Startup Control Raises Fusion Density Limit

EAST researchers demonstrated that deliberate control of tokamak startup—tuning fueling pressure and applying brief electron‑cyclotron heating to shape the initial plasma‑wall boundary—can cut impurity influx and push operating density roughly 65% above the conventional Greenwald limit. This indicates the 'limit' is an operational, not purely fundamental, constraint and that reactor startup protocols are a high‑leverage engineering knob. — If reproducible, recasting the Greenwald limit as avoidable by startup and boundary control accelerates fusion commercialization timelines and changes where governments and investors should target funding (control systems, materials, DEMO licensing).