OpenStar Technologies: levitated-dipole fusion, Junior and Tama Nui

OpenStar Technologies is a New Zealand company developing fusion machines that confine hot plasma around a magnet suspended in mid-air. It aims to supply dependable electricity and extend its technology to medical-isotope production using neutrons. It is currently experimenting with a prototype and designing subsequent machines, activities that must be distinguished from commercial power generation or mass production of medical isotopes.

OpenStar was founded in Wellington, New Zealand, in 2021. Its approach is the levitated dipole: a superconducting ring magnet floats at the center of a vacuum vessel, retaining plasma in the surrounding magnetic field. The arrangement of magnet and plasma differs from approaches that surround plasma with numerous external coils. Company and team

Levitation is more than a visual feature. It avoids support structures crossing the plasma. However, it creates distinctive engineering challenges in supplying power and cooling to the central magnet. Explanation of the approach

The persistence of plasma in magnetospheres, including Earth's, inspired the approach. The company traces its research lineage to Akira Hasegawa's 1987 proposal, MIT and Columbia University's LDX, and the University of Tokyo's RT-1.

Dipole research explores how transport driven by plasma fluctuations can shape density and temperature profiles. The existence of magnetospheric plasma, however, does not prove that a compact laboratory device meets the conditions for electricity generation. Results from other institutions must not be counted as OpenStar's own achievements. Inspiration from nature and earlier laboratory experiments

According to the company's FAQ, the first prototype, Junior, was built, tested and brought to first plasma in under two years for less than US$10 million. These are company-reported development time and cost figures. First plasma marks the start of experimentation with a machine, not demonstrated fusion gain or electricity delivery. Project-status FAQ

A PPPL announcement dated 29 September 2026 describes completion of Junior's commissioning and the unveiling of the design for a grid-scale machine, Tama Nui. Operating a prototype, designing a future machine and completing a power plant cannot be merged into one achievement. The displayed Tama Nui model is not a photograph of an operating power station. PPPL announcement

A levitated magnet must carry the functions it needs for operation. OpenStar describes two enabling technologies: a superconducting power supply, or flux pump, to compensate for losses from small residual resistances such as those at joints; and a cryogenic solid–liquid mixture held in a reservoir on the magnet.

The magnet is cooled, operated and recooled after absorbing heat. Cooling downtime and durability under repeated temperature changes therefore matter. Explaining a route toward high availability is different from demonstrating that availability in a power station. Magnet power and cooling

OpenStar also describes developing a neutron source to supply radioisotopes for medicine. Its official page lists candidates including Mo-99 and Lu-177. Listing an isotope does not mean its mass production and delivery have already been accomplished.

A neutron-use facility requires a different assessment from a generating station. Quantities, purity, irradiation and separation processes, quality control and reliable supply must be established. Producing neutrons, achieving facility-wide net electricity and delivering a product usable in medicine each require separate evidence. Isotope business

OpenStar and the Princeton Plasma Physics Laboratory (PPPL) signed a memorandum of understanding for research, academic and educational cooperation in levitated-dipole science and technology. It connects the company with research expertise and facilities; it is not a commercial-generation guarantee, government product certification or equipment purchase contract. Cooperation announcement

When assessing research, experimental papers, design papers, conference posters and company explainers must also be distinguished. The company's bibliography includes Junior's initial results as well as design status for the next-generation Tahi experiment and work on neutron shielding, superconducting power supplies and radiation tolerance of optical fibers. Technical-resource index

Future assessment must establish how plasma temperature, density and confinement coexist under the same experimental conditions, as well as the central magnet's cooling, position control and radiation tolerance. Fuel systems, heat recovery, maintenance downtime and repeated operation must be integrated before the system can be evaluated as a power station.

The company's FAQ sets a goal of a power-generating device in the 2030s. This is a future plan, not a guaranteed delivery or operating date. Editorial updates should separately track Junior measurements, construction and operation of successor machines, and concrete milestones for electricity and isotopes. Project-status FAQ

Checked on 30 October 2026 using the official primary sources linked in the text. Full papers linked from the technical-resource index were outside this review's retrieval scope; no independent full-paper assessment is claimed. Reproduction rights for equipment photographs and model images are managed separately from fact-checking the text.