Fusion Core Assembly Enters Bold New Phase

The world’s largest fusion project, ITER, has launched the final assembly of its reactor core, marking a giant step toward harnessing clean, limitless energy.

“This is the most complex machine ever built, and it shows what the world can achieve when nations work together,” said ITER Director-General Pietro Barabaschi.

At the heart of the project is the tokamak’s vacuum vessel, made up of nine massive steel sectors, each weighing around 400 tons, which must be fitted with millimetre precision. Once complete, the reactor aims to produce 500 megawatts of power from just 50 megawatts of input — a tenfold energy gain that would prove fusion’s viability as a global energy source. With 35 countries collaborating on the project, this milestone demonstrates that international cooperation can turn the dream of star power into a tangible path toward a clean energy future.