
A colossal laser system has created some of the most extreme conditions on Earth, bringing us one step closer to useful nuclear fusion power that would produce no hazardous waste. Researchers at Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) in California have been attempting to jump-start nuclear fusion in the laboratory for decades, and now they are closer than ever.
NIF works by focusing 192 of the world’s highest-energy lasers into a single powerful beam that shines on a small plastic sphere full of hydrogen. The intense heat makes the plastic explode, compressing the hydrogen inside. If the pressure is high enough, the hydrogen atoms will begin to fuse together, releasing a huge amount of energy.
On 8 August, NIF achieved its highest energy yield yet, putting out more than 1.3 megajoules of energy. That is 10 quadrillion watts of fusion power for 100 trillionths of a second. “That, in reality, is what it takes to boil a kettle,” at Imperial College London told the èƵ Weekly podcast. “So the amount of energy we would need to generate a power station would need to be hundreds or even thousands of times larger from every pulse.”
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Nevertheless, this yield is an improvement by a factor of eight over experiments conducted earlier this year, and puts NIF on the cusp of sparking fusion, the team said in .
“It’s literally held together for as long as it takes to explode,” said Chittenden. “What we’re trying to achieve is a plasma state very much similar to the centre of the sun… and we can’t hold that pressure together for very long.” The pressure of the hydrogen was orders of magnitude higher than what has previously been achieved in any laboratory, he said.
Not only is this a step towards clean nuclear power, it could also lead to physics experiments that help us understand the most extreme locations in the cosmos and the seconds after the big bang. Researchers at NIF are now planning the next round of experiments in the hope of reaching ignition.
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