Nov 7 2018
Researchers are working together to significantly expedite the development of fusion energy in an attempt to quickly supply power to the electric grid and thus help reduce the effects of climate change.
This is a rendition of the SPARC high-field tokamak experiment, which would produce the first fusion plasma to have a net energy gain. (Image credit: Ken Filar)
The advent of high-temperature superconductors—a revolutionary technology, which can be utilized for building magnets that create more intense magnetic fields than formerly possible—may aid the scientists to achieve this objective.
Investigators are planning to apply this breakthrough technology to develop magnets at the scale needed for fusion, and then constructing what would be the first fusion experiment in the world to produce a net energy gain.
The effort is a collaborative teamwork between Commonwealth Fusion Systems and Massachusetts Institute of Technology’s Plasma Science & Fusion Center. The researchers will present their work at the American Physical Society Division of Plasma Physics meeting to be held in Portland, Oregon.
When nuclei of tiny atoms merge into larger atoms in a process that releases massive amounts of energy, fusion power is produced. These nuclei, normally heavier cousins of hydrogen known as tritium and deuterium, are positively charged and therefore feel an intense repulsion that can only be resolved at temperatures of hundreds of millions of degrees. Although it is possible to produce these temperatures, and therefore fusion reactions, in the latest fusion experiments, the conditions needed for a net energy gain are yet to be realized.
Increasing the strength of the magnets might provide a possible solution to this problem. In fusion devices, magnetic fields serve to retain these hot ionized gases, known as plasmas, insulated and separated from ordinary matter. As the field becomes stronger, the quality of this insulation also becomes more effective, implying that less space is required to keep the plasma hot. If the magnetic field in a fusion device is doubled or amplified, it will help in reducing its volume—a good sign of how much the system costs—by a factor of eight, while attaining the same level of performance. Therefore, fusion is made faster, smaller, and cheaper through stronger magnetic fields.
Fusion power plants may come to fruition if there is an innovation in superconductor technology. Superconductors are actually materials that enable currents to flow through them without any loss in energy, but they have to be extremely cold to do this. However, novel superconducting compounds are capable of operating at relatively higher temperatures than that of traditional superconductors. These superconductors are crucial for fusion and can function even when they are placed in highly powerful magnetic fields.
Although high-temperature superconductors were originally in a form that was not useful for constructing magnets, scientists have now identified new methods to develop them in the form of “ribbons” or “tapes” that render magnets with unparalleled performance. For fusion machines, the design of such magnets is not appropriate because they are rather quite small. Before building the novel fusion device, known as SPARC, the new superconductors have to be integrated into the kind of strong, large magnets required for fusion.
After the magnet is successfully developed, the subsequent step will be to build and operate the SPARC fusion experiment. SPARC will serve as a tokamak fusion device—a kind of magnetic confinement configuration analogous to several machines that are already being used.
As an accomplishment similar to the first flight of Wright brothers at Kitty Hawk, showing a total energy gain, the goal of fusion research for over six decades, could be more than sufficient to put fusion decisively into national energy strategies and eventually launch commercial development. The ultimate aim is that SPARC should be operational by 2025.