Deep Dive: The Gate Program

Kronos advances through pre-registered gates — G1 confinement, G2 magnet, G3 fuel loop — with a pilot plant between the testbed and the commercial unit.

G1

Confinement testbed — NT-ST, ~$0.5B, ~4 yr

G2

Magnet & peak field (≥25 T; 24.6 T envelope)

G3

Fuel loop (>95% single-pass DIR)

FPP

Pilot plant between G1 and commercial

Kronos structures development as a gate program — each gate retires a specific, load-bearing risk with a real experiment before the next commitment, and carries pre-registered predictions published regardless of outcome.

• G1 — Confinement testbed. A sub-scale negative-triangularity spherical tokamak (3 T, R₀ = 0.85 m, ~$0.5 B, ~4 years to first plasma) that measures confinement (P1), the hot-ion posture (P2), aligned high-β_p (P7), and the channeling proof-of-principle (P6). The single most consequential step — it tests the scaling; only the full plant tests the value.
• G2 — Magnet & peak field. Sustained ≥ 25 T conductor performance and the 24.6 T envelope (P3).
• G3 — Fuel loop. > 95% single-pass direct internal recovery (P4).

Between the testbed and full MetroVolt sits a fusion pilot plant (R₀ = 2.7 m, ~0.25 GW-class) that proves integrated operation.