Nuclear fusion promises virtually unlimited energy and freedom from the harmful impact of fossil fuel consumption.
Now, researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have announced they’ve found a way to build powerful magnets much smaller than ever before, a press release reveals.
The new innovation could contribute to the development of tokamak reactors, unlocking the potential of nuclear fusion.
We are on the eve of a viable nuclear fusion
Scientists have found a new method to build high-temperature superconducting magnets that are made of a material that conducts electricity with virtually no resistance at hotter temperatures than before. Smaller magnets will fit more easily inside spherical tokamaks, which are being investigated as a potential alternative to more conventional doughnut-shaped tokamaks.
Fusion scientists and engineers use these incredibly powerful magnets to control and maintain the hot plasma necessary for the nuclear fusion reaction. Basically, the new magnets could be placed separately from other machines in the central cavity of the spherical tokamak. This means that scientists could repair them without having to disassemble other parts of the tokamak.
“To do this, you need a magnet with a stronger magnetic field and a smaller size than current magnets,” explained Yuhu Zhai, senior engineer at PPPL and lead author of a paper on the new magnets published. in IEEE Transactions on Applied Superconductivity. “The only way to do it is with superconducting wires, and that’s what we did.”
The magnets could also allow scientists to develop smaller tokamaks, which could improve performance and reduce construction and operating costs. “Tokamaks are sensitive to conditions in their central regions, including the size of the central magnet, or solenoid, shielding and vacuum vessel,” said Jon Menard, PPPL’s deputy director of research. “It depends a lot on the center. So if you can scale things down in the middle, you can scale down the whole machine and reduce costs while theoretically improving performance.”
New technique makes magnets cheaper, smaller and more powerful
The new magnets were designed using a technique developed by Zhai and his colleagues at Advanced Conductor Technologies, University of Colorado, Boulder, and the National High Magnetic Field Laboratory, Tallahassee, Florida. They’ve developed a technique that doesn’t require traditional epoxy and fiberglass insulation for their magnet wires, allowing them to downsize.
By removing epoxy from the equation, the researchers are also reducing the cost of producing the magnets, which will also result in cheaper tokamaks. Coil winding costs are much lower because we don’t have to go through the costly and error-prone epoxy vacuum impregnation process,” Zhai said. “Instead, you wind the conductor directly into the shape of the coil.
Smaller magnets will, in theory, allow for more tokamak design iterations, as they can be more easily placed in different locations, allowing for more configurations. We may still be a long way from seeing the first fully operational fusion reactor, but this new development brings us one step closer to commercially viable nuclear fusion.