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Scientists make breakthrough with nuclear fusion record

February 10, 2022

European researchers have leaped closer to making nuclear fusion a practical energy source for humanity. It's the same power-generating process that makes stars, including our own sun, shine.

The donut-shaped tokamak in Culham, England, where high temperatures were generated to set the latest record
The donut-shaped tokamak in Culham, England, where the plasma mix was heated to set the latest recordImage: EFDA JET/dpa/picture alliance

Scientists announced progress on Wednesday in the mission to make nuclear fusion a safe, practical, and clean energy source — smashing the record for the amount of nuclear fusion energy produced.

The experiment at the Joint European Torus (JET) facility near Oxford, England, set a record of generating 59 megajoules of sustained fusion energy in a five-second period — well over double the previous amount.

What is nuclear fusion?

The fusion process is a reverse of what happens in existing nuclear power plants — nuclear fission — where energy is released when large atoms are broken down into smaller ones.

Nuclear fusion comes from bashing together two small atomic nuclei at such high temperatures that they fuse — and release energy.

The nuclei would normally repel one another, so unimaginably high temperatures are needed to make them move quickly enough to actually collide.

It's the same basic process that sees hydrogen in the sun converted into helium, generating sunlight and making life on Earth possible.

Fusion offers the prospect of climate-friendly, abundant energy without pollution, radioactive waste.

What did the scientists do?

In the experiment, the scientists heated tiny amounts of deuterium and tritium — two forms of hydrogen gas — to temperatures 10 times hotter than the center of the sun.

The superheated plasma can't be held in a normal container, which would be destroyed by it. Instead, it's kept in place by powerful magnets inside a donut-shaped machine known as a tokamak.

There, as it spins around and fuses, the plasma releases enormous amounts of heat as nuclear material is converted into energy.

A tweet from the UK Atomic Energy Authority showed the record pulse of energy as it happened. 

While that sounds slightly terrifying, the process is fundamentally safe in that — because it is so difficult to start and keep going — it cannot start a runaway process.

In terms of fuel, deuterium can be found in seawater, and tritium can be produced from lithium as a byproduct of the whole process.

Per kilogram of material used, the process releases nearly four million times more energy than burning fossil fuel, with unreactive helium the only waste product.

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Why is the latest result important?

At present, generating the sort of temperatures needed for fusion means more energy needs to be put in than can ever be extracted.

The fact that so much more power has been generated this time around means scientists are measurably closer to making the process sustainable.

Ian Chapman, the head of the UK Atomic Energy Authority, described it as a landmark event that moves researchers "a huge step closer to conquering one of the biggest scientific and engineering challenges of them all."

"It is a reward for over 20 years of research and experiments with our partners from across Europe."

"It's clear we must make significant changes to address the effects of climate change, and fusion offers so much potential. We're building the knowledge and developing the new technology required to deliver a low-carbon, sustainable source of baseload energy that helps protect the planet for future generations. Our world needs fusion energy."

Where does it go from here?

Scientists say years of work are still needed, with the level of energy achieved so far only modest, but that the record shows they are headed in the right direction.

"The record, and more importantly the things we've learned about fusion under these conditions and how it fully confirms our predictions, show that we are on the right path to a future world of fusion energy," said Tony Donne, program director at the EUROfusion consortium of research institutes. "If we can maintain fusion for five seconds, we can do it for five minutes and then five hours as we scale up our operations in future machines."

A larger, more advanced version of JET is currently being built in southern France, called ITER, supported by seven members — China, the European Union, India, Japan, South Korea, Russia, and the United States.

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Edited by: Farah Bahgat

Richard Connor Reporting on stories from around the world, with a particular focus on Europe — especially Germany.