Photos: World’s biggest fusion reactor adds over 1,200-ton module in major progress

On November 25, ITER made significant progress in assembling the world’s largest fusion reactor by successfully installing the third vacuum vessel sector module, known as sector module #5, into the tokamak pit. This nearly 1,213-ton component represents one of nine 40° sections that form the plasma chamber, each including a vacuum vessel sector, thermal shield, and superconducting magnets essential for plasma shaping and stabilization during fusion experiments. Notably, sector #5 was the first European-built module installed, presenting new challenges that required precise coordination and planning. A key achievement during this installation was the reduction of the offset between adjacent modules from 100 mm in a previous installation to just about 10 mm, reflecting improved precision and teamwork. The operation also tested the vacuum vessel gravity support system, successfully aligning the module’s connection point with the support structure, a critical step for future module placements. As the pit becomes more crowded with modules, maintaining tight installation margins is vital for safety and efficiency. With sector #