The Physics of Hyperion

Hyperion is a compact D-T spherical tokamak studied to fusion gain Q_sci 3.076 at 85.0 MW fusion power, sized as an isotope foundry.

What the physics has to deliver

Hyperion is a compact deuterium-tritium spherical tokamak. Its purpose is not net electricity but neutron flux: the 14 MeV neutrons that breed tritium, transmute lithium, activate materials, and produce a helium-3 coproduct through tritium decay. The physics target is therefore fusion gain, the ratio of fusion power to the external power heating the plasma.

The frozen design point is Q_sci 3.076 with 85.0 MW of fusion power, plasma current 9.66 MA, peak field 16.84 T (8 T on-axis), aspect ratio A 2.5, major radius R0 1.2 m, and negative triangularity delta -0.30. These are the numbers every page in this section refers back to; none of them are invented here.

Why gain, not net-electric

Net-electric output requires that recirculating power for magnets, heating, cryogenics, and plant balance stay below gross electrical output. Scientific gain is a lower bar and is sufficient for a foundry, because the product is the neutron economy. That framing is what makes a compact machine at Q 3.076 useful rather than a placeholder for a later, larger device.

Honest scope

• Q_sci 3.076 is scientific gain, distinct from engineering or net-electric gain
• The tritium breeding ratio is treated as a design lever (1.1 / 1.5 / 1.8), not a settled value
• Net-versus-local breeding at target TBR 1.8 is an open reconciliation
• The center post has a limited lifetime (~0.01 fpy note)

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.