With the announcement of a "major breakthrough", nuclear fusion harnesses the power of stars to generate infinite clean energy without hazardous waste .
The U.S. Department of Energy is planning to announce a "major scientific breakthrough" at Lawrence Livermore National Laboratory, one of several sites around the world where researchers are trying to exploit the possibility of harnessing fusion energy .
Since nuclear fusion is considered by some to be the energy source of the future, especially because it produces nogreenhouse gases, produces little waste, and poses no risk of a nuclear accident, the announcement, which is expected to be announced Tuesday, has sparked heated debate in the scientific community .
It also has the potential to someday accelerate the planet's transition away from fossil fuels, which are the main cause of climate change but have long struggled with daunting challenges.
Here's what nuclear fusion is and some of the difficulties of turning it into the cheap, carbon-free energy that scientists think it can be.
what is nuclear fusion?
look up and it's happening right above your head - nuclear fusion reactions that power the sun and other stars.
This reaction occurs when two light nuclei merge to form a heavier nucleus. Because the total mass of a single nucleus is less than the mass of the two original nuclei, the remaining mass is the energy released in the process.
In the case of the sun, its high temperature—millions of degrees Celsius—and the pressure exerted by its gravity cause atoms to fuse otherwise mutually repelling atoms.
"We have to find a way to isolate this extremely hot matter from anything that can cool it. That's the problem of containment," said Erik Lefebvre, project leader at the French Atomic Energy Commission.
Back in the 1930s, scientists understood how nuclear fusion works and tried to replicate the process on Earth. Current efforts focus on fusing a pair of hydrogen isotopes -- deuterium and tritium. This particular combination releases "significantly more energy than most fusion reactions " and requires less heat.
How much would this be worth? Fusion technology offers "essentially unlimited" fuel possibilities if it becomes commercially viable, said Daniel Kamen, a professor of energy and society at the University of California, Berkeley. The required elements are available in seawater.
It is also a process that does not produce radioactive waste from nuclear fission - the technology currently used in nuclear power plants.
"Controlling the energy sources of stars is the greatest technological challenge humanity has ever faced," tweeted physicist Arthur Turrell, author of "Star Makers."
how close is it to reality?
Lefebvre warned that "the road is still long" before "commercially viable industrial-scale demonstrations". Such a project would take another 20 or 30 years to complete, he said.
The scientific community hopes the technology will be a game-changer for global energy production. "It's a completely carbon-free energy source that generates very little waste and is inherently very safe," said
Lefebvre, adding that fusion could be "the future solution to the world's energy problems."
How do scientists try to do this?
One way scientists are trying to recreate nuclear fusion involves the so-called tokamak - a ring-shaped vacuum chamber that uses powerful magnets to convert fuel into a superheated plasma - at temperatures between 150 million and 300 million degrees Celsius Time - nuclear fusion may occur.
The Livermore lab used a different technique, in which researchers fired 192 laser beams at a small capsule filled with deuterium-tritium fuel. The lab reported that a test in August 2021 yielded 1.35 megajoules of fusion energy -- about 70 percent of the targeted energy. Several subsequent experiments showed declining results, the lab said, but the researchers said they found ways to improve the mass of the fuel tank and the symmetry of the laser.
"The most critical feature in moving fusion from theory to commercial reality is that more energy is coming out than going in," Kammen said.
To achieve this goal, the researchers must first increase the efficiency of the laser and reproduce the experiment more frequently.