Power Balance in the Machine

Q_sci 3.076 means the plasma produces 85.0 MW of fusion power for the heating put into it, a gain figure, not a net-electric claim.

What Q_sci measures

Scientific gain Q_sci is the ratio of fusion power produced to the heating power delivered into the plasma. Hyperion's design point is Q_sci 3.076 at 85.0 MW of fusion power, meaning the plasma generates several times the power injected to heat it. This is the figure that matters for a foundry: it is the gain that produces the neutron flux driving breeding and irradiation.

Gain is not net electric

Q_sci counts only the heating delivered to the plasma. It does not subtract the power drawn by magnets, cryogenics, pumps, and the rest of the plant, nor does it involve converting fusion power to electricity. Net electrical output is a harder, separate threshold. Hyperion is a breeder judged on gain and neutron production, not on net electricity, which is why the foundry logic works at Q_sci 3.076 without a net-electric claim.

Why gain suffices for the breeder

The breeder's product is material, tritium, helium-3, and 14 MeV neutrons, all driven by fusion power, not by exported electricity. A Q_sci of 3.076 producing 85.0 MW delivers the neutron economy the blanket needs. Importantly, this remains a design-and-simulation target: no hardware net-gain claim is made before the first-of-a-kind machine reaches first tritium near 2030, and the machines described here are studies, not yet built.

• Q_sci 3.076 = 85.0 MW fusion per unit of plasma heating
• Gain is not net electric and makes no such claim
• The neutron flux from that gain is the breeder's product

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.