Benchmarking Against Tokamak Databases

The breeder design point is checked against established empirical tokamak scalings and databases, so its numbers sit inside a body of measured experience rather than standing alone.

Anchoring a design in measured data

A fusion model can be internally consistent and still disagree with reality. The guard against that is benchmarking: comparing the breeder (Hyperion) design point to empirical scalings derived from decades of tokamak operation. Where the design lands inside the validated range, confidence rises; where it lands at or beyond an edge, the record says so.

The benchmark families

The design is compared against the ITER-basis energy-confinement scaling, the Troyon normalized-beta limit, the Greenwald density limit, neoclassical bootstrap-current estimates, and the spherical-tokamak-specific record from machines in the NSTX and MAST class. Each comparison is one or more of the 81 analyses, with the reference law and its stated range of validity cited.

Honest use of extrapolation

A compact spherical tokamak at aspect ratio 2.5 and R0 1.2 m sits at the edge of where some conventional scalings were fitted. The record does not pretend a scaling law validated at conventional aspect ratio transfers unchanged to low aspect ratio; it flags such extrapolations as assumptions to be tested at FOAK.

Benchmarking is a triangulation, not a single verdict. Confinement, beta, density, and bootstrap current each constrain the design from a different direction, and a point that sits comfortably inside all of them at once is far better supported than one that clears each limit in isolation. The value of the exercise is in the joint picture, which is why the benchmark analyses are read together rather than one at a time.

This page describes a design-and-simulation study, not a built machine. Construction of the breeder (Hyperion) begins Q2 2027; first-of-a-kind first tritium is targeted near 2030. No hardware net-gain claim is made before FOAK.