Helical Fusion's 2027 Test and the UK's 59 Megajoule Shot

Helical Fusion, a Japanese startup, says it will begin preliminary power-on tests at its demonstration fusion reactor in 2027. The company disclosed the timeline on 29 September, when it opened the construction site to reporters, according to The Asahi Shimbun.

The machine, Helix HARUKA, sits at the National Institute for Fusion Science (NIFS) in Toki, Gifu Prefecture. It is described as Japan's first integrated pilot reactor built on the helical approach, a design that twists magnetic field lines to confine plasma. Construction of the first spiral coil began early this year and is now largely complete. That is the near-term claim. The longer arc is more cautious. Helical Fusion said that if first-stage tests succeed it will install a second coil and major components, including a liquid-metal wall blanket, before power-on tests of the completed integrated facility around 2030.

The company's chief executive, Takaya Taguchi, told reporters it aims to build a commercial power plant as early as the 2040s. He also said hurdles remain beyond engineering, naming cost, safety and construction speed.

Helical Fusion is the sole private-sector inheritor of helical fusion technology developed at NIFS, one of the world's largest fusion research facilities. The company completed a performance test of a high-temperature superconducting (HTS) coil in 2025, replicating the magnetic environment inside a fusion device and achieving stable current flow under superconducting conditions, which it called a world first. That result, the company said, cleared a key hurdle for manufacturing the integrated demonstration reactor.

The power output question

What the field still lacks is a machine that produces more energy than it consumes. The most-cited recent data point predates this week's news: the Joint European Torus (JET) near Abingdon in Oxfordshire generated around 59 megajoules, or 11 megawatts of energy, in a five-second burst. London Daily reported the figure and noted the experiment still consumed more energy to create the reaction than the reaction released.

Professor Ian Chapman, chief executive of the UK Atomic Energy Agency, which co-funds and operates JET, called the results a landmark. Professor Ian Fells of the University of Newcastle called 59 megajoules of heat energy over five seconds a landmark in fusion research. Professor Sue Ions, a nuclear engineer and fellow of the Royal Academy of Engineering, said the results give confidence that the prize of fusion energy is worth pursuing. All three comments come via London Daily's account.

The scale is worth holding onto. JET heats deuterium and tritium to 150 million degrees Celsius, forming a plasma about 10 times hotter than the sun. That is the reaction that produced the 59 megajoules. Helical Fusion's HARUKA is a much smaller step, and its own 50 MW follow-on machine, HELIX KANATA, is still a 2030s investment plan.

Money is moving faster than the physics

Public and private funding announcements have arrived in a cluster. Japan's government has designated fusion energy as one of 17 strategic sectors and plans to invest 3.1 trillion yen, about $19.7 billion, through public and private funding by the 2040 financial year, according to Asahi. Prime Minister Sanae Takaichi is described as a strong supporter of the industry.

In the United States, The Fusion Report says House Science Committee Ranking Member Zoe Lofgren and Subcommittee Chair Jay Obernolte introduced the bipartisan American Leadership in Fusion Act. The bill would provide $10 billion to commercialize fusion energy, including $3.8 billion for materials and fuel cycle test facilities, $3 billion for a new milestone-based demonstration program and $2 billion for the existing milestone program.

The same outlet reports that China's ENN Group broke ground on Helong-2, a hydrogen-boron fusion platform in Hebei Province, with experiments expected by the end of 2027 and first hydrogen-boron fusion electricity targeted for 2030. Proxima Fusion and the State of Lower Saxony agreed to build Europe's first large-scale fusion-grade HTS tape factory, with around €140 million planned for the first two phases through 2029 and €21 million committed by the state.

Supply chain deals are following. Commonwealth Fusion Systems placed its largest single purchase order of HTS tape with Fujikura, according to the company's news page, and has raised a further $1 billion, bringing total capital raised to $4 billion. The company also signed a collaborative research agreement with A*STAR in Singapore and became the first fusion company to apply to PJM Interconnection, the largest US wholesale electricity market.

Not every number points the same way. The Fusion Report notes that aneutronic approaches such as D-He3, backed by Helion Energy, and p-B11, planned by TAE Technologies, Marvel Fusion and HB11 Energy, can use the same thermal cycle or direct energy conversion. Direct conversion has been demonstrated but is not production-ready. In D-T fusion, the 14.1 MeV neutron carries roughly 80% of the total energy into a thermal blanket, where heat drives a turbine and generator, a mechanism in use for over 140 years.

Hiring reflects the shift. The Fusion Report describes Inertia's appointment of Sam Crisafulli as chief systems engineer after 29 years of senior and executive experience, including 12 years with ASML's plasma generation and energy control group, as one example of crossovers from semiconductor, aerospace, fission, chemical processing, LNG and utility backgrounds.

None of this changes the central uncertainty. Seventy years of research have yet to yield a commercially viable reactor, as Asahi noted in its report. Helical Fusion's 2027 test is a power-on test, not a power-plant milestone, and the company's own chief executive lists cost, safety and construction speed alongside the technical problems. For now the record remains JET's 59 megajoules, and the newest commitment is a 2027 date at a site in Gifu Prefecture.