In the relentless pursuit of sustainable energy, scientists are continually pushing the boundaries of what’s possible. One such breakthrough comes from the University of Maryland, where a team led by Siena Hurwitz has developed a novel approach to optimize electromagnetic coils, a crucial component in fusion reactors. Their work, published in the journal ‘Nuclear Fusion’ (translated to English as ‘Nuclear Fusion’), could significantly impact the future of fusion energy and beyond.
Fusion reactors, like stellarators and tokamaks, use powerful magnetic fields to confine plasma, the superheated state of matter that fuels fusion reactions. These magnetic fields are generated by electromagnetic coils, which experience immense forces due to the interaction of electric currents and magnetic fields—a phenomenon known as the Lorentz force. These forces can be so strong that they can deform or even destroy the coils, posing a significant challenge in the design and operation of fusion devices.
Hurwitz, a researcher at the Institute for Research in Electronics and Applied Physics, has tackled this challenge head-on. Her team has developed a reduced model for the self-force and self-inductance of electromagnetic coils, which is both highly accurate and numerically efficient. This model allows for rapid evaluation of coil forces within an optimization loop, a process that was previously too time-consuming with conventional methods.
The team implemented this model in the simsopt stellarator design software, using it to optimize the coils of a quasi-axisymmetric stellarator. The results were impressive. “We were able to significantly reduce point-wise forces throughout the coils,” Hurwitz explained. However, this reduction came with trade-offs. As Hurwitz noted, “There’s a delicate balance between reducing coil forces and maintaining the performance of the fusion device.”
The trade-offs involve factors like fast particle losses and the minimum distance between coils and the plasma surface. For instance, reducing coil forces can increase fast particle losses, which can negatively impact the efficiency of the fusion reaction. Similarly, reducing the distance between coils and the plasma surface can increase the risk of plasma-coil interactions, which can damage the coils.
Despite these challenges, Hurwitz’s work offers a promising path forward. The optimization approach can be applied not just to stellarators, but also to tokamaks, other fusion concepts, and even applications outside of fusion. This versatility could have significant commercial impacts, potentially leading to more efficient and cost-effective fusion reactors, as well as improvements in other technologies that use electromagnetic coils.
As we stand on the brink of a fusion energy revolution, Hurwitz’s work serves as a reminder of the power of innovation and the importance of pushing the boundaries of what’s possible. Her research could shape the future of fusion energy, bringing us one step closer to a sustainable, clean energy future. The energy sector is watching closely, eager to see how this breakthrough will unfold and what new possibilities it might unlock.
