Japan's nuclear fusion firm begins building its first demonstrator

Japanese nuclear fusion startup Helical Fusion Co., Ltd., founded in 2021 as a spin-off from the National Institute of Fusion Science (NIFS), has commenced construction of its first integrated demonstration device, Helix Haruka. This marks Phase 1 of their project, focusing on assembling and validating a non-planar helical high-temperature superconducting magnet system, with energization tests planned for 2027. Helical Fusion aims to develop fusion energy technology using the stellarator approach, which differs from the more common tokamak design by employing a twisted torus-shaped vessel for plasma confinement. NIFS operates the Large Helical Device (LHD), a leading stellarator research facility that has demonstrated sustained plasma operation for over 54 minutes, providing critical expertise for Helical Fusion’s efforts. Helical Fusion’s demonstration plant development is structured into three phases: Phase 1 involves testing the magnet system; Phase 2 will integrate the magnet with core subsystems and the power-generating system Helix