Ars writes Big leap for fusion: more energy produced than spent igniting fuel "Researchers in the US have overcome a key barrier to making nuclear fusion reactors a reality. In results published in Nature, scientists have shown that they can now produce more energy than put into igniting fuel, at least on an experimental scale. The use of fusion as a source of energy remains a long way off, but the latest development is an important step toward that goal."
"During the fusion process, smaller atoms fuse into larger ones, releasing huge amounts of energy. To achieve this on Earth, scientists have to create conditions similar to those at the center of the Sun, which involves creating very high pressures and temperatures. There are two ways to achieve this: one uses lasers and is called inertial confinement fusion (ICF), another deploys magnets and is called magnetic confinement fusion (MCF). Omar Hurricane and colleagues at the Lawrence Livermore National Laboratory opted for ICF, with the help of 192 high-energy lasers at the National Ignition Facility in the US, which was designed specifically to boost fusion research."
A capsule lined with isotopes of Hydrogen "is placed inside a gold cylinder, when the 192 lasers are fired, they hit the capsule and indirectly cause a fusion reaction. The lasers hit the gold container, which emit X-rays that heat the pellet and make it implode, causing a fusion reaction. According to Debbie Callahan, a co-author of the study: “When the lasers are fired, the capsule is compressed 35 times. That is like compressing a basketball to the size of a pea.” The compression produces immense pressure and temperature, leading to a fusion reaction. Problems with the process were overcome last September, when, for the first time, Hurricane was able to produce more energy output from a fusion reaction than the lasers put into it. Since then, he has been able to repeat the experiment."