Fusion, a reachable dream

Fusion, a reachable dream

Although there are still years for commercial application, scientists have recently announced a milestone to develop the source of clean, safe and unlimited energy

  A group of researchers from the National Ignition Facility (NIF), belonging to the Lawrence Livermore National Laboratory (California, United States), announced a few weeks ago that, for the first time, it had achieved that a nuclear fusion process produced more energy than I had consumed. The work, published in Nature, supposed to reach one of the milestones considered key for the development of this promising type of clean energy.

  Spain has a nuclear fusion research program at the Center for Energy, Environmental and Technological Research (CIEMAT), where since 1998 they have been working with the TJ-II, an experimental fusion reactor for magnetic confinement. For Joaquín Sánchez Sanz, director of the National Fusion Laboratory, the finding of the NIF "was planned because it is a well-known development, there is no other in the world as well. The French are building the Mégajoule Laser, but all the others are experiments in magnetic confinement ", in contrast to the American, which works in a fusion for" inertial confinement ".

What this method proposes is to throw energy into a ball formed by a mixture of deuterium and tritium, two isotopes of hydrogen, forming a shock wave that causes a fusion of these two light atoms, which propagates outward, burning hydrogen. "We expected it to happen much more than what has happened. recognizes Sánchez Sanz. The objective of the NIF was to obtain what is called ignition with gain, that is, more energy than the lasers inject the ball of deuterium-tritium. In this result, warns the researcher, the energy required by the plant to operate the lasers is not counted. «In total, they have obtained 1% more of the energy they have put in, that is to say, very far from the expected goal, although it is an interesting result from the point of view of physics, since they have managed to get the process started. They have obtained the fusion of the center, but it has not spread abroad to burn everything. "

But there are other limitations. To get that spark, American researchers have had to design the experiment in a way that it is no longer compatible to burn everything. "They have put all the effort into generating the spark, even knowing that it was not going to spread," says Sánchez Sanz.

Goal 2050

«For Science, it is very interesting and, despite being its competitors, it makes us happy, although it is true that in magnetic confinement these quantities of energy were obtained many years ago, in the early 90s» with the experiments of the Joint European reactor Torus (JET), located near Oxford.

In 1997, this European reactor obtained a yield of 60%. However, the objectives of the International Thermonuclear Experimental Reactor (ITER), the ambitious project that is being built in Caradache (France) go much further. "Then we put 100 and we got 60. With the ITER we hope to get 50 and get 500," says the physicist. And he adds: "Another thing is if these 500 will last 5 minutes or 10. That will have to be fought, but we have a lot of confidence that we will get them."

The ITER project works with a horizon to obtain results around 2050. "It is necessary to understand that fusion is a transgenerational project," says Sánchez Sanz. But this search, although slow, is not fruitless. "It has advantages in the medium term, for example, for Spain, which thanks to programs such as ITER has won contracts to develop high technology," concludes the Spanish scientist.