The Staged Fuel Cycle

Kronos runs fusion fuels in stages — from D–T commissioning to a ³He-rich optimum toward the p–¹¹B endpoint — trading difficulty for ever-lower neutrons.

Stage 0

D–T — commissioning only

Early

D-rich D–³He (commercial baseline)

Optimum

³He-rich (DEC η ≈ 0.60)

Endpoint

p–¹¹B (gated, aneutronic)

Rather than commit to one fuel, Kronos MetroVolt runs a staged fuel cycle that moves through progressively cleaner, harder reactions as the machine and program mature. A brief D–T stage commissions the plant; D-rich D–³He is the commercial baseline; a ³He-rich mix is the conversion optimum (where DEC efficiency peaks near 0.60, per analysis S71); and the p–¹¹B endpoint is a gated research destination.

Each step trades higher physics difficulty for lower neutron output, and the plant breeds its own ³He along the way via the catalyzed D–D branch. Staging lets the company earn revenue on an achievable baseline while advancing toward the aneutronic endpoint — and it is why the neutron fraction is quoted as a range (5.25–7.05%) along the schedule rather than a single number.