The prospect of harnessing the power of stars has moved closer to reality after scientists set a new record for the amount of energy released during a sustained fusion reaction.
Researchers at the Joint European Torus (JET), a fusion experiment in Oxfordshire, generated 59 megajoules of heat – the equivalent of around 14 kilograms of TNT – in a five-second burst of fusion, doubling the previous record of 21.7 megajoules set in 1997 by the same institution.
The exploit announced on Wednesday follows more than two decades of testing and refinement at the Culham Center for Fusion Energy and has been hailed as a “major milestone” on fusion’s path to becoming a viable and sustainable low-carbon energy source.
“These historic results have taken us a big step forward in tackling one of the greatest scientific and engineering challenges of all,” said Professor Ian Chapman, chief executive of the UK Atomic Energy Authority. “It is clear that we need to make significant changes to address the effects of climate change, and fusion offers enormous potential.”
The donut-shaped JET is designed to contain plasmas, or highly ionized gases, which are heated to 150 million degrees Celsius, 10 times hotter than the center of the sun.
At such extreme temperatures, atomic nuclei can fuse together to form new elements and release large amounts of energy. The same fusion reactions power the sun, but at considerably lower temperatures because the stars have gravity to lend a hand.
Experiments at JET have focused on the feasibility of fusion with a fuel based on two isotopes of hydrogen known as deuterium and tritium, which combine to form helium gas. The latest results suggest so and provide crucial confirmation for Iter, a larger merger project under construction in the south of France. Iter is expected to start burning deuterium-tritium fuel in 2035 and eventually generate more heat than needed to maintain its high-temperature plasma.
The prospect of harnessing the power of stars has moved closer to reality after scientists set a new record for the amount of energy released during a sustained fusion reaction. #ClimateAction #NuclearFusion #JET
If all goes well with Iter, the next step is to build a European demonstration plant that produces more electricity than it consumes and is connected to the grid. The prospect of fusion energy is deeply attractive because it does not emit greenhouse gases and a kilogram of fusion fuel contains about 10 million times more energy than a kilogram of coal, oil or gas.
While deuterium is abundantly available in seawater, tritium is extremely rare and produced in nuclear reactors. Future fusion plants, including Iter, should make their own tritium fuel using high-energy neutrons, released when deuterium and tritium fuse, to split common lithium metal into tritium and helium.
Dr Mark Wenman, a lecturer in nuclear materials at Imperial College London, said that although the experiment only released fusion energy for five seconds, it proved that the fuel could be burned from sustainable way. “It’s been a while since they produced a record like this and it’s a major step on the road to proving that fusion is a viable and sustainable energy source for the future.
“Five seconds doesn’t sound like a lot, but if you can burn it for five seconds, you can probably hold it steady and burn it for several minutes, hours, or days, which is what you’ll need for a good fusion power plant. is proof of this concept that they have achieved,” he said.
Professor Ian Fells, Emeritus Professor of Energy Conversion at Newcastle University, said the record release of fusion energy was “a milestone” in fusion research.
“It is now up to engineers to translate this into carbon-free electricity and mitigate the problem of climate change,” he added.