The race for breakeven fusion is heating up, and it's exciting to see. That old adage about reaching breakeven being 'always 30 years in the future' is actually, finally looking more like 5-10 years. Relevant projects, all tokamaks: The largest ever fusion reactor so far which is being built now -- ITER in France, then there's MIT/Commonwealth Fusion's SPARC (they just demoed a type 2 superconductor magnet that developed 20T in its rather large borehole), China's EAST reactor and its recent 200+ million degree temperature and confinement time records, and the venerable JET reactor in the UK, which still holds the Q record of ~0.67 with D+T and they are prepping for another tritium run. These projects are some of the leaders in the field, amongst many others.

The stellarators are also fascinating projects though even more geometrically complex than tokamaks are. The Moebius strip-like twist allows them to impart stability to a ring of plasma in ways that tokamaks can't. The Wendelstein X7 in Germany and the Large Helical Device in Japan are the largest and most recent examples. The Princeton Plasma Physics Lab has a novel stellarator design called NCSX, which interestingly uses coils and arrays of permanent magnets.

The advent of type 2 superconductors at scale will contribute greatly to this speed-up to acheive breakeven with tokamaks and stellarators. The much smaller and newer design MIT SPARC (which will use the more recently developed type 2 superconductors) might even beat ITER(which uses type 1 superconductors) to Q=1+!