Breakthrough in nuclear fusion, one step closer to society's benefits

National Ignition Facility & Photon Science (NIF)

An experiment, conducted on August 8, at the National Ignition Facility & Photon Science (NIF) in the United States has achieved a "historic" breakthrough by achieving a greater amount of energy from nuclear fusion than has ever been achieved before.

This facility occupying a ten-story building the size of three soccer fields used 192 laser beams focused into a small capsule, the size of a pellet and capable of storing a mixture of deuterium and tritium, heating it to 3.3 million degrees Kelvin. This had an effect that produced a hot spot the diameter of a hair, generating more than 10 trillion watts per fusion for 100 billionths of a second. This is eight times more energy than during the last experiments carried out previously.

Nuclear fusion consists of "joining" two light atomic nuclei to create a heavy one, in this case two isotopes of hydrogen and producing helium, generating little waste in the process and no greenhouse gases. This is the same thing that happens in stars, including the Sun.

This breakthrough has raised great optimism among scientists around the world as the ignition threshold, i.e. the point at which the energy produced exceeds the energy used to trigger the reaction, is considered to be close to being reached and there are plans to replicate the experiment in the coming months.

This experiment is not ITER

The International Thermonuclear Experimental Reactor (ITER) is an international project under construction in Cadareche (France), whose milestones have become known in recent months.

Its purpose is to fuse the deuterium and tritium nuclei contained in the fuel that powers a reactor to produce an enormous amount of energy. The by-product is ionized helium-4 and a high-energy neutron, which is the particle that will ultimately be used to produce electricity.

To make this possible, it is necessary to transform the energy contained in this neutron (about 14 MeV) into electrical energy through a process very similar to that used in today's fission nuclear power plants.

The difference between this new experiment and the ITER project is that the latter confines the gas containing the deuterium and tritium nuclei with a magnetic field and heats it up to 150 million degrees Celsius. At that temperature, the kinetic energy acquired is enough to overcome the repulsion of both nuclei (since both have a positive electric charge which makes them repel each other) and fuse.

However, there is another technology known as nuclear fusion by inertial confinement, which has been used by NIF. This consists of using a very small amount of fuel, in the form of a small ball of deuterium and tritium, and making it implode by suddenly concentrating the energy of a large number of high-power lasers on it. The fuel condenses and the probability of the nuclei fusing is increased.

Source: NIF Experiment puts Researches at Thereshold of Fusion Ignition