China's 'artificial sun' reactor has switched on for the first time

A doughnut-shaped object in a building in China has blazed into life – and it will reach temperatures hotter than the sun.

The HL-2M Tokamak nuclear fusion reactor was turned on for the first time, scientists have announced.

Advocates for fusion power believe that the technology holds the promise of unlimited clean energy.

The HL-2M reactor is the most advanced nuclear fusion device in China and can reach temperatures of over 150 million degrees Celsius, according to the People’s Daily.

Watch: 13-year-old becomes youngest person to achieve nuclear fusion

That’s 10 times hotter than the sun’s core, and the reason it’s often referred to as an “artificial sun”, Science Alert reported.

The reactor went into operation on Friday and achieved its first plasma discharge, mimicking reactions that happen inside the sun.

Read more: Nuclear powered plane could fly from London to New York in three hours

Yang Qingwei, chief engineer of the HL-2M at the Southwestern Institute of Physics, told the People’s Daily: “The energy confinement time of international tokamak devices is less than one second.

“The shot discharge duration of the HL-2M is around 10 seconds, with an energy confinement time of a few hundred milliseconds.”

Tokamak reactors hope to generate fusion energy from a plasma trapped in a magnetic field – but the key to igniting the fusion of hydrogen atoms into helium atoms is temperature.

Read more: Mysterious “rogue planet” could be even weirder than we thought

Every nuclear reactor currently operating on Earth is a fission reactor – using energy released when heavy atoms such as uranium decay into smaller atoms, a process similar to the one used in the first nuclear weapons.

A fusion reactor works in the opposite way, harvesting the energy released when two smaller atoms join together, releasing tiny, fast-moving particles smaller than atoms.

But to do so, companies need to find a way to harvest energy from a plasma held at millions of degrees Celsius – something that has defied researchers for decades.

Last year, the British government said it would invest £220 million in the design of a nuclear fusion power station to enable a commercially viable plant to be constructed by 2040.

Supporters believe fusion could revolutionise energy production, as it does not release carbon emissions and is believed to be safe. But critics say commercially viable fusion remains at least 50 years in the future.

Downing Street said its investment would allow engineers and scientists to produce a conceptual design for the reactor, which will generate fusion energy and convert it into electricity.

The UK Atomic Energy Authority and partners from industry will work to complete the design by 2024 at the authority’s Culham Science Centre in Oxfordshire, which is home to a European fusion research programme.

Watch: Pyramid-shaped high-rises in China could be the future of architecture