The world’s most powerful magnet shipped to the ITER fusion reactor
The most powerful magnet in the world is shipped to France to be installed in the core of ITER, the experimental fusion reactor. It is hoped that ITER will prove the feasibility of creating fusion energy on an industrial scale by replicating the process observed in the center of our sun.
The magnet, known as the center solenoid, ships in separate parts and will measure 18 meters high, 4.2 meters wide, and weigh around 1,000 tonnes when fully constructed. With a magnetic field strength of 13 Tesla, it will be about 280,000 times stronger than the Earth’s magnetic field. For this reason, the structure in which the central solenoid is located will have to withstand forces equal to twice the thrust of a space shuttle takeoff.
The magnet will consist of six modules, each containing 43 kilometers of coiled niobium-tin superconductors. Once these coils are in place, they will be sealed with 3800 liters of epoxy and shipped to the ITER site in France from the General Atomics factory in California. The first module is coming out this month and the next one will follow in August.
ITER will be the largest fusion reactor to date once completed, with 2025 as the end goal. Engineers working on the project aim to make it the first reactor that will deliver more energy from fuel than needed to maintain the fusion reaction – the plan is to create 500 megawatts of usable energy from an input of 50 megawatts.
Fusion reactors mimic the reactions seen inside stars, where vast gravitational pressure allows pairs of hydrogen atoms to fuse and create helium atoms, releasing energy. In a fusion reactor, the gravitational pressure would be much lower than inside a star, so getting the same reaction would require much higher temperatures.
Unfortunately, the necessary temperatures above 150 million ° C would melt all known material on Earth. ITER will therefore use strong magnets to contain the reaction in a ring away from metal surfaces. Water pumped through the walls of the reactor will turn into steam and drive turbines to generate electricity. The central solenoid will generate a flow of reactive plasma around the ring, while other magnets will hold the plasma inside the ring and adjust its shape.
Unlike existing nuclear power plants, which use fission, fusion reactors do not generate radioactive waste with a long half-life and their deuterium fuel is abundant. They are also safer because any disturbance in the reaction will prevent it from stopping rather than running away uncontrollably. But harnessing fusion as an efficient energy source has proven to be much more difficult.
An earlier international effort led to the construction of the JET fusion reactor in the UK in the 1980s, which also aimed to break even, where more power was produced than was put into . other device to this target, it has not yet reached it.
The UK is also drawing up plans for a Spherical Power Generation Tokamak (STEP), a fusion nuclear power plant whose construction could begin in 2030 if costs of around £ 2 billion are funded.
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