OpenStar Technologies, a New Zealand-based fusion energy startup, has trapped plasma inside a levitated superconducting magnet, a feat that no company or laboratory had previously achieved with high-temperature superconductor technology. The experiment, which took place in New Zealand, builds on decades of government-funded research into levitated dipole confinement and signals a potential shift in how the fusion industry approaches reactor design. If the results hold up to independent scrutiny, the approach could offer a cheaper, more compact path to fusion power than the giant tokamak machines that have dominated the field for half a century.
How a Floating Magnet Holds Superheated Gas
The core idea behind a levitated dipole reactor is deceptively simple: suspend a powerful magnet inside a vacuum chamber and let its magnetic field trap a ring of hot, ionized gas around it. Because the magnet floats freely rather than resting on a physical support, there is no solid structure in contact with the plasma to erode or contaminate. That eliminates one of the most stubborn engineering problems in fusion, where plasma hot enough to fuse atomic nuclei tends to destroy whatever material it touches. The concept draws direct inspiration from planetary magnetospheres, where natural magnetic dipoles confine charged particles in stable belts without any walls at all.
OpenStar’s device uses a magnet wound from high-temperature superconducting tape, a significant departure from earlier experiments that relied on conventional low-temperature superconductors requiring extreme cooling. According to a release from Faraday Factory, the magnet coils used high-temperature superconductor tape supplied by the company, and the system achieved first plasma in October 2024 with a reported temperature of 300,000 degrees Celsius sustained for 20 seconds. A separate account from Bloomberg described OpenStar floating a half-tonne magnet in a vacuum chamber of glowing gas heated to more than a million degrees Celsius. The discrepancy between 300,000 degrees Celsius and more than a million degrees Celsius has not been publicly reconciled, and no independent peer-reviewed measurement of the plasma parameters has been published.
From MIT Lab to New Zealand Startup
OpenStar did not invent the levitated dipole concept. That distinction belongs to the Levitated Dipole Experiment, or LDX, a joint MIT-Columbia project funded by the U.S. Department of Energy. Principal investigators Jay Kesner and Michael Mauel began the program in the late 1990s, and LDX eventually produced the first experimental evidence that plasma confined by a levitated dipole magnet exhibits a turbulent inward pinch, a counterintuitive effect in which turbulence drives plasma density toward the magnet rather than dispersing it outward. That finding, published in Nature Physics, demonstrated that levitated dipoles could achieve a form of self-organized confinement fundamentally different from the brute-force magnetic cages used in tokamaks.
OpenStar is a fusion startup linked to high-temperature magnet research at New Zealand’s Robinson Research Institute. What the company added to the LDX legacy was the switch to modern high-temperature superconductors, specifically ReBCO (rare-earth barium copper oxide) tape. A technical paper describing the related APEX-LD device, a compact levitated dipole built for electron-positron pair plasma confinement, reports a persistent current of roughly 60 kA-turns and an axial field of about 0.5 tesla, with levitation times exceeding three hours. Those figures matter because they show that a relatively small superconducting coil can sustain the magnetic field strength and stability needed to hold plasma without external power input for extended periods, an essential requirement for any practical reactor based on this geometry.
Why the Temperature Dispute Matters
The gap between the two reported plasma temperatures is not a minor footnote. In fusion science, temperature is directly tied to how close a plasma is to the conditions needed for self-sustaining nuclear reactions. Deuterium-tritium fusion, the reaction most commercial projects target, requires ion temperatures on the order of 100 million degrees Celsius. A plasma at 300,000 degrees is roughly 300 times too cool; a plasma above one million degrees is still far short but represents a different class of experiment entirely. Without a peer-reviewed diagnostic report from OpenStar, outside physicists cannot assess which figure is closer to reality or whether the measurements refer to different plasma species (electrons versus ions, for instance), different regions of the device, or different operating shots.
This ambiguity is common in early-stage fusion announcements, where companies face pressure to publicize milestones before full data review. The LDX program, by contrast, operated for years under Department of Energy oversight and produced a final report documenting its campaigns with quantitative claims about pulse length, plasma beta, and stability limits. OpenStar has not yet released an equivalent technical record for its October 2024 trial. Until it does, the most defensible reading of the evidence is that the company demonstrated stable levitation and plasma formation in a dipole geometry using high-temperature superconductors, a genuine first, but that the performance envelope of the machine (its true temperatures, densities, and confinement times) remains uncertain.
The Role of Open Science Infrastructure
Behind the scenes of these fusion milestones is a global research infrastructure that quietly shapes how fast ideas spread and how well claims can be checked. The APEX-LD paper that documents key parameters of a levitated high-temperature superconducting dipole was shared through arXiv’s open-access platform, allowing plasma physicists worldwide to examine design choices, reproduce calculations, and compare OpenStar’s hardware to earlier LDX-era devices. Because arXiv preprints are available without paywalls, they make it easier for independent researchers, including those outside major national laboratories, to scrutinize ambitious performance claims and propose alternative diagnostics or configurations.
That openness depends on a modest but carefully maintained ecosystem. The service is supported by a network of institutional members, universities, laboratories, and libraries that contribute financially and help guide policy. Individual scientists and interested members of the public can also donate directly to keep servers running and to fund improvements in moderation, search tools, and long-term preservation. For researchers in specialized areas like levitated dipole fusion, this infrastructure is not just a convenience. It is often the only practical way to access detailed technical designs quickly enough to influence ongoing experiments at small startups and academic labs.
What Comes Next for Levitated Dipole Fusion
For OpenStar and other proponents of levitated dipole fusion, the next steps are as much about process as physics. To move beyond headline-grabbing temperature claims, the company will need to publish diagnostic methods, error bars, and full operating conditions in venues where domain experts can respond. Preprint servers provide submission guidance and moderation rules that are designed to balance rapid dissemination with basic quality control, and following those norms would help place OpenStar’s work in a continuum with LDX and APEX-LD rather than in a separate realm of corporate marketing. Formal peer review in journals remains the gold standard. Early access to data via preprints can accelerate the cycle of critique and refinement that ultimately determines whether a fusion concept is viable.
At the same time, the broader fusion community will be watching whether levitated dipoles can scale. The APEX-LD results suggest that high-temperature superconducting coils can maintain strong dipole fields for hours, but turning that capability into a net-energy device requires orders-of-magnitude jumps in plasma pressure and confinement. Those challenges are daunting, yet the history of LDX shows that this geometry can produce counterintuitive, self-organizing behavior that differs from tokamaks in potentially advantageous ways. If OpenStar can combine that physics with transparent reporting and independent validation, its floating magnet in a New Zealand vacuum chamber may mark not just a clever demonstration, but the early outline of an alternative path to fusion power.
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*This article was researched with the help of AI, with human editors creating the final content.
