US scientists confirm ‘major breakthrough’ in nuclear fusion energy

14 Dec 2022

The inside of an NIF preamplifier support structure. Image: Damien Jemison

For the first time, researchers were able to produce more energy from a fusion reaction than was used to trigger it – a massive step in the pursuit of clean, efficient energy.

Researchers have confirmed a “major scientific breakthrough” in nuclear fusion, giving hope for an abundant clean energy source in the future.

Scientists at the US National Ignition Facility (NIF) said they were able to produce a net energy gain from their latest fusion experiment.

This means they were able to produce more energy from the reactor than was used to trigger the reaction, which is a landmark step in the pursuit of clean energy.

Nuclear fusion – like the reactions that power stars such as our sun – brings together atoms of light elements like hydrogen at high temperatures to form helium and release tremendous energy as heat. Importantly, the process does not produce greenhouse gas emissions.

It is safer than nuclear fission – which involves the splitting of atoms – but has proven far more difficult to achieve. More than 60 years of research has gone into the possibility of fusion energy across the world.

The US researchers said they surpassed the fusion threshold by delivering 2.05 megajoules of energy into a small gold cylinder called a hohlraum, using 192 lasers.

The experiment resulted in 3.15 megajoules of energy output. The team said this demonstrated for the first time “a most fundamental science basis for inertial fusion energy”.

A key-shaped object with dimples across the surface and a green outline. It is an object used in nuclear fusion experiments.

NIF’s 192 lasers focus on a tiny fuel capsule suspended inside a cylindrical x-ray oven called a hohlraum (left, in the circle). The dimpled surface scatters stray light to prevent damage to the laser. Image: Jason Laurea

US secretary of energy Jennifer M Granholm said the work of scientists like those at NIF will help solve humanity’s “most complex and pressing problems”, such as providing clean power to tackle the climate crisis.

“This is a landmark achievement for the researchers and staff at the National Ignition Facility who have dedicated their careers to seeing fusion ignition become a reality, and this milestone will undoubtedly spark even more discovery,” Granholm added.

While the result is a breakthrough in the lab, the NIF team said more advanced science and technology developments are needed to achieve simple, affordable fusion energy that can power homes and businesses.

Other research teams around the world are working on advancing nuclear fusion technology. In February, UK scientists claimed to hit a new milestone of sustained fusion energy using the Joint European Torus tokamak.

In 2020, a fusion device in South Korea made a breakthrough when it maintained a temperature nearly seven times hotter than the sun for 20 seconds.

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Leigh Mc Gowran is a journalist with Silicon Republic