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Question
How hot is a fusion plasma?
A fusion plasma runs at over 100 million degrees — hotter than the sun's core. Kronos targets central ion temperatures around 65–70 keV, roughly 750 million °C.
Fusion temperatures are staggering — hundreds of millions of degrees — but they are held in a magnetic field, never in contact with matter. Kronos runs the ions hotter than the electrons (65–70 keV vs 34 keV), a deliberate hot-ion posture that maximizes fusion while limiting radiation.
Questions & answers
How hot does a fusion plasma get?
Well over 100 million degrees Celsius — hotter than the core of the sun. Fusion physicists usually quote temperature in kiloelectronvolts (keV), where 1 keV is about 11.6 million degrees. Kronos MetroVolt targets central ion temperatures of 65–70 keV, roughly 750 million °C.
How can any material survive that?
Nothing touches the plasma. It is held in a magnetic bottle — magnetic confinement — so the hundred-million-degree plasma never contacts the wall. The wall handles heat and particle flux at its edge, but not the core temperature.
Why so hot?
Because nuclei repel each other electrically, they must move fast enough — hot enough — to overcome that repulsion and fuse. Deuterium–helium-3, the Kronos fuel, needs even higher temperatures than deuterium–tritium, which is part of why the design runs a hot-ion posture.