Superconducting magnets discovered by MIT scientists in 2021 are finally ready for fusion reactors, some scientists say. The new type of magnet was developed by researchers at the Plasma Science and Fusion Center (PSFC) at MIT. The researchers have now published several papers on the discovery, confirming that the magnets can meet the challenging conditions of a fusion power plant.
Unlocking the power of nuclear fusion has been a long-standing goal for scientists hoping to harness the energy that fusion generates to create a clean energy source that can replace fossil fuels and dangerous nuclear fission operations.
The idea of emulating nuclear fusion like that seen in the sun could completely unlock “limitless energy” for humanity to take advantage of. But it’s not as easy as some had hoped it would be. It takes extremely powerful magnets to hold the fusion fuel in place. That’s where these recently discovered superconducting magnets come into play.
Similar magnets are currently in operation at the Tokamak fusion reactor, where they have to maintain four degrees Kelvin (-270 degrees Celsius) to operate. After years of trying, scientists are finally managing to extract a little more energy from the reaction than they are putting in.
But, these new superconducting magnets are designed to function at 20 Kelvin (-253 degrees Celsius). They’re made from rare-earth barium copper oxide (REBCO), and the researchers who developed them say they have several advantages compared to the other materials used to create similar magnets.
One major difference with these REBCO magnets is that they require less insulation than other superconductor-based magnets. Many conventional magnets of this type are insulated similarly to electrical wires. However, REBCO was left bare, allowing for greater conductivity.
This allowed the team at MIT to create a low-voltage system that’s extremely easy to fabricate. The researchers say it also allows for additional applications, like adding cooling structures or even structures for strength. The researchers had to put it through the works to determine if the magnet was ready for the next steps.
To do this, they created unstable conditions like overheating and even switched off the power supply to the cooling setup. This is one of the worst scenarios a fusion reactor can experience, and it often results in the destruction of the magnet itself. These tests helped the researchers hone their design and determine the best design for the magnet.
From here, they say that the REBCO superconducting magnets are ready to be used in an actual fusion reactor. They’ll be used extensively to help build the SPARC fusion reactor for Commonwealth Fusion Systems in Devens, Massachusetts. Their findings are published in a special edition of IEEE Transactions on Applicated Superconductivity.
