National Ignition Facility reports new energy record in nuclear fusion
End of 2022, researchers at the NIF succeeded in generating more energy with a fusion reaction than they put into it. Now there are new records.
The fusion facility at Lawrence Livermore National Laboratory
(Image: LLNL)
Two and a half years ago, the National Ignition Facility, a division of the US research facility Lawrence Livermore National Laboratory (LLNL), made headlines with an energy record in nuclear fusion. Recently, the researchers there have set two more records, as reported by various US media.
In the most recent experiments, the NIF team achieved an energy yield of 5.2 megajoules. Later, a source with knowledge of the experiment told the online magazine TechCrunch that as much as 8.6 megajoules were generated. The LLNL has confirmed the reports.
At the end of 2022, the NIF generated 3.15 megajoules. This experiment is considered an important milestone in fusion research: for the first time, more positive energy was released during a fusion reaction than was put in: the lasers shot 2.05 megajoules at the fuel, and the reaction delivered 3.15 megajoules. This triggered a veritable fusion hype.
Not yet commercially viable
However, the total energy input required for the experiment, such as for cooling systems, was much higher and far exceeded the yield. This is why it is not yet commercially viable. However, the results indicate that controlled nuclear fusion is possible.
The NIF relies on the principle of laser-based inertial confinement fusion. The fuel – the hydrogen isotopes deuterium and tritium – is enclosed in a capsule. This is placed in a vacuum chamber. Almost 200 lasers irradiate the fuel capsule simultaneously. In this way, the conditions for fusion are created in the shortest possible time. Because of the short time, the plasma holds together due to the inertia, eliminating the need to enclose it in a magnetic cage.
In addition to laser-based inertial confinement fusion, a second approach is being pursued: fusion by magnetic confinement. In this process, plasma at a temperature of 100 million degrees is held in a magnetic field cage in a torus-shaped reactor chamber. Only at such temperatures, it is possible to overcome the repulsion of two positively charged hydrogen atomic nuclei and fuse them into a helium nucleus.
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Numerous research institutions and start-ups around the world are working on further developing laser fusion and magnetic fusion so that they can be used commercially.
(wpl)
