British company successfully tested its prototype nuclear fusion reactor at temperatures hotter than the Sun

Representatives of a British firm claimed that its prototype nuclear fusion reactor has successfully sustained temperatures that exceed the heat generated by the Sun. In an article on SHTF, the company claimed that commercial customers could expect practical fusion power by 2030.

Tokamak Energy reported that its ST40 fusion reactor has managed to heat its plasma to temperatures of 27 million degrees Fahrenheit (15 million degrees Celsius). That is much hotter than the temperatures on the surface of the Sun, which measures almost 10,000 degrees Fahrenheit. It is around the same temperature as the Sun’s core, where the nuclear fusion process takes place.

“Reaching 15 million degrees is yet another indicator of the progress at Tokamak Energy and a further validation of our approach,” read the email statement of Jonathan Carling, the CEO of Tokamak Energy. “Our aim is to make fusion energy a commercial reality by 2030.”

The Oxfordshire-based company has built and operated several fusion reactors since 2009. Their third and current unit, the ST40, is one of the smallest such reactors in active service.

Like its fission counterpart, a fusion reactor is a large and complicated affair. They are at least as big as a house, with many being able to occupy entire football fields. In comparison, Tokamak Energy’s ST40 unit is around the size of a van.

“We are taking significant steps towards achieving fusion energy, doing so with the agility of a private venture, driven by the goal of achieving something that will have huge benefits worldwide,” said Carling in his email. (Related: A startup energy company claims to have created a stable fusion reactor that can supply the world with limitless energy.)

Spherical tokamak allows much higher temperatures in fusion reactors

Most fusion reactors follow one of two proven designs: the tokamak and the stellarator. Both methods trap very hot plasma matter within shaped magnetic fields.

Tokamak reactors are shaped like a donut. They employ a large electric current that twists the ionized matter into the right shape.

Stellarators are an earlier design for fusion reactors. They look like twisted versions of tokamaks but function in more or less the same way.

The ST40 is a spherical tokamak reactor. It is designed to make the hole in the middle of the plasma confinement area as small as possible. This leads to a more circular shape.

It uses high-temperature superconducting magnets to manage the plasma. According to Tokamak Energy, the compact size of a spherical unit allowed the ST40 to reach higher plasma pressures than donut-shaped tokamaks.

The company’s first prototype spherical tokamak was the ST25, which was built in 2013. A second unit followed in 2015.

For their third unit, the ST40, Tokamak Energy plans to reach temperatures of 180 million degrees Fahrenheit (100 million degrees Celsius.) This is nearly seven times the temperature recently achieved by the ST40.

The company plans to build a full-scale fusion reactor in 2025 that will be hooked up to the power grid by 2030.

The nuclear power of the sun and the stars

Whereas nuclear fission splits atomic nuclei to generate usable energy, nuclear fusion brings together two nuclei to produce energy. Fusion is a much cleaner process and has a far greater output, but it is also much more difficult to initiate and sustain as a power source.

Researchers and companies like Tokamak Energy have been working on practical nuclear fusion power for decades. In recent times, their efforts have begun to bear fruit. A number of prototype fusion reactors have managed to sustain hydrogen and helium plasma over increasingly longer amounts of time.

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