Since its first experimental demonstration in 1958, the nuclear fusion remained out of reach as a reliable source of energy. For everything: from spacecraft to power plants. Because? The nuclear fusion reaction is difficult to do because it is difficult to control. Most of all, it is difficult to confine plasma (the ionized gas that reaches 100 million degrees Celsius).
Scientists worked extensively to improve the confinement of the plasma and thus the nuclear fusion reaction. Two main methods are the magnetic confinement and inertial confinement. And the latter finally managed to produce a self-sustaining nuclear reaction.
Nuclear fusion reaction, a milestone
For the first time, a fusion reaction achieved a record energy output of 1,3 megajoules and exceeded the energy absorbed by the fuel used to ignite it. Yes, there is still a long way to go, but the result is a huge improvement: 8 times greater than a few months before and 25 times greater than in 2018.
Physicists from the National Ignition Facility at Lawrence Livermore National Laboratory they are about to publish their results.
"This result is an important step in research into how to create a fusion reaction. It opens up a new way to explore and improve our homeland security missions. The team that made this possible has worked hard for many years," says Kim Budil , director of the Lawrence Livermore National Laboratory.
Inertial confinement fusion: a star is born
It all begins with a fuel capsule, made up of deuterium and tritium, isotopes heavier than hydrogen. This fuel capsule is then placed in a hollow gold chamber the size of an eraser - technically it's called hohlraum.
At this point, 192 high-powered laser beams are "fired" at the hohlraum, where they are converted into X-rays. These X-rays implode the fuel capsule, heating and compressing it under conditions comparable to those of the center of a star. We are talking about temperatures above 100 million degrees Celsius (180 million Fahrenheit) and pressures above 100 billion Earth's atmospheres.
The reaction transforms the capsule into a tiny mass of plasma.
The goal of the reaction? Producing more energy than you put into it.
According to the team's measurements, the fuel capsule absorbed over five times less energy than that generated in the merger process.
It is the result of hard work on the experiment. Scientists made many changes, including the hohlraum design, new laser technology, and modifications to increase the capsule's implosion rate.
The team presented its findings to the 63rd Annual Meeting of the American Physical Society. He now plans to conduct follow-up experiments to see if they can replicate the result and study the process in more detail.
I don't know when humanity will be able to harness the energy of the nuclear fusion reaction, but as far as this moment may be, today it is a little closer.