A small UK company which is aiming to revolutionise power generation through cracking nuclear fusion has today come one step closer.

Oxford-based Tokamak Energy, which is backed by hedge fund Winton Group, has managed to heat plasma to more than 15m degrees Celsius – hotter than the centre of the sun.

Tokamak called the process a “significant milestone” in its plan to have cracked the production of energy from nuclear fusion – the reaction which powers stars – by 2025.

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“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 Tokamak’s chief executive Jonathan Carling.

“Our aim is to make fusion energy a commercial reality by 2030. We view the journey as a series of engineering challenges, raising additional investment on reaching each new milestone.”

Tokamak achieved the new heat in a device called ST40, which was commissioned in 2017 and built by the firm itself. It is the third machine in a five-stage plan.

The firm received a new multi-million pound investment from Winton Group, the firm founded by David Harding, over the course of 2017.

It has so far received a total of £30m from investors who also include Oxford Instruments, Legal & General Capital and the Institution of Mechanical Engineers.

Tokamak’s technique involves “merging compression”, which releases energy as rings of plasma crash together and magnetic fields in the plasma reconfigure.

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This process, known as “magnetic reconnection”, is achieved by putting high electric currents through internal coils of the tokamak device – which requires power supplies to deliver thousands of amps in a matter of seconds.

Nuclear fusion, if achieved efficiently, would be a world-changing breakthrough in terms of renewable power generation. It needs minimal fuel, produces no greenhouse gases and no long-lived radioactive waste.

However so far, successful nuclear fusion has only been achieved by the world’s best scientists and has taken more energy than it has produced.

The next steps in stage three of Tokamak’s plan involve reaching fusion temperature of 100m degrees Celsius in the ST40, followed by further development of the machine to produce high density plasmas and to approach fusion energy gain conditions.