What is HYPERION?
HYPERION is the Kronos breeder — a compact spherical tokamak that burns D–T to reach gain and to breed the fuel the burner needs. It is step one of a two-machine plan.
- Type
- Spherical tokamak · D–T
- Gain (Q)
- 3.424 — solved from the power balance
- Fusion power
- 88.7 MW · plasma current 9.86 MA
- Size
- R₀ 1.2 m · aspect ratio 2.5
- Breeding
- TBR up to 1.8 → ≈ 4.0 kg/yr tritium
- Availability
- Steady-state, damage-life-limited CF 0.58–0.83 (central 0.69)
HYPERION is deliberately small and deliberately hot. At an aspect ratio of 2.5 and a major radius of just 1.2 m, it reaches an engineering gain of Q 3.424 — a figure solved from its own power balance, not scaled from a larger machine. Its heating power density (2.37 MW/m³) is about 2.2× that of SPARC, a physicality test the design is meant to pass, not dodge.
Its job is twofold. First, gain: demonstrate a compact tokamak that produces far more fusion power than it takes to sustain. Second, breeding: with a tritium breeding ratio treated as a design lever (1.1 / 1.5 / 1.8 in the scan), the design point breeds about 4 kg of tritium per year — the seed stock for the breeder-first strategy.
Because it runs steady-state rather than pulsed, HYPERION's availability is limited by component damage life rather than duty cycle — a capacity factor in the 0.58–0.83 range, central estimate 0.69. That is a more honest basis than an idealized pulse fraction, and it is the number the economics are built on.