Nuclear fusion generates the light and heat of stars, and scientists look to it to become our future sustainable energy source here on Earth. Now, a team of scientists at the National Ignition Facility at Lawrence Livermore National Laboratory in California (USA) have managed to cause a fusion reaction that lasted briefly; a very important achievement, because fusion requires such high temperatures and pressures that it easily vanishes. They did it with 192 lasers and temperatures more than three times hotter than the center of the Sun.
One more step towards near-pollution-free fusion power
The ultimate goal, which is still a few years away, is to generate power in the same way that the Sun generates heat, by packing hydrogen atoms so close together that they combine into helium, which releases torrents of energy.
The researchers used the world’s most energetic laser at the laboratory’s National Ignition Facility (NIF) to heat an isotope of hydrogen to many times the temperature in the Sun’s core . This created the pressure needed to trigger the fusion process in the hydrogen, which then heated the material on its own by a significant fraction of a megajoule without the help of other heat sources.
The scientists made some adjustments to the setup that included increasing the amount of laser energy focused on the fuel, while changing the geometry of the target and the way energy is transferred between laser beams. The result was a new way to control the implosion process that compresses and heats the fuel, allowing the creation of self-heating plasma.
With those results, along with preliminary results announced last August, scientists say they are on the verge of an even bigger breakthrough: ignition, the point at which fuel can continue to “burn” on its own and produce more energy. than is needed to cause the initial reaction.
” We’re very close to the next step,” said the study’s lead author, Alex Zylstra, an experimental physicist at Livermore.
Referencia: A. B. Zylstra et al, Burning plasma achieved in inertial fusion, Nature (2022). DOI: 10.1038/s41586-021-04281-w