OpenStar Technologies, a New Zealand-based fusion startup, has reported producing its first plasma in a levitated dipole experiment, a design that departs sharply from the tokamak reactors that dominate mainstream fusion research. The company’s “Junior” experiment, detailed in a peer-reviewed paper and a preprint, represents an early but concrete step in testing whether a magnetically levitated coil can confine hot plasma well enough to eventually produce net energy. The achievement, which took place in late 2024, puts OpenStar among a small group of private ventures betting that alternative reactor geometries can reach commercial fusion faster than the massive international projects now under construction.
What the Junior Experiment Actually Did
The core of the Junior experiment is a high-temperature superconducting magnet built with REBCO (rare-earth barium copper oxide) tape, generating a field of 5.6 tesla. That magnet sits inside a 5.2-meter vacuum chamber, and plasma is heated using 50 kilowatts of electron cyclotron resonance heating (ECRH), according to a journal article in Fusion Engineering and Design. The paper, authored by the OpenStar team, reports first plasmas in late 2024 and outlines plans for levitating the magnet inside the chamber, a step that would eliminate the physical supports currently holding it in place and reduce plasma losses caused by contact with solid structures.
A preprint of the same work is available on arXiv under ID 2508.17691, providing open access to the technical details for researchers outside the journal’s subscriber base. The preprint record also allows tracking of any revisions between the initial submission and the final peer-reviewed version, though no publicly documented differences have been flagged so far. Together, the two publications give outside observers a relatively rare, detailed look inside a private fusion company’s hardware and operating parameters.
Why a Levitated Dipole Is Different
Most fusion efforts worldwide, from giant government-backed collaborations to well-funded startups, rely on tokamak or stellarator designs. These use external magnetic coils arranged around a doughnut-shaped chamber to squeeze plasma into a tight ring. The approach works, but it comes with well-known problems: plasma instabilities at the edges, enormous engineering complexity, and the need for extremely precise magnetic field shaping to prevent the plasma from touching the walls.
A levitated dipole takes a fundamentally different approach. Instead of wrapping coils around the outside of a chamber, it suspends a single superconducting magnet inside the vacuum vessel itself. Plasma then forms around the floating coil, confined by the dipole magnetic field in a way that resembles how charged particles behave around planets like Jupiter. The theoretical advantage is that this geometry can tolerate higher plasma pressure relative to magnetic pressure, a ratio physicists call “beta.” Higher beta means more energy output for a given magnet strength, which could translate to smaller, cheaper reactors if the physics holds up at scale.
In principle, the dipole configuration also offers a more naturally stable environment for the plasma core. Instead of fighting edge-localized instabilities with complex feedback systems, the field lines in a dipole tend to guide particles into closed orbits around the central magnet. That self-organizing behavior has been explored in earlier academic experiments, but OpenStar is among the first private companies to push the concept toward an eventual power plant.
The catch is that levitating a superconducting magnet inside a hot plasma environment is an unsolved engineering problem at reactor scale, The Junior experiment has not yet achieved levitation; according to the Fusion Engineering and Design paper, levitation is planned but has not been demonstrated. The current results come from a supported configuration, meaning the magnet is physically held in place by mechanical structures that interfere with plasma confinement. Removing those supports without compromising stability or safety is the next major technical hurdle.
Supply Chain Signals and Independent Confirmation
One piece of third-party corroboration comes from Faraday Factory, a Japan-based manufacturer of high-temperature superconductor tape. In a release distributed through a press statement, Faraday Factory stated that its superconductors were used in the magnet coils and that OpenStar achieved first plasma in October 2024. That specific month adds precision to the “late 2024” timeframe cited in the academic paper, tightening the public record around when the milestone occurred.
The supplier’s statement also introduces a slight tension in terminology. Faraday Factory describes the device as a “levitated dipole fusion prototype,” while the technical paper makes clear that levitation has not yet occurred and is a planned upgrade. This is not necessarily a contradiction. The experiment is designed for levitation and named accordingly, but the first plasma results were collected with the magnet still mechanically supported. Readers and investors should note the distinction: the machine is built to levitate, but it has not done so yet.
The involvement of Faraday Factory as a named supplier is itself a useful data point. Fusion startups often keep their supply chains private, and the willingness of a component manufacturer to publicly claim credit suggests confidence in the experiment’s legitimacy. It also signals that the high-temperature superconductor industry, still relatively small, sees levitated dipole research as a credible market for its products. The press distribution through the broader PR Newswire ecosystem further amplifies that message beyond the niche fusion community.
What the Results Do and Do Not Prove
Producing first plasma is a standard early milestone in any fusion experiment. It means the machine can ionize gas and sustain a plasma state, but it says little about whether that plasma is hot enough, dense enough, or stable enough to produce significant fusion reactions. Every tokamak, stellarator, and alternative concept passes through this stage. The real tests come later: achieving sustained confinement, reaching fusion-relevant temperatures (typically above 100 million degrees Celsius), and eventually demonstrating net energy gain.
OpenStar’s results are best understood as proof that the Junior hardware works as designed at a basic level. The 5.6-tesla magnet held its field, the ECRH system delivered energy to the plasma, and the vacuum chamber maintained conditions suitable for plasma formation. These are necessary but not sufficient conditions for a viable fusion reactor. The company has not published detailed plasma temperature or density measurements from the October 2024 runs in the currently available versions of the peer-reviewed paper or the associated documentation, leaving open questions about how close the experiment is to fusion-relevant regimes.
The planned levitation phase will be far more revealing. If OpenStar can float the superconducting coil inside the chamber while maintaining a stable plasma, it will demonstrate that one of the most challenging mechanical aspects of the concept is at least experimentally tractable. Levitation should also reduce the amount of solid material intersecting the magnetic field lines, cutting down on energy losses and impurity influx from the supports. That, in turn, would allow clearer measurements of confinement times and plasma behavior in a geometry closer to a full-scale reactor.
Even then, many unknowns will remain. Scaling laws for dipole confinement are less mature than those for tokamaks, and it is not yet clear how performance will change as devices grow larger or operate at higher power. Engineering issues around cryogenics, quench protection for the REBCO magnets, and long-term material durability in a neutron-rich environment also lie well beyond what the Junior experiment can address. For now, the results show that OpenStar can build and operate a complex superconducting device, not that it can beat more established fusion approaches on cost or timeline.
How to Read the Milestone
For policymakers, investors, and technically minded observers, the key is to place OpenStar’s announcement in context. First plasma in a novel geometry is a meaningful step, especially when documented in a peer-reviewed venue and mirrored in an openly accessible preprint record. Independent confirmation from a named supplier adds credibility, and the use of commercially produced REBCO tape hints at a pathway from bespoke laboratory hardware toward more standardized industrial components.
At the same time, the gap between a successful physics experiment and a grid-scale power plant remains enormous. Tokamak-based projects have spent decades climbing that ladder and are only now approaching the conditions needed for sustained net energy. Alternative concepts like levitated dipoles promise shortcuts, but they also introduce fresh unknowns. OpenStar’s Junior device is an early probe into that landscape, not a proof that the route will be shorter.
In practical terms, the next few years will likely determine whether levitated dipole fusion can move from intriguing theory to competitive technology. Demonstrating stable levitation, publishing quantitative confinement data, and outlining a credible scaling strategy will be the milestones to watch. Until then, OpenStar’s first plasma should be seen as an encouraging sign that the company can execute on complex hardware, rather than as evidence that commercial fusion is imminent.
More from Morning Overview
*This article was researched with the help of AI, with human editors creating the final content.
