Washington (AFP)

A US public laboratory on Tuesday welcomed a "historic breakthrough" after having produced through nuclear fusion more energy than ever before, causing the enthusiasm of many scientists around the world.

The experiment, which took place Aug. 8 at the National Ignition Facility (NIF) in Calif., "Was enabled by the concentration of laser light," no less than 192, "on a target the size of a lead "of hunting, explains a press release.

This had the effect of "producing a hot spot the diameter of a hair, generating over 10 quadrillion watts by melting, for 100 trillionths of a second."

This is eight times more energy than during the last experiments carried out in the spring.

Nuclear fusion is considered by its supporters as the energy of tomorrow, in particular because it produces little waste and no greenhouse gases.

It differs from fission, a technique currently used in nuclear power plants, which consists in breaking the bonds of heavy atomic nuclei to recover energy.

Fusion is the reverse process: we "marry" two light atomic nuclei to create a heavy one.

In this case two isotopes (atomic variants) of hydrogen, giving rise to helium.

It is this process that is at work in the stars, including our Sun.

"This breakthrough places the researchers very close to the ignition threshold", according to the press release, that is to say the moment when the energy produced exceeds that used to cause the reaction.

Preparations are already underway to reproduce this experiment, which will take "several months", informs the press release, which specifies that detailed data will be published in a scientific journal.

"This result is a historic breakthrough for inertial confinement fusion research," said Kim Budil, director of the Lawrence Livermore National Laboratory, on which the NIF depends.

"The NIF teams have done an extraordinary job," commented Professor Steven Rose, co-director of the center for research in this area at Imperial College London.

"This is the most significant advance in inertial fusion since its inception in 1972."

"Transforming this concept into a source of renewable electrical energy will probably be a long process and will involve overcoming significant technical challenges", however tempered Jeremy Chittenden, co-director of the same center in London.

In France, the international Iter project also aims to control the production of energy from the fusion of hydrogen.

Reactor assembly began a year ago in Bouches-du-Rhône.

© 2021 AFP