Confinement Scaling Laws

Empirical formulas (like IPB98) that predict energy confinement time from machine parameters.

Assumption

H98 = 1.0

Confinement time

0.374 s

Because turbulent transport resists first-principles prediction, the field uses empirical scaling laws — most famously the ITER IPB98 scaling — fit to a large multi-machine database, to predict energy confinement time. The multiplier H₉₈ expresses performance relative to that baseline.

HYPERION assumes H₉₈ = 1.0 — standard scaling, not an optimistic multiple — giving τ_E = 0.374 s.

Scaling laws like IPB98 are how the field turns decades of multi-machine data into a usable prediction of confinement time. Kronos designs to H₉₈ = 1.0 — standard scaling, not a hopeful multiple of it — so its 0.374 s confinement target rests on demonstrated behaviour rather than extrapolation.