In the early hours of September 5, 2021, a groundbreaking achievement unfolded within the laboratories of MIT's Plasma Science and Fusion Center (PSFC), marking a significant milestone in the realm of fusion energy research. Engineers successfully developed a new type of magnet using high-temperature superconducting material, achieving a world-record magnetic field strength of 20 tesla for a large-scale magnet. This breakthrough holds immense promise for the realization of fusion power plants capable of generating virtually limitless power output.
The achievement was met with jubilation as the team of dedicated experimenters, after rigorous labor, celebrated the success of their endeavor. However, this triumph marked merely the beginning of an extensive process. Over the following months, the team meticulously dissected and scrutinized the magnet components, analyzed data from numerous instruments, and conducted additional test runs, pushing the magnet to its limits to uncover any potential failure modes.
This exhaustive effort culminated in a comprehensive report by researchers from PSFC and MIT spinout company Commonwealth Fusion Systems (CFS), published in a special edition of the March issue of IEEE Transactions on Applied Superconductivity. The six peer-reviewed papers within the collection detail the design, fabrication, and performance evaluation of the magnet, providing invaluable insights and lessons learned from the process.
The successful test of the magnet, as highlighted by Dennis Whyte, former director of PSFC, represents a monumental advancement in fusion research, perhaps the most significant in the past three decades. Prior to this achievement, the feasibility of fusion energy was constrained by the limitations of available superconducting magnets, which were neither practical nor economically viable. However, the demonstration of a powerful magnet at a significantly reduced size heralded a transformative shift, drastically reducing the cost per watt of fusion reactor construction overnight.
The data and analysis presented in the papers affirm the feasibility of new generation fusion devices, including the SPARC design developed by MIT and CFS, laying a solid scientific foundation for their realization. Fusion, the process powering the sun and stars, holds immense potential as a clean, sustainable energy source. However, harnessing fusion energy on Earth necessitates overcoming formidable challenges, including the development of powerful magnetic fields to confine and compress the fusion fuel.
Traditionally, fusion magnets relied on superconducting materials requiring extremely low temperatures for operation. The advent of high-temperature superconductors, such as rare-earth barium copper oxide (REBCO), presented a paradigm shift in magnet design. The integration of REBCO allowed operation at higher temperatures, simplifying engineering requirements and enhancing material properties.
The redesign of magnets utilizing REBCO material demanded innovative approaches. One notable innovation was the elimination of insulation around superconducting tape, a departure from conventional magnet designs. Despite skepticism, this bold approach proved successful, streamlining fabrication processes and enhancing performance.
The culmination of the magnet test program included deliberate stress testing to simulate worst-case scenarios, providing valuable insights into magnet behavior under extreme conditions. The data obtained validated computational models, guiding future design iterations and mitigating potential risks.
The success of this endeavor underscores the collaborative efforts between MIT and CFS, leveraging institutional knowledge, expertise, and resources. The integration of academic and private sector capabilities facilitated unprecedented achievements in fusion research, setting the stage for the realization of practical fusion power plants.
Source: Massachusetts Institute of Technology