Helical Fusion marks milestone in progress toward fusion power

Helical Fusion, a Japan-based fusion start-up that is developing a stellarator fusion power reactor, has announced it has successfully demonstrated its high-temperature superconducting (HTS) coil under relevant magnetic conditions.

A video highlighting the stellarator's technology testing can be found here.

Next step: Having completed performance testing of the HTS coil, Helical Fusion will now begin manufacturing and construction of its integrated demonstration helical axis stellarator, called Helix Haruka. That device will inform the development of the company's planned fusion pilot plant, Helix Kanata, planned for commercial deployment in the 2030s, according to the company.

Helical Fusion was founded in 2021 with technology spun out of Japan's National Institute for Fusion Science (NIFS). In July, the company secured ¥2.3 billion ($15.6 million) in venture capital financing, bringing its total capital investment-including grants and loans-to ¥5.2 billion ($35.3 million).

The test: According to Helical Fusion, the performance testing marks the world's first successful demonstration of an HTS coil constructed with a fully functional large-scale conductor:

The coil is based on a conductor cable designed for a commercial fusion power plants' scale use.

The test replicated the magnetic environment inside a fusion device, including both self-generated and external magnetic fields.

A current test was conducted under superconducting conditions.

Using NIFS's large-diameter, high-field testing facility, the conductor reached stable superconducting current flow at 40 kA under a 7-tesla external magnetic field at 15 K (−258°C), the company said.

In addition to HTS coil testing, Helical Fusion intends to complete performance tests of its integrated blanket/divertor system-the stellarator's second key technology-by the end of the decade under the company's Helix Program. The liquid metal-based blanket/divertor system will be tested using Helix Haruka.