The scientists of the Lawrence Livermore National Laboratory They already knew it was a matter of time. In August 2021, thanks to the most powerful laser ever conceived installed at the National Ignition Center (NIF), they already managed to ‘touch’ the dream of controlling fusion, the recreation of the energy of the stars that it is promised as a clean, sustainable and almost inexhaustible source. A year and a half later, the hope (and the huge investment) has come true: finally, they have managed to generate more energy with the reaction than it takes to activate it. A historical milestone applauded by the entire scientific community.
Specifically, 2.05 megajoules were required to ‘turn on’ the reactor, but 3.15 megajoules were generated, which would give a positive gain of more than 1 megajoule. The key, precisely, has been the NIF’s powerful laser, which is actually 192 beams pointing with a margin of error of just the thickness of a human hair at a tiny gold capsule, full of deuterium and tritium. Thanks to the enormous pressure exerted on this ‘ball’, the reaction was generated, which only lasted the blink of an eye, although long enough to show that the system works and that the extreme energy that ‘turns on’ the stars can be replicated here on Earth.
The experiment took place on December 5, so the researchers have stressed that there is still a long way to analyze the data before it is reviewed by independent experts and published in a scientific journal, which will open the way for other groups to scientists to deepen their research and that the system can continue to progress.
“This is just the beginning,” said the US Secretary of Energy. Jennifer Granholmin a long-awaited press conference with the director of the White House Science and Technology Policy, Arati Prabhakarand other government officials and scientists.
A great day for science
“It was a great day for science,” said the Undersecretary of the National Nuclear Security Administration (NNSA) during the appearance. Jill Hruby. “Achieving ignition in a controlled fusion experiment is an achievement that follows decades of global research development, engineering, and experimentation,” Hruby said.
In the 1960s, Livermoore scientists led by John Nuckolls They hypothesized that laser beams could be used to achieve fusion ignition: that is, to recreate the high temperatures and pressures found in the cores of stars. Thereafter they began to create a laser system that occupies a ten-story building the size of three football fields and took 12 years to complete as it stands today.
In search of the commercial fusion reactor
“Without a doubt, it is a very important scientific milestone, since it had never been possible to have a positive net gain,” he told ABC. Carlos Hidalgo, deputy general director of the National Fusion Laboratory of the Ciemat. «However, it is necessary to know that in order to apply it to a commercial reactor, science and technological development must be combined. And, for the moment, the inertial confinement on which the NIF model is based is not as advanced as others ».
The problem is precisely how to get the reaction: for each shot, each of the beams needs to be calibrated to the millimeter; not only that, it is also necessary that the sphere of deuterium and tritium be perfect -if not, the reactions are much weaker-. “To maintain a sustained reaction over time, we should shoot one pellet after another continuously, which right now is far from the necessary technological development,” says Hidalgo. Something like 10,000 spheres a day, which in the words of the experts, would mean unprofitable energy expenditure. In fact, having the camera ready for one shot a day is a technical achievement that took years to perfect.
This is something that the scientists responsible for the project do not hide. “There are still significant obstacles not only scientifically, but also technologically,” admitted Kim Budil, director of the laboratory. “There are still decades to get a commercial reactor.”
On the contrary, there are other systems, called tokamak models, in which although a positive net profit has not yet been achieved, scalable reactors are expected to be achieved. This is the goal ofITER project (acronym for International Thermonuclear Experimental Reactor, in which some thirty countries participate, including the US, all the nations of Europe and giants such as China or Russia, for now), which will build a pilot reactor in Cadarache (France) to prove that nuclear fusion plants are viable.
These devices are a kind of hollow ‘donut’ inside which a small amount of fuel made up of hydrogen, deuterium and tritium is injected, which is heated to high temperatures and becomes an ionized plasma that reaches 150 million degrees Celsius, the fusion taking place thanks to a gigantic and very powerful magnet that contains the reaction.
Although the inertial confinement model has advanced in achieving the milestone of ignition, Hidalgo points out that the magnetic confinement system is much more advanced in engineering, and that ITER will achieve much higher and sustained performance over time (that is, a continuous and reliable source) that will allow us to turn on household appliances with energy from the stars. However, we will have to wait at least until 2028 for their first experiments to begin.
Still, the entire scientific community agrees that the NIF has indeed just made a historic scientific breakthrough. A milestone that opens the door to research on extreme states of matter, to better understand what the energy that feeds our Sun is like. Also, according to what the NNSA deputy administrator for Defense Programs has stated, Marvin Adamsis an opportunity to help NNSA’s weapons deterrence programs, “without explosive nuclear testing.”