The design and construction of machines that could help the world harness the power of the sun to create electricity without producing greenhouse has been helped by researchers at the US Department of Energy.
The scientists found a way to build high-temperature magnets that are made of material that conducts electricity with little or no resistance at higher temperatures than before. The spherical tokamaks are shaped like a cored apple and are being explored as a possible design for fusion power plants.
Researchers were able to repair the magnets without taking anything else apart because they were positioned apart from other machinery.
"To do this, you need a stronger magnetic field and a smaller size than current magnets," said Yuhu Zhai, a principal engineer at PPPL. The only way to do that is with superconductivity wires.
The hot, charged state of matter composed of free electrons and atomic nuclei creates massive amounts of energy when combined with fusion. Scientists are trying to duplicate fusion on Earth in order to have a constant source of clean and safe power.
The advantages of high-temperature magnets over copper magnets are many. Because they don't heat up as quickly, they're better suited for fusion power plants that will have to run for months at a time. The same amount of electrical current can be transmitted by superconducting wires as by a copper wire.
Scientists can use the magnets to shrink the size of tokamaks and improve performance. Jon Menard said that tokamaks are sensitive to the conditions in their central regions. It depends on the center. If you can shrink things in the middle, you can cut costs and improve performance.
Zhai and his team at Advanced Conductor Technologies, the University of Colorado, Boulder, and the National High Magnetic Field Laboratory in Florida have developed new magnets. The wires don't need glass fiber to ensure the flow of electricity, thanks to the technique. The technique reduces costs. Zhai said that the costs to wind the coil are lower because we don't have to go through the expensive and error prone vacuum-impregnation process. You are winding the conductor into the coil form.
Thomas Brown, an engineer who contributed to the research, said that high-temperature superconducting magnets can help spherical tokamak design because of the higher current density and smaller windings. Smaller, more powerful magnets give the machine designer more options to design a spherical tokamak. We're not there yet but we're close enough.
More information: Y. Zhai et al, HTS Cable Conductor for Compact Fusion Tokamak Solenoids, IEEE Transactions on Applied Superconductivity (2022). DOI: 10.1109/TASC.2022.3167343
All Rights Reserved © 2024
