https://www.thehindu.com/sci-tech/science/china-east-fusion-reactor-beats-greenwald-plasma-limit-widens-path-to-power/article70500702.ece
For decades, tokamaks have hit a ceiling called the Greenwald limit. Pack in more fuel than that and the plasma tends to collapse. China’s EAST reactor in Hefei usually runs at 80–100% of it. In a January 1, 2026 paper in Science Advances, the team reported stable plasmas at 1.3 to 1.65 times the limit.
The trick: microwave (ECRH) heating during start-up, plus more deuterium gas at the start. That kept the divertor cooler and knocked less tungsten off the walls, so the plasma stayed cleaner. The results fit plasma-wall self-organisation theory, which predicts a “density-free” regime.
It doesn’t solve fusion. The shots were low-power and lasted seconds. But denser fuel could lower the bar for ignition, which matters for ITER.
Source: www.thehindu.com · Also: Science Advances paper (PMC)