Helix HARUKA is a high-magnetic-field helical stellarator being developed by Helical Fusion in Japan. It will deploy high-temperature superconductor (HTS) magnets together with a liquid-metal (LM) wall/blanket system in a power-plant-relevant configuration. The primary KPIs for HARUKA are successful system integration of the HTS magnet system and LM blankets into a single fusion machine, and demonstration of long-duration, steady-state plasma operation targeting continuous runs of more than 24 hours. Helix HARUKA is not designed to generate electricity; instead, it will serve as the integrated physics-and-engineering testbed that de-risks and validates the core technologies required for the Helix KANATA power plant.

Helical Fusion has been constructing Helix HARUKA with the aim of operating it around 2030 as a key milestone on its roadmap toward commercial stellarator fusion.

Helix KANATA is a next-generation helical stellarator fusion pilot plant concept that builds directly on the technologies demonstrated in Helix HARUKA. KANATA is designed as a fully integrated fusion power plant, combining HTS stellarator magnets, a liquid-metal breeding blanket, tritium fuel-cycle systems, heat-extraction loops, and turbine-based balance-of-plant to generate net electricity on a continuous, steady-state basis. The goal of the Helix KANATA device is to serve as a commercial-scale, zero-carbon fusion power plant capable of supplying reliable baseload electricity and high-grade heat for industrial users.

Helical Fusion currently aims to bring the first Helix KANATA plant into operation in the 2030s, following successful achievement of the key performance targets on Helix HARUKA.

The Large Helical Device (LHD) is a superconducting helical stellarator (heliotron) operated by the National Institute for Fusion Science (NIFS) in Japan. Since beginning operation in 1998, LHD has pursued steady-state, high-temperature plasma confinement as a pathfinder for helical stellarator fusion approach. It has demonstrated plasmas with ion and electron temperatures reaching over 100 million degrees Celsius, establishing reactor-relevant high-temperature operation in a stellarator configuration. LHD was constructed on time and on budget through the efforts and capabilities of Japanese engineering companies, demonstrating Japan’s strength in large-scale, high-precision fusion engineering.

LHD has also set landmark records for long-pulse operation, sustaining high-temperature plasmas for more than 3,000 seconds (about one hour), thereby experimentally demonstrating steady-state capability with superconducting coils and continuous heating systems. In terms of overall performance, LHD has achieved fusion triple products exceeding 10¹⁹ keV·s/m³, in the same order of magnitude as the high-performance discharges reported on Germany’s Wendelstein 7-X stellarator, underscoring the competitiveness of the stellarator approach to magnetic confinement fusion.