Fusion technology offers a promising solution to the world’s increasing demand for carbon-free energy, and ITER, the world’s largest fusion experiment, is taking a major step towards operational status with the delivery of all the special magnets needed to build its reactor core in southern France. The design process for ITER has spanned over two decades and involved manufacturing components across three continents.
ITER’s unique tokamak reactor uses hydrogen to create plasma in a doughnut-shaped vacuum chamber, simulating the conditions at the core of the Sun. The plasma is heated to an extreme temperature of 150 million degrees Celsius to initiate fusion reactions. To confine the plasma within the reactor and control its behavior, giant superconducting magnets are used. These magnets utilize niobium-tin and niobium-titanium as fuel, with an intricate cooling process to facilitate superconductivity.
The design of ITER includes various types of superconducting magnets strategically placed to form an invisible magnetic cage that contains the plasma. D-shaped magnets, horizontal surrounding magnets, and a central solenoid all work together to create and control the plasma currents within the tokamak. The magnetic fields produced by these magnets are incredibly strong, with a total energy of 41 gigajoules – vastly surpassing Earth’s magnetic field strength.
The manufacturing process for these magnets involves winding niobium-tin filaments with copper wires, encasing them in steel housings, cooling them to superconducting temperatures, and assembling them into intricate structures. Once operational, ITER is expected to produce 500 MW of power – with 200 MW of continuous electricity feed into the grid – providing energy for approximately 200,000 homes.
