The breeder — Hyperion

Hyperion is a spherical tokamak designed as a materials platform. It breeds tritium — the fuel fusion needs and the world is short of — and produces isotopes. Its defining gate is tritium self-sufficiency, not net electricity.

A low aspect ratio gives a compact, high-β configuration — more plasma pressure for the magnetic field. Paired with negative triangularity, it's a shape that holds heat well in a small machine. See the equilibrium.

It's a plasma cross-section whose corner points outward (δ = −0.30), the opposite of a conventional tokamak. Nonlinear gyrokinetics (CGYRO) shows this shape suppresses the turbulence that otherwise drives heat out — the single most consequential physics choice in the design.

Most tokamaks use a central solenoid to drive current. Hyperion doesn't need one: a large bootstrap current from the plasma's own pressure gradient, topped up by RF current drive, sustains 9.66 MA non-inductively. Freeing the central column is what makes the compact spherical geometry possible. See current drive.

The ratio of tritium the machine produces to the tritium it consumes. Above one means self-sufficient. Hyperion reaches up to 1.42 on-model, computed with OpenMC neutronics, with margin for the fuel cycle's losses (tracked with TMAP8).

No — and it makes no such claim. It is a platform whose success is measured in tritium and isotopes. That honest gate is stated on every page; net electricity is the burner's and the fleet's later game, not the breeder's promise.

Q 3.076 at 85.04 MW fusion power, 9.66 MA plasma current (solenoid-free), δ −0.30, α-confinement 99.98%, TBR up to 1.42 — canon-locked to the 2026-08-27 freeze. Explore them in the operating-point explorer.

Every number traces to a gate in the De-Risking Register and a code deep-dive under The Codes. The V&V matrix shows how each is qualified.