Physics · section 02

The governing physics.

What the machines are, physically — and the reduced-order balance that every headline number comes from. The live instruments (breeder engine, burner closure, reactivity) run under Physics → Breeder, Burner and Reactivity; this page is the written record behind them.

Live instrument The breeding-blanket neutronics now runs in your browser — solve the blanket → (net TBR live) · solve the divertor → · core turbulence → · magnet stress →. OpenMC / SOLPS / CGYRO / ANSYS retire the surrogates.
Governing Physics · Breeder

Governing Physics

The physics that fixes the Hyperion design point, computed live from dt_scan config 22021. Every equation opens to its substituted derivation.

Analysis
Ignition Analysis
Q 3.42
SUB-IGNITION · driven
nTτ 2.29×10²¹ < 3×10²¹ — a breeder is driven, not ignited.
Stress & Thermal
1.97 MW/m²
wall & coil OK
B_peak 16.84 T ≤ 20.1 T; 19.7 dpa/fpy → ~2.5 fpy life.
Risk & UQ
H₉₈ = 1.0
assumptions declared
δ-sign open (~2.1% on I_p); damage-life-limited CF; ash f_He4 0.05 conservative.
Blanket & Tritium
TBR 1.03–1.20
TBR 1.8 target
demonstrated Be blanket 1.34 → ~1.7 kg/yr; ~2× world T flow.
Equation catalog · click any equation for its derivation
Plasma & Confinement
Triple product (Lawson)
nTτ_E = n̄ · T_i0 · τ_E
2.29×10²¹ keV·s/m³›
Energy confinement — IPB98(y,2)
τ_E = 0.0562·H·I_p^0.93·B^0.15·n^0.41·R^1.97·κ^0.78·P^-0.69
0.374 s›
Bootstrap fraction (Sauter)
f_bs = I_boot / I_p
0.155›
Normalized beta
β_N = β_t · a·B₀ / I_p
1.532 / 4.2›
Fusion & Power
Fusion power (D–T)
P_fus = n_D·n_T·⟨σv⟩·E_DT·V_p
85.0 MW›
Neutron / charged split
P_n = f_n · P_fus
70.7 MW›
Fusion gain — SOLVED
Q = P_fus / P_aux
3.076›
Bremsstrahlung radiation
P_br = C·Z_eff·n_e²·√T_e·V
3.25 MW›
Neutron first-wall load
q_n = P_n / A_wall
1.97 MW/m²›
Fuel Cycle
Net tritium production
T = f(TBR, P_n)
4.0 kg/yr›
Startup inventory
from breed-up dynamics
6.47 kg›
Breeder deposit · DOI 10.5281/zenodo.21746157 · reproduced from the open Zenodo/GitHub deposit (CC BY 4.0). Canonical freeze: FROZEN_2026-08_PUBLICATION.csv.
🔒 Governing Physics is Kronos-only. The overview above is public — the full data, tables, live calculations and engineering detail on this page require a Kronos team sign-in.
Core Systems · Breeder

HYPERION — the tritium & neutron engine

A compact spherical-tokamak (A 2.5, R₀ 1.2 m) run as a deuterium–tritium breeder: its product is the tritium, neutrons, and helium-3 that fuel everything else — not net grid electricity. Every figure below reproduces the frozen design point bit-for-bit.

β_N
1.53 / 4.2
no-wall NSTX limit
q₉₅
3.0
H₉₈
1.00
f_bs
0.15 boot
Z_eff
1.16

Design Targets → Consistency config 22021

ParameterValueBasisStatus
Fusion gain Q3.076SOLVED — P_fus/P_auxPASS
Fusion power P_fus85.0 MWCOMPUTEDPASS
Neutron power P_n70.7 MWf_n 0.797PASS
Plasma current I_p9.66 MA1.50 boot + 8.16 drivenPASS
Toroidal field B₀8.0 TSCAN leverGATE
Peak coil field B_peak16.84 T≤ 20.1 T [HAR23]PASS
Neutron wall load1.97 MW/m²19.7 dpa/fpyGATE
Tritium outputTBR 1.03–1.20 (lever)TBR 1.8 targetGATE
On-duty gate1.87 ≤ T ≤ 4.0damage-life limitedPASS
Closes (no-wall)TRUEβ_N<4.2 ∧ coil OKPASS

Validated Suite reproduced

23 checks
V01–V23 · all PASS
Frozen point reproduces to 0.0e+00 rel. diff (bitwise, NumPy 2.x).
Gain is SOLVED from power balance — not the withdrawn scaled 1.889.
Deposit · DOI 10.5281/zenodo.21746157

Subsystem Status

PLASMA EQ
A 2.5 · κ 2.0
MAGNETS
REBCO · 16.84 T pk
CRYOGENICS
HTS bus stable
BLANKET / TBR
1.34 → 1.8
FUEL CYCLE
T 4.0 · ³He 1.97 kg/yr
FIRST WALL
2.5 fpy life
Breeder deposit · DOI 10.5281/zenodo.21746157 · reproduced from the open Zenodo/GitHub deposit (CC BY 4.0). Canonical freeze: FROZEN_2026-08_PUBLICATION.csv.
Physics Engine · Breeder

0-D power balance — solved live

The top readout is a fast 0-D estimate as you move the levers. For the real thing, use the Live Solver below — it runs the deposit’s actual dt_evaluator.py in your browser (Pyodide + NumPy) and reproduces the frozen point exactly.

