Magnetic coil, maker: AGAN Consortium (ACCEL Instruments, Alstom, Ansaldo, Babcock Noell Nuclear, Europa Metalli), 2000, ca. 4.1 × 2.3 × 6.7 m. KIT North Campus, corner of Eggensteiner Strasse/Blankenlocher Strasse.
The fusion of hydrogen nuclei releases a significant amount of energy. The experimental reactor ITER (International Thermonuclear Experimental Reactor), currently under construction in France through international collaboration, aims to develop the technological foundation for a fusion power plant by 2035. A central component of ITER’s design are the kidney-shaped electromagnetic coils, each approximately 7 meters in height, as illustrated here. These coils are arranged in a ring inside the fusion reactor, enclosing the space that contains the fuel needed for fusion. Magnetic coils are essential because nuclear fusion occurs at temperatures of several hundred million degrees Celsius. This process is only manageable if the fusion fuel mixture is kept suspended without touching the reactor walls. This is achieved by generating a magnetic field of 10 Tesla — equivalent to the weight of the Eiffel Tower. Creating such a strong magnetic field requires an electrical current of 80,000 amperes, a level that would instantly destroy ordinary copper wires. This problem is overcome by constructing the magnetic coils out of superconducting niobium-tin (Nb₃Sn). When cooled below –255.15 °C, electrical resistance in this material is nearly eliminated, allowing the conductor to withstand the immense current needed to generate the magnetic field. These magnetic coils are produced industrially. To test them, the Institute of Technical Physics at Karlsruhe Research Center developed the Toroidal Coil Test Assembly Karlsruhe. This development was based on decades of research into superconducting materials at the Center. kn