In the pursuit of clean, limitless, and zero-carbon power, physicists have achieved a remarkable milestone by attaining net energy gain in a fusion reaction for the second time. This breakthrough, achieved by US government scientists at the Lawrence Livermore National Laboratory in California, brings new hope for the practical realization of fusion energy.

Since the 1950s, scientists have been striving to harness the incredible power of nuclear fusion, which drives the Sun and stars. The ultimate goal has been to create a controlled fusion reaction that produces more energy than it consumes, commonly referred to as ignition. However, until December, no research group had managed to achieve this critical milestone.

Replicating the Breakthrough

The Lawrence Livermore National Laboratory first accomplished ignition in December 2022, marking a significant achievement. In a subsequent experiment conducted on July 30, the laboratory successfully replicated the breakthrough, surpassing the previous energy output. This positive outcome has energized the scientific community, and further analysis of the results is underway.

The Fascination of Fusion

Fusion is a process that involves heating two hydrogen isotopes, typically deuterium, and tritium, to extremely high temperatures. Under these extreme conditions, the atomic nuclei fuse, releasing vast amounts of energy in the form of neutrons and transforming into helium. The appeal of fusion lies in its clean and sustainable nature, as it emits no carbon and generates no long-lived radioactive waste.

Image: Ian Bott via FT

The Potential of Fusion Power

Despite the undeniable promise of fusion power, practical fusion energy stations are still projected to be decades away. Yet, the technology’s potential is too enticing to overlook. A small amount of hydrogen fuel, the basic building block of fusion, could theoretically power a household for hundreds of years. This highlights the immense energy potential of fusion and its positive impact on the environment.

Researchers have explored various approaches to achieving fusion, with two prominent methods being magnetic confinement and inertial confinement. The magnetic confinement approach uses powerful magnets to hold the fuel in place while it is heated to temperatures hotter than the Sun. On the other hand, the NIF employs inertial confinement, which involves firing the world’s largest laser at a tiny capsule of fuel, triggering an implosion and initiating the fusion reaction.

The successful achievement of ignition has garnered praise from US Energy Secretary Jennifer Granholm, who hailed it as “one of the most impressive science feats of the 21st century.” The December experiment produced approximately 3.15 megajoules (MJ) of energy, surpassing the 2.05 MJ from the lasers. In the recent July experiment, the initial data indicates an energy output greater than 3.5 MJ, equivalent to powering a household iron for an hour.

Clean energy that powers cars, homes, and even whole cities could be only decades away from being a reality.

Some Hurdles to Overcome

While the recent progress is encouraging, there are still substantial challenges ahead. Energy gain, as measured in the experiments, only compares the energy generated to the energy in the lasers, not accounting for the total energy required to power the fusion system. Scientists estimate that commercial fusion power stations will need to generate between 30 and 100 times the energy in the lasers.

A Step Towards the Future

The NIF’s maximum capacity of one shot per day also poses a limitation. To achieve practical fusion energy, an internal confinement power plant would likely require several shots per second. Despite these hurdles, the improved results at NIF within a mere eight months after the initial breakthrough signal a growing momentum in fusion research, giving hope for a cleaner and more sustainable future.

The recent achievement of net energy gain in fusion marks a significant milestone in the quest for clean and abundant energy. As researchers continue to push the boundaries of science, the dream of limitless fusion power draws closer to reality. The potential benefits of fusion are immense, offering a solution to our energy needs while preserving the environment. The journey toward commercial fusion power may be challenging, but the progress made so far proves that we are on the right path.

Filed in Green. Read more about and .