Uploaded December 2025 | Updated September 2026, 2 weeks ago
Fusion used to follow one rule: build it bigger. Bigger tokamaks meant more plasma volume, longer confinement, and a better shot at break-even. That’s why the world built ITER, a monster project costing tens of billions. But MIT and Commonwealth Fusion Systems are betting on a different lever: insanely strong magnets. New high-temperature superconductors like REBCO can push past 20 Tesla, letting a reactor shrink without changing the core physics. In this video, we explain why size mattered, what the 20T test proved, and how SPARC plans to chase net energy—fast.
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SPARC or ITER—who hits net fusion first?
Fusion used to follow one rule: build it bigger. Bigger tokamaks meant more plasma volume, longer confinement, and a better shot at break-even. That’s why the world built ITER, a monster project costing tens of billions. But MIT and Commonwealth Fusion Systems are betting on a different lever: insanely strong magnets. New high-temperature superconductors like REBCO can push past 20 Tesla, letting a reactor shrink without changing the core physics. In this video, we explain why size mattered, what the 20T test proved, and how SPARC plans to chase net energy—fast.
Pinned comment
SPARC or ITER—who hits net fusion first?
