Proves the generator | Commercial destination |
How the numbers are marked
Every headline quantity carries an evidence class — Derived from first principles, Recomputed from raw data, Measured in hardware, or a Requirement yet to be met. Financial figures carry a case label and are confined to the internal (confidential) edition. Values that moved after first publication are shown as withdrawn or restated rather than quietly changed. A capability you can evaluate is one whose limits are on the page.
The Advanced-Fuel Scorecard — Physics, Not the Aneutronic Ideal
Fuel choice is the most consequential decision in a fusion program, and it is often made emotionally — toward the aneutronic ideal — rather than on the physics. We grade the four candidate fuels on one ruler: reactivity, temperature, neutron fraction, tritium logistics, availability, and demonstrated gain. No fuel wins on every axis. The Kronos architecture follows the scorecard, not the ideal: run deuterium–tritium where the product is the neutron and the bred material (the breeder), and deuterium–helium-3 (only 5.44% neutronic) where the product is power and neutrons are the liability (the burner) — with the helium-3 supply honestly lunar-gated.
Companion deposit (code & data, reproducible under CC BY 4.0): DOI 10.5281/zenodo.22132158 (v2 10.5281/zenodo.21746479) · Zenodo community kronos_fusion_energy.
Explore it live: interactive 3-D model · run the physics validator · companion film series (the deposited solvers, in the browser).
Table of Contents
Symbols, units, and the names of things
Fuel choice is the decision
Every fusion company implicitly picks a fuel, and the pick determines everything downstream: the neutron load, the tritium logistics, the required temperature, the conversion strategy. The choice is too often made emotionally — toward the aneutronic ideal — rather than on the physics. We grade all four candidate fuels on the same ruler and let the Kronos architecture fall out of the grades.
No fuel wins on every axis. Kronos runs deuterium–tritium where the product is the neutron and the bred material (the breeder) and deuterium–helium-3 where the product is power and neutrons are the liability (the burner, only 5.44% neutronic) — with helium-3 honestly lunar-gated. Proton–boron is not chosen.
The scorecard
The single most decisive axis is the neutron fraction of the fusion power — it sets the shielding, the activation, and whether the machine can sit near people and hardware. Deuterium–tritium is ~80% neutronic; deuterium–deuterium ~66%; deuterium–helium-3 only 5.44%, and even those neutrons come from an unavoidable D–D side reaction; proton–boron is effectively aneutronic at under 1%.
The Kronos reading of the scorecard
The architecture follows the grades rather than the ideal. Where the product is the neutron and the bred material — tritium, helium-3, isotopes, materials qualification — deuterium–tritium is correct, because its high neutron output is the whole point; this is the breeder. Where the product is power and neutrons are a liability to shield and a source of activation, deuterium–helium-3 is correct, because 5.44% is the lowest neutron burden among fuels with accessible reactivity; this is the burner.
Proton–boron is not chosen: its temperature, its radiation, and the absence of any demonstrated gain outweigh its aneutronic appeal today. And the one honest cost of the deuterium–helium-3 choice — fuel availability — is met by the breeder’s co-product helium-3 and, at fleet scale, lunar supply gated around 2038–40. The scorecard, not the aneutronic ideal, drew the architecture. Design rationale
The patent portfolio
The estate spans a granted high-field magnet patent, pending utility and 2026 provisional filings that map to the two products, a digital-twin control provisional, a registered trademark application, and the original 2022 provisional family. Every patentable disclosure in the five-paper arXiv drop was protected before publication: the breeder and burner provisionals were filed 1–2 August, and a publication-gap omnibus filing the evening before the drop swept up the DEC, plasma-control, and REBCO-winding matter of the three otherwise-unprotected papers. Patent numbers and application serials are matters of public record; claim scope is summarised, not reproduced.
Granted & pending utility
2026 provisional filings — mapped to the products
Trademark & origin
The narrow, defensible magnet novelty — the specific conductor and the digital-twin winding optimisation, not high-field REBCO as a category — is the commercial core that can earn ahead of any Q > 1 milestone, with markets in fusion magnet supply, MRI/NMR, accelerators, and proton therapy. The claim is scoped honestly: the high field is a system field result, not a stand-alone-coil record; the small-bore plug coil is structurally infeasible as a bare winding but resolved by a stress-managed structural shield (feasible-pending-FEA); and the winding-tape experiment returned a null result. The value is the method, not a field record.
Founding partners, board, advisors & auditors
Kronos is built by a bench of advanced-fuel-fusion, high-field-magnet, direct-conversion, and materials specialists, with a board and operations team drawn from defense, national laboratories, and industry. Dates are shown as ranges; where a tenure has ended or is term-ending, the range says so.
Founding Partners — Science
Board
Scientific Advisors
Scientific Auditors
Operations
Legal counsel is retained; those roles are held on the internal roster and are not listed here.
List of Figures
Sources
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[2] A. S. Richardson, NRL Plasma Formulary, Naval Research Laboratory (2019).
[3] I. E. Ochs, E. J. Kolmes, and N. J. Fisch, “Bremsstrahlung and the electron–electron contribution in fusion plasmas,” Physics of Plasmas (2024).
