Nuclear fusion, historic result: a reaction has produced more energy than needed to trigger it

The rumors had been circulating since yesterday, but recently we have all the details. What are we talking about? Of the scientific news of the dayi.e. the first time a controlled nuclear fusion gave back a net gain in energy. In a nutshell, at the laboratories of the Lawrence Livermore National Laboratory (LLNL), in California, it was possible to obtain for the first time more energy than necessary to trigger a fusion reaction.

Where current nuclear power plants release energy from the splitting of atoms in fission reactions, fusion reactors aim to produce energy in the same way the Sun does, by bringing the nuclei closer together to join together forming the nucleus of a new heavier chemical element. This way possible obtain clean energy (without significant waste) which, in the future, could allow us to say goodbye to fossil fuels.

L’experiment conduit on December 5th at the National Ignition Facility (NIF) of the LLNL based on the technology of the “laser confinement”, different from the magnetic one used in other controlled fusion experiments such as the European ITER. “We have had a theoretical understanding of fusion for over a century, but the journey from knowing to doing can be long and arduous. Today’s milestone shows what we can do with persistencesaid Dr. Arati Prabhakar, chief adviser to the president on science and technology and director of the White House Office of Science and Technology Policy.

They were useful 192 laser beams aimed at a tiny pellet of fuel (composed of tritium and deuterium) e 2.05 megajoules (MJ) of energy to trigger the fusion reaction, obtaining an output value of 3.15 megajoules.

More precisely, the lasers struck a small gold cylinder known as a hohlraum, which converts UV rays into X-rays. Suspended inside is a diamond-coated capsule the size of a peppercorn, containing two isotopes of hydrogen , deuterium and tritium, which the X-rays imploded, creating a high-temperature, high-pressure plasma that has compressed the fuel inside to the point where its nuclei have fusedthey released a huge amount of energy. Only 4% of the deuterium-tritium fuel burned in the fusion reaction, suggesting plenty of room for improvement.

An historic result, which will trigger new investments in the sector even private – and we will get closer to the farewell to fossil fuels. When? Hard to say, to be cautious we are talking about a first commercial power station in about 30-40 years. At the Lawrence Livermore National Laboratory they profess caution: “Many scientific and technological developments are still needed to obtain simple and inexpensive IFE (inertial fusion energy) to power homes and businesses.”

Yes, because if the result demonstrates that what is theorized is truly possible, and therefore of truly unprecedented importance, there are many aspects that must be addressed and resolved before making nuclear fusion the world’s energy. For example, useful to know that to get the lasers to the necessary power to produce the ignition energy needed draw 300 megajoules of power from the electricity grid.