Radiated Power Fraction

The share of exhaust power radiated before it reaches the divertor targets.

Deliberately radiating a large fraction of the exhaust power spreads it over the whole wall instead of concentrating it on the divertor. HYPERION's divertor design relies on a high radiated fraction — an effective technique with a real performance gate attached.

Deliberately radiating a large share of the exhaust power is the primary tool for protecting the divertor, spreading heat over the whole wall instead of a small target. HYPERION's divertor design depends on a high radiated fraction, which Kronos flags as a performance gate because achieving it while keeping the core clean is a genuine balance.