Scientists have long dreamed of using nuclear fusion as a source of plentiful, clean energy. That vision came one step closer to reality Tuesday when physicists at the Lawrence Livermore National Laboratory in California achieved ignition: a stable fusion reaction that produces more energy than its input.
Walter Pettus, assistant professor of physics at IU, interned at Livermore in 2012 as part of his doctoral studies.
Pettus didn’t work with the National Ignition Facility that has produced the fusion reaction, but he said the team was attempting to reach ignition a decade ago. The facilities were state-of-the-art but still had to address numerous logistical hurdles.
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“The fact that the sun is working tells us absolutely that fusion as an energy source works,” Pettus explained. “But the devil is in the details, and the very extreme conditions that you need to have all of these materials at really easily breed instabilities.”
Nuclear fusion works by aiming powerful lasers at a tiny hydrogen target, condensing and heating it to extreme temperatures. Tuesday’s reaction lasted less than 100-trillionths of a second but produced as much energy as a pound of TNT.
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Pettus said that commercially viable fusion energy is still decades away. For one thing, ignition only considers the energy output from lasers, while the facility itself requires far more energy to function.
Nonetheless, he said the amount of progress researchers made in the past year can’t be overstated.
“They are a factor of 10 better in the yields than where we were, say, at the beginning of 2021,” Pettus said. “They're solving the right problems so that they can make a significant advance in really quite a short period of time.”
