For the first time, US scientists at the National Ignition Facility at Lawrence Livermore National Laboratory in California have successfully produced a nuclear fusion reaction that resulted in a net energy gain, a source familiar with the project confirmed to CNN.
The US Department of Energy is expected to officially announce the breakthrough on Tuesday.
The test’s outcome will be a major step forward in the decades-long quest to unleash an infinite supply of clean energy that could help end our dependence on fossil fuels. For decades researchers have tried to recreate nuclear fusion—the kind of fusion that powers the Sun.
U.S. Energy Secretary Jennifer Granholm will make an announcement on Tuesday about a “major scientific breakthrough,” the department announced Sunday. The breakthrough was first reported Financial Times.
Nuclear fusion Occurs when two or more atoms are fused together to form a large mass of energy as heat. Unlike nuclear fission, which powers electricity around the world, it produces no long-lasting radioactive waste.
Scientists around the world are making progress using different methods to achieve the same goal.
The National Ignition Facility program generates energy through nuclear fusion, known as “thermonuclear inertial fusion”. In practice, American scientists fire a hydrogen-fueled particle into an array of nearly 200 lasers, essentially producing very fast, repetitive bursts at a rate of 50 times per second.
The energy collected from neutrons and alpha particles is extracted as heat, and that heat holds the key to producing energy.
Tony Rolstone, a fusion expert at the University of Cambridge’s engineering department, told CNN: “They have a fusion reaction by bombarding the outside with light rays. “They heat the outside; it creates a shock wave.”
While the net energy gain from nuclear fusion is a big deal, it is much smaller than what is needed to heat power grids and buildings.
“It’s about what it takes to boil 10 kettles of water,” said Jeremy Chittenden, co-director of the Center for Passive Fusion Research at Imperial College London. “To turn that into a power plant, we’d have to make a huge gain in energy — it’d have to be significantly higher.”
In England, scientists are trying to create the same result with a giant donut-shaped machine with giant magnets called a tokamak.
After a small amount of fuel is injected into the tokamak, giant magnets are activated to generate plasma. The plasma must reach at least 150 million degrees Celsius, 10 times hotter than the core of the Sun. It binds particles from the fuel together. In nuclear fusion, the fused product has less mass than the original atoms. The missing mass becomes a huge amount of energy.
Neutrons that escape the plasma then strike a “blanket” on the walls of the tokamak, and their kinetic energy is converted into heat. This heat can be used to heat water, generate steam and power turbines.
Last year, scientists working near Oxford managed to generate record levels of sustained energy. However, it only lasted for 5 seconds.
Whether it uses magnets or fires particles with lasers, the result is the same: heat holds the key to producing energy through the process of binding atoms together.
A major challenge in harnessing fusion energy is sustaining it long enough to power power grids and heating systems around the world.
Chittenden and Rulestone told CNN that scientists around the world now need to dramatically scale up their fusion programs and cut costs. It will take years of more research to make it commercially viable.
“At the moment we spend a lot of time and money on every test we do,” Chittenden said. “We need to reduce costs by a huge factor.”
Still, Chittenden called this new chapter in nuclear fusion “a real breakthrough moment.”
Rulestone said there is still a lot of work to be done to develop fusion to produce electricity on a commercial scale.
“The counterargument is that this result is miles away from the actual energy gain needed to generate electricity,” he said. “Therefore, we can say that it is a victory for science, but it is far from providing useful energy.”