General Atomics (San Diego, Calif.), which undertakes large-scale nuclear technology projects, has created a giant magnet for the largest fusion reactor in history, ITER, which will commence operations in 2023 in the south of France.
The dimensions of the central solenoid magnet stir the imagination: its height is 17.9 m, width 42 m and weight about 1000 tons. It took General Atomics (GA) specialists more than 5 years to create it. However, this is only half of it. Transporting it to its destination will also be a momentous task.
A marvel of engineering
According to GA Design Director John Smith, the magnet’s power will be enough to lift an aircraft carrier weighing 101,250 tons to a height of nearly two meters.
The central solenoid will consist of six modules weighing 112.5 tons each. Scientists are going to use it to create a powerful magnetic field of 15 million amperes, which will hold the plasma heated to millions of degrees inside the fusion reactor.
The first crucial component needed to transport it is a unique crane. The crane body is placed on a nine-axle truck. The other parts and components of the crane will be in 40-60 semi-trailers. The module will be shipped by rail to Houston, Florida, and from there by sea to France.
How the magnet is made
Its main components are niobium and tin. Cables are shipped from Japan to GA, where they are carefully coiled and heat-treated for five weeks at 650 °C. The result is the Nb3Sn alloy, which is a superconductor.
After the heating, the temperature is maintained for some time, after which the gradual cooling begins. A special machine covers the cooled coils with insulation. The total length of the cable is 5.6 km.
The first of six modules has already arrived in France. It is currently sitting in the port. It will be delivered to the site where ITER is being assembled by the end of autumn.