A Japanese startup commercializing the heliotron stellarator concept — building on the Large Helical Device's decades of plasma research.
Helical Fusion is a Japanese fusion energy startup founded to develop a commercial fusion reactor based on the heliotron concept, a variant of the stellarator family of magnetic confinement devices. The company builds on Japan's extensive heliotron research heritage, particularly the Large Helical Device (LHD) operated by the National Institute for Fusion Science (NIFS) in Toki, Gifu Prefecture.[1]
The heliotron configuration uses a continuous helical coil wound around a toroidal vacuum vessel to generate the confining magnetic field. Like other stellarators, it does not require a net toroidal plasma current for confinement, providing inherent steady-state capability and freedom from current-driven disruptions. The LHD has demonstrated high-performance plasmas with ion temperatures exceeding 10 keV and long-duration discharges lasting up to 48 minutes.[2]
Helical Fusion aims to translate this physics basis into a compact reactor design, potentially incorporating modern high-temperature superconducting materials to reduce device size and improve economic performance.
Japan has maintained one of the world's strongest stellarator/heliotron programs for over four decades, with the LHD serving as a flagship experiment since its first plasma in 1998. Helical Fusion benefits from this deep national expertise and from Japan's broader fusion strategy, which includes both public and private pathways to fusion energy.[3]
Helical Fusion represents the commercial extension of Japan's decades-long heliotron research program. The company must demonstrate that the heliotron configuration can be optimized for reactor-relevant performance while achieving the engineering simplicity and cost targets demanded by the energy market.