It’s Announced. Fusion and Medical Device Technology Will Develop With New Magnet

In an article published in Superconductor Science and Technology, scientists announced that they have designed a type of magnet that can be used in a variety of devices, from fusion plants known as tokamaks to medical machines that create detailed pictures of the human body.

Tokamaks work with a central electromagnet, known as a solenoid, to create electric currents and magnetic fields in plasma, the hot and charged state of matter made up of free electrons and atomic nuclei, resulting in infusion reactions. But over time, the insulation surrounding the wires of the electromagnet can deteriorate after exposure to various subatomic particles, reducing the tokamak’s ability to harness its fusion power.

In this new type of magnet, the metal acts as insulation and absorbs the effect of particles. It can also operate at higher temperatures than existing superconducting electromagnets.

Fusion combines light elements in the form of plasma to produce large amounts of energy. And scientists are trying to replicate fusion on Earth, an almost inexhaustible source of power to generate electricity.

“Our innovation both simplifies the fabrication process and makes the magnet more tolerant of the radiation produced by the fusion reactions,” said Yuhu Zhai, chief engineer at the US Department of Energy’s Princeton Plasma Physics Laboratory and lead author of the paper.

Yuhu Zhai, a principal engineer at PPPL

“If we are designing a power plant that will run continuously for hours or days, then we can’t use current magnets,” Zhai said. In these facilities, which will produce particles with higher energy than the existing experimental facilities, the magnets in production today will no longer be valid.”

An electromagnet is a magnet made from iron using an electric current. Both ends of the electromagnet attract magnetic materials. Electromagnets are used in a variety of places, from tokamaks to cranes that lift cars that break down in landfills, to magnetic resonance imaging devices that scan the inside of the human body.

“Scientists typically only use 70 percent of the superconducting wire electrical current capacity when designing and building high-power magnets,” he said. “And large-scale magnets like those used in ITER, the international fusion facility being constructed in France, often use only 50 percent”.

Details of the magnet

The magnet in question has wires made of the elements niobium and tin, which when heated in a special way form a superconductor that allows electric current to flow without resistance at extremely low temperatures. Therefore, much less insulation is needed to prevent current leakage, according to Phys.

Robert Ellis, PPPL Chief Engineer, said: “This new concept is interesting because it allows the magnet to carry a lot of electrical current in a little space, reducing the amount of volume the magnet occupies in a tokamak.”

“This magnet could also operate at higher current densities and stronger magnetic fields than magnets can today. Both qualities are important and could lead to lower costs,” Ellis added.