The National Ignition Facility has, for the first time, generated more energy than it’s put in to a fusion reaction.
The most critical part of the reaction, and one that had been a real concern for Hurricane’s team, is the shape of the fuel capsule. The capsule is made from a polymer and is about 2mm in diameter (about the size of a pinhead). On the inside it is coated with deuterium and tritium—isotopes of hydrogen—that are frozen to be in a solid state.
This capsule is placed inside a gold cylinder, where the 192 lasers are fired, hitting the capsule and causing a fusion reaction. The lasers hit the gold container, which emit X-rays, which heat the pellet and make it implode instantly, 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 fuel put into it. Since then he has been able to repeat the experiment.
The article also explains the differences between inertial confinement fusion (ICF or lots of big damn lasers) and magnetic confinement fusion (MCF or lots of big damn magnets). With the amount of criticism heaped on Livermore Labs over it’s apparent failure to produce results, it’s good to see them get one for the win column.