ITER (IMAGE) Lehigh University Caption The first module of ITER’s toroidal plasma chamber is placed inside the tokamak pit. Each one of the nine modules, which is composed of a 40° vacuum vessel sector covered by thermal shields and two superconducting toroidal-field coils, weighs approximately the equivalent of four fully loaded Boeing 747s and is as tall as a six-story building. The ITER tokamak, under construction in southern France, will be the largest fusion reactor in the world. Credit Eugenio Schuster/Lehigh University Usage Restrictions Credited, contextual use only License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.