KRONOS FUSION ENERGY WHITEPAPER LIBRARY
Design & Physics Series · 104 papers
The Kronos Whitepaper Library
A library of short papers on the Kronos design and its low-neutron fuel cycle — the
Hyperion breeder, the Aegis and MetroVolt burner, and the method that ties them together. Every paper
leads with the physics, names its gates, and traces to deposited data and code. No economics, no
forecasts — design and low-neutron, on the record.
Three machines, one purpose — the Kronos platform. Hyperion — The Breeder 001 The Machine That Fathers the Sun-Fuel: Why Kronos Builds the Breeder First Every fusion economy needs a fuel supply before it needs a power plant. Hyperion is the fuel supply. 002 Small by Geometry: The Aspect-Ratio-2.5 Spherical Tokamak A fatter torus wins more plasma pressure from every tesla — that is the whole compactness case. 003 Solved, Not Scaled: Where Q = 3.424 Actually Comes From The most important thing about Hyperion's gain is how it was obtained, not how large it is. 004 The Breeder's Design Point, on One Card One operating point, every subsystem checked against the same numbers. 005 9.86 Million Amps: Current as a Buildability Choice Plasma current is the hardest engineering bill in a tokamak, and Hyperion's is set by its compact geometry. 006 Denser Than SPARC: Heating Power Density as the Real Metric How hard a fusion core works is measured per cubic metre, and Hyperion works hard. 007 No Heroics Required: Confinement at H98 = 1.0 Hyperion's gain does not depend on beating the confinement scaling law — only on meeting it. 008 Breeding Ratio Is a Lever, Not a Constant How much tritium Hyperion makes per tritium burned is a design choice, and the design chose 1.8. 009 Three Products From One Plasma: Tritium, Helium-3, Neutrons Hyperion is a foundry, not a generator — and it makes three materials the United States cannot source at scale. 010 The 14 MeV Neutron a Mirror Cannot Make Materials qualification needs fusion-spectrum neutrons, and only the D-T breeder produces them at rate. 011 Sized to the Requirement: Tritium at 1.87-4.0 kg/yr Hyperion is built to a stated national tritium need, not to whatever a physics optimum happens to yield. 012 How a Tritium Machine Makes Helium-3 The burner's scarce fuel is a free decay product of the breeder's primary output. 013 Declaring the Ash: Why f_He4 = 0.05 Is Printed, Not Buried The number under the gain is the helium ash fraction — and Kronos writes it down. 014 Capacity Factor: Damage-Life-Limited, Not Duty-Limited Hyperion runs steady-state, so its uptime is set by how long the first wall survives, not by a pulse cycle. 015 A Four-Year Build, by Precedent Hyperion's schedule is anchored to a real compact-HTS device, not to an aspiration. 016 Fuel Follows Purpose: Why the Breeder Burns D-T Hyperion and the burners run different fuels on purpose — each fuel chosen for what the machine must do. 017 Inside Existing Practice: Hyperion's Tritium Inventory The breeder's radiological posture is bounded by design to stay inside civil licensing practice. 018 Gain Only: The Milestone Hyperion Does Not Need to Clear The breeder is buildable because it is excused from the hardest bar in fusion — net electricity. 019 HTS Magnets for a Compact Core High-temperature superconducting tape is what lets a 1.2-metre machine reach reactor conditions. 020 Designing to a Requirement, Not an Optimum The most consequential choice in Hyperion is a philosophy: build what is needed, not what is maximal. The Burner — Aegis & MetroVolt 021 One Generator, Two Housings: Aegis and MetroVolt Aegis and MetroVolt are the same D-3He mirror in two markets — not two machines. 022 Open Field Lines: Why the Burner Is a Mirror The burner's signature move is to let the plasma leak — on purpose, into a converter. 023 The Locked Mode M Closing Point: Q_E 1.31, On One Hard Requirement The burner has a reproducible closing point — contingent on an end-plug density that is specified, not yet demonstrated. 024 The One Number That Decides Closure: Plug Density Ratio Not field, not size, not fuel mix — the burner's fate rests on the end-plug density ratio. 025 Length Sets Size, Not Closure The mirror's central-cell length is a free knob — it changes power and footprint, not whether the machine works. 026 Aegis: The Defense Housing of the Burner Aegis is the defense configuration — resilient, fuel-logistics-free power for fixed installations. 027 MetroVolt: The Data-Center Housing of the Burner MetroVolt is the commercial configuration — firm, carbon-free campus power with no steam cycle and no long-lived waste. 028 Fixed Site, Not Shipboard: A Computed Negative Kept in the Open The naval-propulsion version of Aegis does not fit in a hull — and Kronos published the reason. 