CNN
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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 results in a net increase in energy, sources familiar with the project have confirmed to CNN.
The U.S. Department of Energy is expected to formally announce the breakthrough on Tuesday.
The results of this experiment will be a major step in the decades-long quest to unlock limitless sources of clean energy that can help end our dependence on fossil fuels. For decades, researchers have tried to replicate nuclear fusion – replicating the nuclear fusion that powers the sun.
US Energy Secretary Jennifer Granholm is set to announce a “major scientific breakthrough” on Tuesday, the department said Sunday. The breakthrough was first reported by the Financial Times.
Nuclear fusion occurs when two or more atoms fuse into one larger atom. This is a process that produces a large amount of energy as heat. Unlike nuclear fission, which powers the world, it does not produce long-lived radioactive waste.
Scientists around the world are nudging towards breakthroughs, using different methods to achieve the same goal.
The National Ignition Facility project produces energy from nuclear fusion known as “thermonuclear inertial fusion.” In reality, US scientists fire pellets containing hydrogen fuel into an array of about 200 lasers, essentially a series of very fast, repeating explosions at a rate of 50 times per second.
Energy collected from neutrons and alpha particles is taken out as heat, and that heat holds the key to generating energy.
Tony Rollstone, a fusion expert at Cambridge University’s School of Engineering, told CNN: “They heat up on the outside. That creates a shock wave.”
The net increase in energy from fusion is a big deal, but it’s happening on a much smaller scale than the amount needed to heat the power grid or buildings.
Jeremy Chittenden, co-director of the Center for Inertial Fusion Research at Imperial College London, said: “To turn it into a power plant, we need more energy. We need to increase it significantly.”
In the UK, scientists are using giant donut-shaped machines equipped with giant magnets called tokamak to produce the same result.
The lost mass is converted into a huge amount of energy. The plasma must reach at least 150 million degrees Celsius, which is ten times the temperature of her in the core of the Sun. Neutrons that are able to escape the plasma hit the “blanket” that covers the tokamak walls and their kinetic energy is transferred as heat. This heat can be used to heat water, generate steam, or run turbines to generate electricity.
Last year, scientists working near Oxford were able to generate record amounts of sustained energy. Even then, it only lasted 5 seconds.
Whether you use a magnet or fire the pellets with a laser, the end result is the same. The heat maintained by the process of fusing atoms is key to helping produce energy.
A major challenge in harnessing fusion energy is sustaining it long enough to power grids and heating systems around the world.
Chittenden and Roulstone told CNN that scientists around the world must now work to dramatically scale up fusion projects and reduce costs. Many more years of research are needed before it becomes commercially viable.
“At the moment, we are spending an enormous amount of time and money on each experiment,” Chittenden said. “We need to cut costs significantly.”
Chittenden, however, called this new chapter in fusion a “tremendously exciting moment of real breakthrough.”
Roulstone said it shows that much more work is needed to make fusion power viable on a commercial scale.
“The counterargument is that this result is far from the actual increase in energy needed to generate electricity,” he said. It is far from providing useful energy.”