Japanese Start-Up Helical Fusion Achieves Breakthrough in Nuclear Fusion Technology

On October 27, 2025, Japanese start-up Helical Fusion announced a significant breakthrough in nuclear fusion technology by successfully testing a high-temperature superconducting (HTS) coil, a critical component for future commercial fusion reactors. This test replicated the magnetic conditions inside a fusion device and achieved stable superconducting current flow, marking a world-first achievement.

The HTS coil reached a stable superconducting current of 40 kiloamperes under a 7-tesla external magnetic field at 15 Kelvin (-258°C). This milestone paves the way for the construction of Helix HARUKA, Helical Fusion's integrated demonstration device designed to prove the feasibility of continuous, stable fusion energy.

Founded in 2021, Helical Fusion builds upon over 60 years of expertise in the Helical Stellarator approach from Japan's National Institute for Fusion Science (NIFS). The company's leadership includes CEO Takaya Taguchi and co-CEO Junichi Miyazawa, a nuclear physicist from Nagoya University.

In July 2025, Helical Fusion closed its Series A funding round, securing ¥2.3 billion (approximately $15 million). This brings the company's total capital—including grants and loans—to ¥5.2 billion (approximately $35 million). The funding aims to accelerate the "Helix Program," a roadmap toward a steady-state net power fusion plant in the 2030s. Investors include SBI Investment, Keio Innovation Initiative (KII), and 17 other institutions, alongside individual investors and public financial institutions.

CEO Takaya Taguchi emphasized the need for increased government funding, noting that Japan's investment of 100 billion yen is significantly lower than the over one trillion yen spent by the U.S. and China. With strong political backing from Japan's Prime Minister Sanae Takaichi, Helical Fusion seeks to lead global progress in fusion power.

The successful development of commercial fusion energy has profound social and economic implications. Fusion energy offers a potential source of abundant, zero-carbon baseload power, addressing global electricity demand projected to rise sharply by 2050. Analysts project a $550 billion annual market for fusion by mid-century. Helical Fusion's advancements contribute to Japan's energy security, potentially transforming the nation from an energy importer to an energy exporter.

Globally, approximately 50 fusion projects are striving to produce stable, net-positive fusion energy with regular maintenance capability. Helical Fusion's focus on the Helical Stellarator design differentiates it from other approaches, such as tokamaks or laser-based fusion, by enabling inherently stable, continuous plasma operation.

Helical Fusion's recent achievement marks a significant step toward commercial fusion energy. Continued investment and government support are crucial for Japan to secure a leading role in the global fusion energy race.