Scientists Successfully Replicate Historic Nuclear Fusion Breakthrough Three Times

After producing a nuclear fusion reaction last year that released more energy than it used, scientists at the National Ignition Facility at the Lawrence Livermore National Laboratory in California (LLNL) say they have successfully replicated the process at least three times this year. "This marks another significant step in what could one day be an important solution to the global climate crisis, driven primarily by the burning of fossil fuels," reports CNN. The announcement appears in a December report (PDF) from the LLNL. From the report: After making their historic net energy gain last year, the next important step was to prove the process could be replicated. Brian Appelbe, a research fellow from the Centre for Inertial Fusion Studies at Imperial College London, said the ability to replicate demonstrates the "robustness" of the process, showing it can be achieved even when conditions such as the laser or fuel pellet are varied. Each experiment also offers an opportunity to study the physics of ignition in detail, Appelbe told CNN. "This provides valuable information to the scientists in addressing the next challenge to be overcome: how to maximize the energy that can be obtained." There are different ways of creating energy from fusion, but at NIF, scientists fire an array of nearly 200 lasers at a pellet of hydrogen fuel inside a diamond capsule the size of a peppercorn, itself inside a gold cylinder. The lasers heat up the cylinder's outside, creating a series of very fast explosions, generating large amounts of energy collected as heat. The energy produced in December 2022 was small -- it took around 2 megajoules to power the reaction, which released a total of 3.15 megajoules, enough to boil around 10 kettles of water. But it was sufficient to make it a successful ignition and to prove that laser fusion could create energy. Since then, the scientists have done it several more times. On July 30, the NIF laser delivered a little over 2 megajoules to the target, which resulted in 3.88 megajoules of energy -- their highest yield achieved to date, according to the report. Two subsequent experiments in October also delivered net gains. "These results demonstrated NIF's ability to consistently produce fusion energy at multi-megajoule levels," the report said. There is still a very long way to go, however, until nuclear fusion reaches the scale needed to power electric grids and heating systems. The focus now is on building on the progress made and figuring out how to dramatically scale up fusion projects and significantly bring down costs.

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