For the first time ever, US scientists have successfully performed a nuclear fusion reaction that resulted in a net energy gain at Lawrence Livermore National Laboratory’s National Ignition Facility in California, a source familiar with the project confirmed to CNN.
The US Department of Energy is expected to officially announce the breakthrough on Tuesday.
The result of the experiment is a giant step in a decades-long quest to unlock an infinite source of clean energy that could help end dependence on fossil fuels. For decades, researchers have tried to replicate nuclear fusion – a replica of the fusion that powers the sun.
US Energy Secretary Jennifer Granholm will make an announcement on Tuesday about a “major scientific breakthrough,” the department said on Sunday. The breakthrough was first reported by the Financial Times.
Nuclear fusion occurs when two or more atoms fuse into one larger one, a process that produces a tremendous amount of energy in the form of heat.
Scientists around the world are nearing the breakthrough; In February, British scientists announced they had more than doubled the previous record for generating and sustaining nuclear fusion.
Scientists working near Oxford have been able to generate a record-breaking amount of sustainable energy in a giant donut-shaped machine called a tokamak, equipped with giant magnets. Still, it only lasted 5 seconds.
The heat generated by the process of atom fusion is key to supporting energy production.
As CNN reported earlier this year, the fusion process produces helium and neutrons – which have a lower mass than the parts from which they were originally made.
The missing mass is then converted into an enormous amount of energy. The neutrons, which are able to escape the plasma, then hit a “blanket” lining the walls of the tokamak, and their kinetic energy is transferred as heat. This heat can then be used to heat water, produce steam, and drive turbines to generate electricity.
The machine that produces the reaction must be exposed to intense heat. The plasma must reach at least 150 million degrees Celsius, ten times hotter than the core of the sun.
The major challenge in harnessing fusion energy is sustaining it long enough for it to power grids and heating systems around the world.
A British fusion scientist told CNN that the result of the US breakthrough is promising, but also shows that more needs to be done for fusion to generate power on a commercial scale.
“They worked on the design and the composition of the target and the shape of the energy pulse to get much better results,” Tony Roulstone of the University of Cambridge’s Department of Engineering told CNN.
“The counter-argument is that this result is miles away from the actual energy harvesting needed to generate electricity. Hence we can say that (it) is a success of science, but far from providing useful energy.”