029 A Generator on 1.66 Acres The burner's folded footprint is small enough to site where power is actually needed. 030 17 Tesla, Already Built: The Mirror Throat Field The burner's high-field magnets sit on a demonstrated number, not an extrapolated one. 031 Beta 0.55, Inside What GDT Measured The burner runs at a plasma pressure fraction experiments have already reached. 032 The Mirror-Ratio Penalty, Settled: 1.21x, Not 3.3x A worry that the burner's confinement carried a hidden penalty turned out to be overstated by design. 033 How a Mirror Holds Plasma: Pastukhov and the Confining Potential The burner's confinement is electrostatic — a potential hill the plasma must climb to escape. 034 Solved, Not Assumed: The Electron Temperature The burner's electron temperature is an output of the power balance, and it is not equal to the ion temperature. 035 The Charged-Power Budget: Why Open Systems Are Different A mirror must pay its end losses out of charged power — and that single fact governs the burner. 036 Why Pure Deuterium Does Not Close in a Mirror Deuterium-only fuel has better mirror confinement than D-3He — and still cannot close. Here is why. 037 The Closure Window: Helium-3 Fraction 0.20 to 0.43 There is a fuel-mix window in which the burner closes — bounded on both sides, and published. 038 The Fuel Mix Is a Neutron Knob — and the Machine Gets Cleaner With Time Raising the helium-3 fraction cuts neutron output ~4x across the closure window — and one step is free in gain. 039 An Interior Optimum: Ion Temperature at 80-100 keV The burner's ion temperature has a real peak, not a monotone trend — and the design sits on it. 040 Wide in Nine of Ten Parameters — and That Is the Problem The burner is not a knife-edge. Its trouble is the opposite: most knobs barely matter. 041 Unchannelled on Purpose: No Speculative Physics in the Baseline The burner's baseline assumes zero alpha channelling — because no one has ever measured it. 042 A Reproducible Closing Point, and the One Requirement It Rests On The burner has a locked, reproducible closing point (Q_E 1.31) — honest that its closure is a requirement, not yet demonstrated. Low-Neutron by Design 043 Low-Neutron, Never Aneutronic: A Few Percent Is Small and It Is Not Zero The burner's fuel is quiet, not silent — and the language stays honest about the difference. 044 The Neutron Fraction Is Not a Fuel Constant How neutronic the burner is depends on how well it confines — a coupling most models miss entirely. 045 The Coupling Nobody Models: Better Confinement, More Neutrons Improving the plasma's confinement raises its neutron output — a trade the design has to hold in view. 046 The Gentle Wall: Far Below the Breeder's Neutron Load A low-neutron fuel gives the burner a first wall that is comfortable, not consumable. 047 D-3He Versus D-T: The Neutron Budget Compared Choosing the fuel is choosing the plant you must build around it — and the neutron budget is the fork. 048 Tuning the Neutron Output From the Fuel Line The burner's neutron production is set decades in advance, at the fuel mix — and it is adjustable. 049 The Secondary Burn: Where the Burner's Neutrons Come From The burner breeds a little tritium and burns 17% of it — and that secondary D-T is a real neutron source. 050 No Breeding Blanket: The Component the Burner Deletes Because the burner does not run on tritium, it needs no blanket to breed it — and that removes a whole plant. 051 Quiet Structures: Activation and the Low-Level-Waste Path Fewer neutrons means less activated steel — and a decommissioning stream that fits existing disposal. 052 Designed to Die of Old Age: Materials Dose Over Plant Life The burner's wall is engineered to reach the end of the plant's life, not to be swapped on a cycle. 053 Two Neutrons, Two Purposes: 2.45 MeV Versus 14 MeV The burner's neutrons are the wrong energy for materials testing — on purpose. That job belongs to the breeder. 054 The Breeder Is Neutron-Rich on Purpose One machine in the family wants neutrons — and designs to make them at full rate. 055 Tritium-Lean by Design: A Trace Species in the Burner The isotope that dominates fusion licensing is only a fleeting trace in the burner. 056 Shielding a Quiet Machine Fewer neutrons means thinner shields, lighter structures, and more of the machine doing useful work. 057 The Maintenance Dividend of Low Neutrons The quiet fuel's biggest payoff is not physics — it is the outages that never have to happen. 