Nuclear Fusion Breakthrough Confirmed: California Team Achieved Ignition. Research Continues
"A major breakthrough in nuclear fusion has been confirmed a year after it was achieved at a laboratory in California," reports Newsweek:Researchers at Lawrence Livermore National Laboratory's National Ignition Facility (NIF) recorded the first case of ignition on August 8, 2021, the results of which have now been published in three peer-reviewed papers.... Ignition during a fusion reaction essentially means that the reaction itself produced enough energy to be self-sustaining, which would be necessary in the use of fusion to generate electricity. If we could harness this reaction to generate electricity, it would be one of the most efficient and least polluting sources of energy possible. No fossil fuels would be required as the only fuel would be hydrogen, and the only by-product would be helium, which we use in industry and are actually in short supply of.... This landmark result comes after years of research and thousands of man hours dedicated to improving and perfecting the process: over 1,000 authors are included in the Physical Review Letters paper. This week the laboratory said that breakthrough now puts researchers "at the threshold of fusion gain and achieving scientific ignition," with the program's chief scientist calling it "a major scientific advance in fusion research, which establishes that fusion ignition in the lab is possible at the National Ignition Facility." More news from this week's announcement by the Lawrence Livermore National Laboratory:Since the experiment last August, the team has been executing a series of experiments to attempt to repeat the performance and to understand the experimental sensitivities in this new regime. "Many variables can impact each experiment," Kritcher said. "The 192 laser beams do not perform exactly the same from shot to shot, the quality of targets varies and the ice layer grows at differing roughness on each target...." While the repeat attempts have not reached the same level of fusion yield as the August 2021 experiment, all of them demonstrated capsule gain greater than unity with yields in the 430-700 kJ range, significantly higher than the previous highest yield of 170 kJ from February 2021. The data gained from these and other experiments are providing crucial clues as to what went right and what changes are needed in order to repeat that experiment and exceed its performance in the future. The team also is utilizing the experimental data to further understanding of the fundamental processes of fusion ignition and burn and to enhance simulation tools in support of stockpile stewardship. Looking ahead, the team is working to leverage the accumulated experimental data and simulations to move toward a more robust regime - further beyond the ignition cliff - where general trends found in this new experimental regime can be better separated from variability in targets and laser performance. Efforts to increase fusion performance and robustness are underway via improvements to the laser, improvements to the targets and modifications to the design that further improve energy delivery to the hotspot while maintaining or even increasing the hot-spot pressure. This includes improving the compression of the fusion fuel, increasing the amount of fuel and other avenues. "It is extremely exciting to have an 'existence proof' of ignition in the lab," said Omar Hurricane, chief scientist for the lab's inertial confinement fusion program. "We're operating in a regime that no researchers have accessed since the end of nuclear testing, and it's an incredible opportunity to expand our knowledge as we continue to make progress." Thanks to long-time Slashdot reader hesdeadjim99 for sharing the news.
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