Magnetic confinement fusion
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Once again, relies on superconductivity to reach insane magnetic fields. Superconductivity is just so important.
Ciro Santilli saw a good presentation about it once circa 2020, it seems that the main difficulty of the time was turbulence messing things up. They have some nice simulations with cross section pictures e.g. at: www.eurekalert.org/news-releases/937941.