058 Neutron Provenance: Every Channel Computed From Cross Sections The burner's neutron budget is not a literal in a file — it is derived, channel by channel. Direct Energy Conversion & Power Handling 059 Electricity Without the Steam Detour When fusion energy arrives as charged particles, you can collect it like electricity — because it already is. 060 The Expander: Turning a Beam Into a Collectible Sheet Before the burner can convert its exhaust, it has to spread it out — that is what the expander does. 061 The Number That Feeds the Converter: Directed Fraction 0.648 How much of the burner's power arrives as collectible directed energy is a computed value — with synchrotron charged. 062 0.871 Is a Ceiling, Not a Design Value A flattering directed-fraction number exists in the record — and the design refuses to use it. 063 Handling the Heat: 3.7 MW/m2 on the End Wall The burner's exhaust has to land somewhere — and where it lands is engineered to survive it. 064 Electron Direct Conversion: A Named Gate, Not an Assumption One of the two things standing between the burner and net electricity is a converter that must be demonstrated. 065 The Dominant Loss: Synchrotron Radiation at Half the Fusion Power The single largest energy loss in the burner is not the end leak — it is the light the electrons emit. 066 Bracketing the Uncertainty: Trubnikov, AFJ, and the Optically-Thin Bound The burner does not trust one synchrotron formula — it publishes the whole bracket, including the one that fails. 067 Survival by Reabsorption: The Burner's Most Consequential Assumption The design closes only because the plasma reabsorbs most of its own synchrotron light — and that fraction is unmeasured. 068 Bremsstrahlung, Cross-Checked The burner's second radiation channel is computed two ways, and the design uses the more cautious one. 069 Recirculating Power: What the Plug Costs the Plant The burner spends a large fraction of its own output keeping the plug alive — and that spend is the ledger's crux. 070 Converter Efficiency in the Window The direct converter's efficiency matters — but not as much as the one parameter that actually decides closure. 071 Diversified Power Handling: Directed, Radiated, and Residual The burner does not rely on a single conversion path — it collects power in several complementary ways. 072 Honest Lower Bounds: The Energy Convention the Ledger Uses Where the physics was ambiguous, the burner chose the convention that understates its own output. Method, Safety & Trust 085 The Fusion Company That Shows Its Work Kronos's differentiator is not a claim about performance — it is a commitment to candor. 086 Frozen Points and Recorded Withdrawals A frozen number at Kronos is a commitment against silent change — not a claim of final truth. 087 Reproduced From Source: Eleven of Eleven Checks Before a number is frozen, it is re-derived from its origin — and the re-derivation is logged. 088 Bit-Exact: Verifying Against the Prior Evaluator When the burner's new solver replaced the old one, it first reproduced the old one exactly — then corrected it. 089 Declared Basis Over Silent Basis The recurring lesson in the Kronos record is not about arithmetic — it is about stating your assumptions. 090 Named Gates, Not Hidden Assumptions Every Kronos machine states the specific things that must be demonstrated before it works. 091 Labeled History: Superseded Values Are Kept, Not Deleted When a Kronos number changes, the old one stays in the record with an era label — on purpose. 092 Deterministic by Construction: No Randomness in the Answer The burner's design point is a solve on a fixed grid — run it again and you get the same number. 093 Naming the Largest Open Item The burner's design record points directly at its own biggest weakness — and calls it the next track's job. 094 Cross-Checks From Independent Physics The burner's headline gain is trusted because a different method reached nearly the same number. 095 Read the Limitations First The burner's design record asks you to read its caveats before quoting anything above them. 096 Safety Posture: A Trace Source Term and No Repository The burner's low-neutron fuel makes its safety case categorically different from a D-T plant's. 097 Licensing Posture of a Low-Neutron Plant The burner's biggest schedule advantage may be regulatory, and it comes straight from the fuel choice. 098 An Experiment, Not a Power Plant: The Founder's Baseline The phrase that governs every Kronos claim is a refusal to call an experiment a power plant. 099 Sensitivity Published, Not Buried Kronos ranks its parameters by how much they matter — and publishes the ranking, inconvenient entries included. 100 Open Deposit: Data and Code, Not Just Claims Every headline number in the Kronos record traces to deposited data and runnable code.