2nd nuclear fusion breakthrough brings us a (tiny) step closer to limitless clean energy - Livescience.com
2nd nuclear fusion breakthrough brings us a (tiny) step closer to limitless clean energy | Live Science
2nd nuclear fusion breakthrough brings us a (tiny) step closer to limitless clean energy
News Ben Turner
The breakthrough marks the second time that the core of a fusion reactor has given out more energy than it has taken in, but significant challenges remain.
A nuclear fusion reaction that puts in more energy than it gives out has been demonstrated by U.S. scientists for a second time. The successful experiment takes us one small but meaningful step closer to creating a new source of limitless clean energy.
By firing the world's most energetic laser beam to briefly transform a pellet of hydrogen isotopes into a fiery plasma, the physicists produced a higher net-energy gain than they did on their first attempt last year.
"Since demonstrating fusion ignition for the first time at the National Ignition Facility in December 2022, we have continued to perform experiments to study this exciting new scientific regime. In an experiment conducted on July 30, we repeated ignition at NIF," the researchers said in an emailed statement. "As is our standard practice, we plan on reporting those results at upcoming scientific conferences and in peer-reviewed publications."
Related: Fusion power key to Earth's survival, says Bill Nye in exclusive interview
Scientists have been trying to find practical methods to create nuclear fusion— the process that makes stars like our sun burn — since the 1940s. Stars fuse hydrogen atoms to make helium under extremely high temperatures and pressures, converting matter into light and heat and producing energy — without also creating damaging byproducts such as greenhouse gases or radioactive waste.
Recreating these conditions on Earth, however, is far from simple. Besides hellish temperatures and immense pressures, vast amounts of energy are needed to transform fuel into a plasma, ignite it and safely corral it with powerful magnetic fields or laser beams.
This feat has so far, only been demonstrated by the NIF, at the Lawrence Livermore National Laboratory in California. And the NIF only did so in an experiment that sputtered out in less than ten billionths of a second.
Two types of reactors dominate current fusion experiments: magnetic confinement reactors, which steer heated plasma with magnetic fields; and inertial confinement reactors like the one at the NIF. The NIF’s experiment streamed photons, or light particles, into two ends of a cylinder inside the reactor's core to strike the inner walls of a gold capsule containing tritium and deuterium, producing X-rays that heated the fuel pellet.
This sparked a reaction that created more energy than the lasers put in (in the first experiment, roughly 3.15 megajoules output for the 2.05MJ input). However, neither experiment produced more energy than the enormous amount expended to power the whole reactor, with the reaction beginning and ending in a tiny fraction of a second.
Scientists have warned that getting more energy out from the entire reactor than was put in could take several decades, so advancements likely won’t arrive in time to help humanity fight climate change. These experiments do, however, provide compelling evidence that the power of stars could one day be used to power human life on Earth.
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Ben Turner is a U.K. based staff writer at Live Science. He covers physics and astronomy, among other topics like tech and climate change. He graduated from University College London with a degree in particle physics before training as a journalist. When he's not writing, Ben enjoys reading literature, playing the guitar and embarrassing himself with chess.
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Nuclear energy provides almost 20 percent of the U.S. electricity supply. Advocates have called for an expanded role for nuclear as an emissions-free fuel source. But the economics of building new reactors are daunting. In addition, lingering safety concerns are an institutionalized part of the calculation of nuclear regulation, and highly radioactive nuclear waste remains a can that public officials have been inclined to kick down the road. The Energy Information Administration projects a sharp decline in nuclear power generation over the next decade, as new nuclear plants — two are planned — are more than offset by anticipated retirements of several operating reactors.