In August 2021, scientists at the Lawrence Livermore National Laboratory in Northern California announced that they had achieved this. A historic turning point Around Nuclear fusion by passive occlusionDifferent from the method used by magnetic blockage in Tokamak More research focus.
At the National Ignition Facility (NIF) they succeeded in creating a plasma emitting 1.3 megajoules (MJ) per nanosecond, the most powerful laser used to test American nuclear weapons. Tests.
The experiment assembles 192 high-powered laser beams focused on a microscopic capsule filled with hydrogen isotopes locked in a cylinder (made of reduced uranium and gold) at a distance of 300 m.
This display does not even last the eyelids: in a second, the molten plasma is brought to a temperature of 150 million degrees.
The 1.3 MJ output produced during this experiment is a record, but it is still far from the goal. It represents only 70% of the energy used to produce this plasma.
The goal is to eventually exceed the ignition limit, which happens when this percentage exceeds 100%. Plasma is then converted into energy.
Almost more than the sun
Direct scientific review This record was interested in the established conditions, so it was able to produce 13 million billion watts.
It is based on two articles published by researchers at the University of California, Berkeley, explaining that this success owes much to the precise arrangement of the capsule where the fusion took place and to its opaque and almost sealed gold vessel. And uranium (hohlraumTo close friends).
Despite the size of the capsule (not more than a millimeter in the wing) and the contraction of the reaction, the energy released is equal to 10% of the solar energy received by the Earth at any one time.
Such a result is explained by the principle of the chain reaction: the fusion process makes it possible for the plasma to get very hot, which is capable of inducing other fusion reactions.
Two studies published by LiveScience describe several months of work, focusing specifically on the form given to the capsule. It finally comes in the form of a spherical shell.
To represent it, we can imagine a fruit in the shape of a ball, from which we would have removed its stone in the form of a ball. This system allows NIF lasers to be more efficient as they enter the holster, and the heat dissipates much faster.
The fact that science is now able to obtain glowing plasma indicates a significant improvement, viewers explain. They believe that this improvement will not fail to allow others, which will lead to the ignition threshold.
For physicist Annie Gritser of the Lawrence Livermore National Laboratory, these giant steps may be instructive about other types of fusion. Tokamax.