Live Plasma Readout D–T · steady-state

Fusion gain Q
3.076
frozen anchor
Fusion power
85.0 MW
P_n 70.7 MW · f_n 0.797
Plasma current
9.66 MA
1.50 boot + 8.16 driven
Tritium output
4.00 kg/yr
at TBR 1.80
Neutron wall
1.97 MW/m²
14 MeV first wall

Real-Time Design Levers

Blanket TBR1.80
Toroidal field B₀8.0 T
Ion temperature T_i015.0 keV
Confinement H₉₈1.00
Frozen anchor: Q 3.076 · P_fus 85.0 MW · I_p 9.66 MA · TBR lever 1.03–1.20 (TBR 1.8). Tritium tracks the TBR lever (demonstrated Be blanket TBR 1.34 → ~1.7 kg/yr).

Governing Physics live-computed

Power-balance gain
Q = P_fus / P_aux
= 85.04 / 25.89 = 3.076 (frozen)
Confinement — IPB98(y,2)
τ_E = 0.0562·H·I_p^0.93·B_T^0.15·n^0.41·R^1.97·κ^0.78·P^-0.69
τ_E = 0.374 s at H₉₈ 1.0
Bootstrap (Sauter)
f_bs = I_boot / I_p
= 1.50 / 9.66 = 0.155
Tritium duty
1.87 ≤ T[kg/yr] ≤ 4.0
TBR 1.8 → 4.0 · demonstrated 1.34 → ~1.7

Live solver — the real deposit code, in your browser Pyodide + NumPy

This runs the deposit’s actual pure-NumPy evaluator (dt_evaluator.py) in your browser via Pyodide — not a re-implementation. It reproduces the frozen design point exactly; change the levers above and re-run to recompute live.

Breeder deposit · DOI 10.5281/zenodo.21746157 · reproduced from the open Zenodo/GitHub deposit (CC BY 4.0). Canonical freeze: FROZEN_2026-08_PUBLICATION.csv.
🔒 0-D power balance — solved live is Kronos-only. The overview above is public — the full data, tables, live calculations and engineering detail on this page require a Kronos team sign-in.
Live version This balance runs live on the deposited engine — drive it yourself on the Breeder instrument.
Design-Space Explorer · breeder

Design Space

Every one of the 25,200 scanned breeder configurations, plotted live. Of these only 491 close the on-duty no-wall gate — and config 22021 is the frozen Hyperion design point. Pick axes, colour, and fuel; click a point for its numbers.

5,037 configs shown
Live from data/dt_scan.csv (25,200 configs) · reproduced from the open deposit DOI 10.5281/zenodo.21746157.
🔒 Design Space is Kronos-only. The overview above is public — the full data, tables, live calculations and engineering detail on this page require a Kronos team sign-in.
Live version The interactive version of this panel runs in the team Lab — the static record is shown here.
How to read this model

Methodology & limitations

What the numbers are, how they were produced, what is validated, and — plainly — what is not yet known. This model earns trust by being explicit about its own maturity.

This is the public model — a lightweight version built to run in your browser.
Everything here is what Kronos publishes openly. Internally, the company runs the same physics at far higher fidelity on dedicated HPC — full FEA, CFD and neutron-transport (MCNP) campaigns, large parameter studies, and the workflows declared on the Compute · HPC/Q ports ↗ page. Those production runs are not shipped in this environment: this page ships the reduced-order (0-D) evaluator and the frozen results so anyone can reproduce the headline numbers. Nothing here exposes proprietary high-fidelity models, tooling, or economics.
How the numbers are produced

Every individual method — with its inputs, outputs, numerical basis and fidelity — is catalogued in the open Algorithm Library ↗.

0-D systems model
A validated zero-dimensional power-balance model sets the design point — the same evaluator you can re-run live on the Physics page.
25,201-point design scan
The design space is swept across thousands of configurations; the frozen point is chosen from that scan (Design Space page).
Monte-Carlo uncertainty
2,000-sample propagation over the real evaluator produces the uncertainty bands on the UQ page.
Screening multiphysics
Structural / thermal / EM / neutronics are screening-level today; full FEA / CFD / MCNP are declared HPC ports, not yet run.
Maturity — read every surface with its tag
Each page carries a maturity tag: MODEL (a specification), COMPUTES NOW (a real calculation you can re-run), AWAITS HARDWARE (a structure waiting for a real machine), LIVE DATA (a live external connection). The full maturity assessment is the TRL/MRL readiness view ↗.
Known limitations & open questions
Nothing is built
This is a design model — no machine, no operating data. Every performance number is a projection.
Confinement assumption (breeder)
Hyperion leans on the H₉₈ confinement factor — the largest single uncertainty; conservative and optimistic bands are shown on UQ.
Plug density (burner)
The burner net-power result requires a plug-density condition that is an open engineering requirement, flagged wherever the net numbers appear.
Screening-level analysis
Multiphysics is screening-level; high-fidelity FEA / CFD / MCNP and a licensed safety case are future work.
Not peer-reviewed yet
The deposits are open and reproducible but not journal-refereed — treat them as preprints.
Economics is gated
Cost and financing lines are proprietary and team-only; public figures are physics, not financial guidance.
This is an engineering model, not a licensed safety case or a peer-reviewed result. The open deposits are citable but not yet journal-refereed. Treat every figure as an estimate under stated assumptions.
KRONOS FUSION ENERGY · Kronos Model Conceptual design and simulation study; no machine has been built