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Question
What fuels does fusion use?
Most fusion uses deuterium–tritium. Kronos uses low-neutron deuterium–helium-3, with deuterium from seawater and helium-3 bred in the plant itself.
Fuel choice is one of the defining decisions in fusion, because it sets how many neutrons the plant produces and how the energy can be captured. Kronos chose D–³He over the more common D–T precisely to be low-neutron and directly convertible.
See the main fusion reactions for how the options compare.
Questions & answers
What fuels can fusion use?
The practical fusion fuels are combinations of hydrogen isotopes and light elements: deuterium–tritium (D–T, easiest), deuterium–deuterium (D–D), deuterium–helium-3 (D–³He, low-neutron), and proton–boron-11 (p–¹¹B, aneutronic but hardest). They trade ease of ignition against neutron output.
What does Kronos use?
Kronos runs a staged, catalyzed deuterium–helium-3 (D–³He) cycle. It is low-neutron and produces mostly charged particles, which its direct-energy converter can capture.
Where does the fuel come from?
Deuterium is extracted from ordinary seawater and is effectively unlimited. Helium-3 is scarce on Earth, so Kronos breeds its own in the plasma via the catalyzed D–D branch rather than buying it.