To create a nuclear fusion ignition, laser energy is converted into X-rays inside a hohlraum, which then compresses a fuel capsule until it implodes, creating a high-temperature plasma and at high pressure.
American researchers at the Lawrence Livermore National Laboratory (LLNL) in California have for the first time succeeded in producing a net energy gain by the nuclear fusion of two isotopes of hydrogen to form helium , producing an immense amount of energy in the process.
The United States Secretary of Energy, Jennifer Granholm, announced it on Tuesday in the company of LLNL scientists. She called the achievement historic, bringing the world closer to the possibility of creating abundant fusion energy without carbon.
It took generations of people to achieve this goal. It's a scientific milestone and it's also an engineering marvel, added engineer Arati Prabhakar, director of the White House Office of Science and Technology Policy.
Scientists have been trying for over 50 years to create energy through nuclear fusion, with the goal of making it a cleaner energy source .
It could one day allow humanity to break its dependence on fossil fuels, responsible for global warming. Another advantage is that it does not create radioactive waste, unlike nuclear fission.
Fusion is different from fission, a technique used in nuclear power plants today which involves breaking bonds heavy atomic nuclei to recover their energy.
A hohlraum is a laboratory device designed to produce radiation that perfectly absorbs all the electromagnetic energy it receives. This houses the type of cryogenic target used to achieve the December 5, 2022 breakthrough.
Net energy gain has long been an elusive goal as fusion produced at such high temperatures and pressures that it is incredibly difficult to control.
This nuclear reaction is what powers the stars, including our Sun. Thanks to the extreme heat and pressure conditions there, the hydrogen atoms fuse together to form helium, producing an immense amount of energy in the process.
On Earth, this process can be achieved using ultra-powerful lasers.
At LLNL, on December 5, no less than 192 lasers were aimed at a target as small as a thimble, in which was placed a tiny capsule made of diamond, and containing isotopes of the chemical. hydrogen (deuterium and tritium).
The lasers generated a temperature of about 100 million degrees Celsius, causing the hydrogen atoms to fuse together. The reaction takes only a tiny fraction of a second.
Scientists have thus produced about 3.15 megajoules of energy, originally delivering 2.05 megajoules via lasers, according to the release.
However, 300 megajoules of energy drawn from the power grid were required to activate the lasers – making the operation overall still loss-making. But according to scientists, it will eventually be possible to overcome this problem.
Our calculations suggest that it is possible with a large-scale laser system to achieve an output of several hundred megajoules, explained Kim Budil, director of the Lawrence Livermore National Laboratory. But we are still a long way off.
Industrial and commercial solutions that will enable the production of energy to power homes and businesses from nuclear fusion are therefore not for tomorrow , since the technological challenges remain significant.
I don't think we or our children or great-grandchildren will directly benefit from nuclear fusion, says Pierre-Olivier Pineau, holder of the Chair of Energy Sector Management at HEC Montréal
An opinion that nuclear reactor specialist Guy Marleau shares.
“Maybe in 2080…2090, but there may be other discoveries and other ways to initiate the fusion reactions that will appear by then. »
— Guy Marleau, Associate Professor at Polytechnique Montreal
Other nuclear fusion projects are in development, including the international ITER project , currently under construction in France.
Instead of lasers, the so-called magnetic confinement technique will be used: the hydrogen atoms will be heated in a huge reactor, where they will be confined using of the magnetic field of magnets.
With information from Associated Press, and Agence France-Presse