Here’s what you’ll learn when you read this story:The plasma density barrier is a mathematical limit to the density of plasma that can exist in a tokamak before destabilizing. One of those limitations is what’s known as the plasma density barrier, or the Greenwald limit (named after American physicist Martin Greenwald who discovered the limit in 1988). Because plasma-wall interactions were organized from the beginning, the tokamak successfully achieved plasma densities 65 percent beyond the Greenwald limit. Related Story Negative Triangularity Fusion Reactor Goes OnlineWhile the fusion world eagerly awaits the construction of the International Thermonuclear Experimental Reactor (ITER) in southern France, the EAST reactor in China is one of the leading tokamak reactors in the world. Of course, reliably surpassing the Greenwald limit won’t magically open the doors to a world powered by fusion.