Fusion reactor for just $10 million held plasma at 300,000 °C for 20 seconds

New Zealand-based OpenStar was founded by Ratu Mataira in 2021 from his Wellington apartment. And now the startup has announced that it will be able to create and maintain a plasma cloud with a temperature of about 300,000 ° C for 20 seconds in its experimental reactor. Mataira claims that, together with his collaborators, he achieved this result on the path to full-fledged thermonuclear fusion in two years, spending less than $10 million.

One of the reactor elements. Image source: OpenStar

Nuclear fusion requires much higher temperatures, but OpenStar highlights an ingenious, scalable reactor design suitable for commercialization. The prospect of nuclear fusion, in which isotopes of hydrogen collide within a plasma, releasing enormous amounts of energy, has captivated researchers for decades.

Image source: ft.com

Significant funding has flowed into fusion startups in recent years as investors bet the process could provide cheap, clean energy. However, the technology is still under development, and experts have not yet given a time frame for its commercial success.

Several other fusion projects, including ITER in France, China’s Fusion Engineering test reactor and JT-60SA in Japan, use the “tokamak” design first developed by Soviet scientists in the 1950s. The device generates a donut-shaped cloud of plasma inside a chamber, held in place by powerful external magnets.

Mataira claims that in his reactor design he was able to “turn the tokamak design inside out.” Instead of external magnets, he used a levitating high-temperature superconducting magnet located inside a superheated plasma. The plasma is held inside a vacuum chamber within the magnetic field lines from north to south.

«The main engineering challenge is how to make a magnet surrounded by plasma work long enough,” Mataira said. Currently, the levitating magnet runs on a battery, which requires recharging after 80 minutes.

This reactor design was first developed by scientists at the Massachusetts Institute of Technology. According to Mataira, it scales better than tokamak reactors because it is easier to modify. “Building a tokamak is like building a ship in a bottle,” Mataira explained. “Every design decision made affects every other system.”

Dennis Whyte, a professor at the Massachusetts Institute of Technology and co-founder of US fusion company Commonwealth Fusion Systems, said he was “thrilled” with the reactor OpenStar built. In his opinion, “this adds an exciting opportunity to the variety of approaches to fusion.”

The head of OpenStar expects that nuclear fusion could become a commercial technology within six years. “We are enthusiastic about fusion because it can help decarbonize the energy sector, and there is a huge time crunch for that,” Mataira said.

It is worth noting that back in 1987, New Zealand adopted a law creating a nuclear-free zone in its territorial sea, land and air spaces. There are no nuclear power plants in the country. However, Mataira argues that OpenStar’s research complies with the country’s radiation safety laws. He is confident that the public understands the difference between nuclear fission and nuclear fusion, which does not create radioactive waste.

To date, the startup is funded by local New Zealand investors, but plans to raise between $500 million and $1 billion in the first quarter of 2025.