Learn › Questions people ask
Question
How strong is a 24-tesla magnet?
Very strong — roughly ten times a hospital MRI and about half a million times Earth's magnetic field. That field strength is what lets a compact tokamak work.
24.6 tesla is an extraordinary field, and it's the reason a 5.75 m machine can target gigawatt-class power. See the 24.6 tesla magnet system and fusion power density.
Questions & answers
How strong is 24 tesla, really?
For scale: Earth's magnetic field is about 0.00005 tesla, a fridge magnet a few hundredths, and a hospital MRI machine 1.5–3 tesla. Kronos's 24.6-tesla peak field is roughly ten times an MRI and about half a million times Earth's field — among the strongest continuous fields built for any purpose.
Why does the design need it that high?
Fusion power density scales with the fourth power of magnetic field, so a higher field means a far more compact, economical machine. Field is the strongest single lever a fusion designer has.
Is that field level achievable?
It sits just above the demonstrated 24.4-tesla single-coil field (Tokamak Energy, 2025), so Kronos treats it as a stated technology gap — defended by a strain clamp and qualified at the G2 gate, not assumed.