Q_scientific vs Q_engineering

Q_sci compares fusion power to heating power; Q_eng compares net electricity to everything the plant draws. Kronos reports the breeder's Q_sci and does not conflate the two.

Two different ratios

Fusion gain has more than one meaning and the difference decides whether a claim is honest. Q_scientific is fusion power divided by the power injected to heat the plasma. Q_engineering is net electrical output divided by all electrical power the plant consumes — magnets, heating, cryogenics, and balance-of-plant. Q_eng is always the harder threshold.

What Kronos reports

The breeder (Hyperion) design point is Q_sci 3.424 in simulation. That is a scientific-gain figure, and we always label it as such. It is not a claim of net electricity. The breeder does not need net-electric gain to deliver value, because its product is isotopes and neutrons, which the fusion power itself produces.

The burner's ambition

The burner (Aegis / MetroVolt) is designed toward net-electric output using direct energy conversion of charged particles. That is an engineering-gain goal, and it remains a design goal — not a measured result, and gated on physics we describe honestly elsewhere.

Whenever we cite a Q, we say which Q, from what source. A Q_sci figure quoted as if it were Q_eng is one of the most common ways fusion numbers mislead, and we guard against it deliberately.