NUCLEAR FUSION MILESTONE REPEATED
San Diego’s General Atomics assists with ‘net energy’ experiment
About eight months after the Lawrence Livermore National Laboratory created “net energy” in a nuclear fusion experiment for the first time, researchers at the Northern California lab have repeated the feat — and with better results.
Some 192 high-powered lasers zeroed in on a diamond-coated target about the size of a peppercorn at the lab’s National Ignition Facility on July 30, creating a reaction that resulted in a greater amount of energy coming out than the amount of energy put in, hence the net gain.
San Diego-based General Atomics assisted in the experiment by making the target capsule and its assemblies.
Physics Today magazine, from
the American Institute of Physics, cited three sources who preferred not to be identified who said the July laser shot deposited 2.05 megajoules onto the target, yielding
3.88 megajoules of energy, with an uncertainty of 0.31 megajoules.
That’s about a 20 percent increase from the December shot, which produced 3.15 megajoules.
Lawrence Livermore officials have been reticent to reveal many details but have confirmed the July experiment came back with improved results.
“As is our standard practice, we plan on reporting these results at upcoming scientific conferences and in peer-reviewed publications,” the lab said in a statement.
If the results first reported by the Financial Times hold up, the successful repeat gives further encouragement to scientists who hope nuclear fusion can someday provide the world with a source of energy that can be vast, clean and practical.
“Achieving ignition was one of the great scientific achievements of our time,” Anantha Krishnan, senior vice president for the Energy Group at General Atomics, said in an email. “Repeating ignition just months later shows just how fast fusion research is progressing.”
Nuclear fusion differs from nuclear fission, which is the process
used in nuclear power plants such as the now-shuttered San Onofre Nuclear Generating Station. Fission splits the nuclei of atoms to create power while fusion causes hydrogen nuclei to collide and fuse into helium atoms that release incredible amounts of energy — essentially replicating the power of the sun.
In theory, fusion could generate virtually limitless amounts of carbon-free electricity without producing long-lived nuclear waste or running the risk of a meltdown. But even though scientists have tried to harness fusion’s energy potential since the 1950s, no commercial facilities exist.
Two competing fusion designs have developed over time.
The Livermore experiments use high-intensity lasers that trigger a series of reactions that slam atoms together many times per second. The other employs powerful electromagnets that confine fuel in the form of a plasma inside a doughnut-shaped metal vacuum chamber called a tokamak at incredibly high temperatures.
General Atomics is also deeply involved in developing magnetic fusion.
Working in conjunction with the federal government, the company operates the DIII-D National Fusion Facility, which houses the largest tokamak in the United States.
In a separate project involving magnets, General Atomics is fabricating and shipping key pieces that will be inserted into the ITER facility, an ambitious international project under construction in France.
News of the Livermore experiment in July “demonstrates the importance of public investment in fusion science and robust collaboration with the private sector,” General Atomics vice president of Inertial Fusion Technologies Mike Farrell said in an email.
The Biden administration has set a goal to deliver pilot-scale fusion within a decade, and earlier this year the U.S. Department of Energy
awarded $46 million to eight companies developing designs and research for fusion power plants.
But fusion has its share of skeptics.
There’s a long-running
joke that fusion is always 30 years away and critics worry that the time and money spent on research into an unproven technology could be better deployed on other clean-energy projects.
While the July experiment at Lawrence Livermore was a success, the Financial Times story noted the net energy gain “only compares the energy generated to the energy in the lasers, not to the total amount of energy pulled off the grid to power the system, which is much higher. Scientists estimate that commercial fusion will require reactions that generate 30 to 100 times the energy in the lasers.”
An article published in June in Scientific American reported on delays and cost overruns at ITER.
The project, the story said, was originally expected to be completed by 2016 but has been pushed back to at least 2025 while cost estimates have risen from $6.3 billion to more than $22 billion and documents “recently obtained via a lawsuit, however, imply that these figures are woefully outdated.”
But increasing numbers of private companies — some backed by billionaires such as Jeff Bezos and Bill Gates — are jumping into the fusion race.
The Fusion Industry Association recently counted 43 companies in the sector worldwide, attracting more than $6 billion in investments.