John Jett & Jake Long/Lawrence Livermore National Laboratory/Reuters
US government scientists have achieved the second net energy gain in a nuclear fusion reaction. The results will add to the optimism that we are moving towards the dream of infinite carbon-free electricity.
Physicists have been trying to harness nuclear fusion reactions to power the sun since the 1950s, but until December, none of the research groups had been able to produce more energy than the reactions consumed. This reaction is also called ignition.
According to three people familiar with the preliminary results, researchers at Lawrence Livermore National Laboratory in California, who succeeded in igniting the fire for the first time last year, repeated the groundbreaking results in the experiment on July 30. Produces high energy output. .
The institute confirmed that the increase in energy was achieved again at the laser facility, adding that analysis of the results was underway.
“Since the first demonstration of fusion ignition at the National Ignition Facility in December 2022, we have continued our experiments to study this exciting new scientific regime. Conducted July 30. In the experiment, the NIF was repeatedly ignited.” “As is our standard practice, we plan to report those results at future academic conferences and in peer-reviewed publications.”
Nuclear fusion is accomplished by heating two hydrogen isotopes (usually deuterium and tritium) to such extreme temperatures that the nuclei fuse, releasing vast amounts of energy in the form of helium and neutrons.
While many scientists believe fusion power plants are still decades away, it’s hard to ignore the potential of this technology. Fusion reactions do not emit carbon and produce no long-lived radioactive waste. In theory, a cup of hydrogen fuel could power a home for hundreds of years.
The most widely studied approach, known as magnetic confinement, uses giant magnets to hold the fuel in place while it is heated to temperatures higher than the sun.
NIF uses a different process called inertial confinement, in which the world’s largest laser is fired into a small capsule of fuel to cause implosion.
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U.S. Energy Secretary Jennifer Granholm called the ignition achievement “one of the most impressive scientific feats of the 21st century” in December. In this experiment, the reaction produced about 3.15 megajoules, which was about 150% of his 2.05 MJ for the laser.
Early data from the July experiment showed an energy output of more than 3.5 MJ, two people with knowledge of the preliminary results said. This energy is enough to power a household iron for one hour.
Achieving a net energy gain has been considered for decades as an important step towards proving the feasibility of commercial fusion power plants. However, there are still some hurdles to overcome.
Energy gain in this context compares only the energy produced with the energy of the laser, not the total amount of energy drawn from the grid to power the system. Scientists estimate that commercial fusion would require reactions that produce 30 to 100 times the energy of lasers.
A NIF will do a maximum of one shot per day, whereas a confined power plant would probably need to complete several shots per second.
But one of the people with knowledge of the NIF’s results said the NIF’s improved results “only eight months” after the initial breakthrough were further signs of an increasing pace of progress.
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