The Princeton Plasma Physics Laboratory has unveiled MUSE, a groundbreaking stellarator fusion reactor that utilizes permanent magnets. This innovative approach, relying on 3D-printed and readily available components, presents a potentially cost-effective pathway for constructing these powerful machines. This development marks a significant step towards realizing the potential of nuclear fusion as a viable energy source.
Nuclear fusion, the process powering stars like our Sun, generates vast amounts of energy by fusing atoms, unlike nuclear fission, which splits atoms. While fission powers current nuclear reactors, fusion remains a scientific frontier. Even upon achieving sustained fusion reactions, scaling the technology for commercial viability presents another substantial challenge.
Stellarators, twisty devices containing high-temperature plasmas, are designed to facilitate fusion reactions. Similar to doughnut-shaped tokamaks, stellarators differ in their magnetic field generation. Tokamaks employ solenoids, magnets requiring electric current, whereas MUSE leverages permanent magnets.
“Using permanent magnets revolutionizes stellarator design,” explains Tony Qian, a graduate student at the Princeton Plasma Physics Laboratory and lead author of publications detailing MUSE in the Journal of Plasma Physics and Nuclear Fusion. “This method enables rapid testing of plasma confinement concepts and simplified device construction.”
Permanent Magnets: A Novel Approach to Fusion
Permanent magnets eliminate the need for electric current to generate magnetic fields and are commercially available. The MUSE experiment incorporates these magnets onto a 3D-printed shell.
Permanent magnets and 3D-printed shell of MUSE.Left: Permanent magnets in MUSE. Right: The stellarator’s 3-D printed shell. Photo: Xu Chu / PPPL and Michael Livingston / PPPL Communications Department
“I realized that even alongside other magnets, rare-earth permanent magnets could generate and sustain the magnetic fields required for plasma confinement and fusion reactions,” states Michael Zarnstorff, research scientist and principal investigator of the MUSE project. “This property makes this technique feasible.”
Overcoming Challenges in Fusion Energy
Last year, Lawrence Livermore National Laboratory (LLNL) achieved breakeven in a laser-induced fusion reaction, generating more energy than the lasers supplied. However, this achievement doesn’t account for the energy needed to power the entire system. Consequently, the journey towards practical fusion energy remains lengthy.
Advancements in Fusion Technology
The LLNL breakthrough employed lasers, unlike the plasma-based fusion in tokamaks and stellarators. However, advancements like MUSE’s permanent magnets and KSTAR’s upgraded tungsten diverter simplify experimental replication and high-temperature operation.
The Future of Fusion Energy
These innovations empower scientists to further explore plasma behavior, potentially realizing the ultimate goal of sustainable and scalable fusion energy. The development of MUSE marks a promising step towards achieving this ambitious objective.
