Energy Confinement Scaling

Confinement scalings predict how long a plasma holds its heat; extrapolating them to Hyperion's compact, high-field, negative-triangularity point is an open exercise.

Predicting confinement

Energy confinement time, tau_E, is how long the plasma retains its thermal energy against transport losses. It is the hardest quantity to predict from first principles, so the field relies on empirical scaling laws fit to databases of many experiments, expressing tau_E as a function of current, field, size, power, and density.

Hyperion's gain of Q_sci 3.076 depends directly on tau_E: longer confinement means more fusion power for the same heating. The design point assumes a confinement level, and the credibility of Q 3.076 rests on that assumption holding at the machine's actual parameters.

Why extrapolation is the risk

The standard scaling databases are dominated by conventional tokamaks with positive triangularity. Hyperion sits at low aspect ratio, high field, and negative triangularity delta -0.30 — a corner of parameter space where the standard scalings are least tested. Predicting confinement there is a design-and-simulation extrapolation, and it is exactly the uncertainty the first confinement gate is meant to retire. Rather than lean on a single scaling, the design compares first-principles turbulence modeling against the empirical fits and treats the spread between them as the honest uncertainty band on tau_E — the band that ultimately sets how confidently Q_sci 3.076 can be quoted before hardware exists.

• tau_E governs how much fusion power a given heating yields
• Empirical scalings extrapolate from mostly conventional tokamaks
• Hyperion's ST + negative-triangularity point is under-represented in that data

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