[4] T. H. Rider, “Fundamental limitations on plasma fusion systems not in thermodynamic equilibrium,” Physics of Plasmas 4, 1039 (1997).
[5] ITER Physics Expert Groups, “ITER Physics Basis,” Nuclear Fusion 39, 2137 (1999).
[6] N. A. Uckan and J. Sheffield, “Tokamak scaling and confinement,” in Tokamak Concept Improvement, IAEA (1989).
[7] O. Sauter, C. Angioni, and Y. R. Lin-Liu, “Neoclassical conductivity and bootstrap current,” Physics of Plasmas 6, 2834 (1999).
[8] F. Troyon et al., “MHD limits to plasma confinement,” Plasma Physics and Controlled Fusion 26, 209 (1984).
[9] J. P. Freidberg, Plasma Physics and Fusion Energy, Cambridge University Press (2007).
[10] R. F. Post, “The magnetic mirror approach to fusion,” Nuclear Fusion 27, 1579 (1987).
[11] D. E. Baldwin, “End-loss processes from mirror machines,” Reviews of Modern Physics 49, 317 (1977).
[12] T. K. Fowler, R. W. Moir, and T. C. Simonen, “A new simpler tandem mirror,” Nuclear Fusion 57, 056014 (2017).
[13] G. L. Kulcinski and J. F. Santarius, “Advanced fuels and the D–3He cycle,” University of Wisconsin Fusion Technology Institute.
[14] W. L. Barr and R. W. Moir, “Test results on direct energy converters for mirror reactors,” Nuclear Technology/Fusion 3, 98 (1983).
[15] D. B. Go et al., “Thermionic energy conversion in the twenty-first century,” Frontiers in Mechanical Engineering 3, 13 (2017).
[16] M. Wang et al., “The AME 2020 atomic mass evaluation,” Chinese Physics C 45, 030003 (2021).
[17] J. E. Menard et al., “Fusion nuclear science facilities and pilot plants based on the spherical tokamak,” Nuclear Fusion 56, 106023 (2016).
[18] A. J. Creely et al., “Overview of the SPARC tokamak,” Journal of Plasma Physics 86, 865860502 (2020).
[19] T. P. Wright, “Factors affecting the cost of airplanes,” Journal of the Aeronautical Sciences 3, 122 (1936).
[20] U.S. Department of Energy / NNSA, Stockpile Stewardship and Management Plan, FY2024.
[21] J. F. Santarius, G. L. Kulcinski, and L. A. El-Guebaly, “A strategy for D–3He fusion energy development,” Journal of Fusion Energy 17, 33 (1998).
[22] M. A. Abdou et al., APEX advanced blanket concepts, Fusion Engineering and Design (1999–2003).
[23] Federal Register, notice on supply of tritium to non-federal entities (1999).
[24] Kronos Fusion Energy, “Simulation register and reproducibility deposit,” Zenodo (2026).
[25] A. O. Thome et al., “ELM-free negative-triangularity edge on DIII-D,” Plasma Physics and Controlled Fusion (2024), doi:10.1088/1361-6587/ad6f40.
[26] T. Eich et al., “Scaling of the tokamak near scrape-off layer power width,” Nuclear Fusion 53, 093031 (2013).
[27] J. Lim et al., “Scrape-off-layer width in negative-triangularity plasmas,” Nuclear Fusion / Plasma Physics and Controlled Fusion (2023).
[28] A. O. Nelson et al., “Prohibition of second-stability access at negative triangularity,” Plasma Physics and Controlled Fusion 64, 124002 (2022).
How this document was made
The Kronos Fleet — Combined Editorial, 2026 is set in Fraunces (display), Gelasio (text), and IBM Plex Mono (data & equations), carried forward from the Kronos editorial design system.
The figures are rendered at 300 dpi from the deposited generator scripts; the document is composed as a single self-contained file with embedded fonts and imagery, paginated to US Letter, and rendered to PDF through a headless Chromium engine in matched light and dark editions.
Every headline quantity carries an evidence class; withdrawn and restated values are marked as such. Nothing herein is frozen beyond the founder-approved Tier-A set.
Explore it live — turn the interactive 3-D model, run the deposited solvers in the physics validator, and watch the companion film series.
Notice, status, and distribution
Conceptual design & simulation study. This document reports a conceptual design and simulation study. It is not a construction commitment, a safety-analysis report, a regulatory filing, or an offer of securities. Forward-looking statements — schedules, costs, market sizes, and performance — are estimates subject to the limitations set out in the Simulations part and may change.
Numbers and their classes. Quantities are reported with evidence classes and case labels; modelled, assumed, and requirement-class values are identified as such and are not to be quoted without their labels.
Public edition. This edition carries the physics and design only; all financial, funding, and defense-commercial content has been removed for public distribution. The scientific text corresponds to the arXiv and journal submissions.
© 2026 Kronos Fusion Energy. All rights reserved. Hyperion, Aegis, and MetroVolt are product designations of Kronos Fusion Energy.
One programme, in five papers
This editorial is one of five that together describe the Kronos fusion programme — a breeder that funds a generator, and the magnet, conversion, and control science that enable both. Each is published open-access with a reproducible companion deposit.
Explore the whole programme live: the interactive 3-D model, the in-browser physics validator, and the companion film series.