Energy

Nuclear fusion milestone creates "burning plasma" for the first time

Nuclear fusion milestone creat...
A key goal in nuclear fusion research is to achieve self-heating plasma, and scientists at the National Ignition Facility claim to have done just that in newly published research
A key goal in nuclear fusion research is to achieve self-heating plasma, and scientists at the National Ignition Facility claim to have done just that in newly published research
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A key goal in nuclear fusion research is to achieve self-heating plasma, and scientists at the National Ignition Facility claim to have done just that in newly published research
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A key goal in nuclear fusion research is to achieve self-heating plasma, and scientists at the National Ignition Facility claim to have done just that in newly published research

For the prospect of limitless, clean energy produced through nuclear fusion to become a reality, scientists need the reactions at the heart of the technology to become self-sustaining, and newly published research has edged them closer to that goal. Scientists using a high-powered laser at the National Ignition Facility in the US have achieved "burning plasma" for the first time, demonstrating for a fleeting moment how the fuel can provide much of the heat needed to keep the reactions going.

Scientists have been pursuing nuclear fusion technology at the National Ignition Facility since it came online in 2009, using 192 lasers housed inside a 10-story building to deliver 1.9 megajoules of ultraviolet energy onto a fuel capsule roughly the size of a ball bearing. This creates tremendous pressure and temperature that causes separate atoms to fuse into helium, a reaction that releases vast amount of energy.

This mimics the reactions that take place inside the Sun, but the trouble is creating them here on Earth requires huge amounts of energy to initiate the process. The overarching objective in this field is to have the fusion reactions become the primary source of heat instead, creating a self-sustaining form of nuclear fusion and ongoing energy production.

The results of experiments undertaken at the National Ignition Facility in November 2020 and February 2021 confirm small but critical steps toward this aim. The scientists made a few tweaks to the setup that included scaling up the amount of laser energy focused on the fuel, while changing the geometry of the target and the way energy is transferred between the laser beams. The result of this was a novel way to control the implosion process that compresses and heats the fuel, enabling the creation of self-heating plasma.

“In these experiments we achieved, for the first time in any fusion research facility, a burning plasma state where more fusion energy is emitted from the fuel than was required to initiate the fusion reactions, or the amount of work done on the fuel,” said lead author Annie Kritcher.

Though the lifetime of the plasma was measured in just nanoseconds, the achievement of burning plasma is a step toward nuclear ignition, where the process continues to fuel itself to produce energy. That reality is likely still decades away, but the scientists see these short-lived snippets of self-heating plasma as an important proof-of-concept.

“Fusion experiments over decades have produced fusion reactions using large amounts of ‘external’ heating to get the plasma hot," said lead author Alex Zylstra. "Now, for the first time, we have a system where the fusion itself is providing most of the heating. This is a key milestone on the way to even higher levels of fusion performance.”

The research was published in the journal Nature

Source: Lawrence Livermore National Laboratory

16 comments
16 comments
Bob Stuart
"Roughly the size of a ball bearing." - Could you try describe this within just one order of magnitude?
Brian M
"That reality is likely still decades away"
If there is one thing that is consistent in clean energy from fusion is that its always 20 years away!
Douglas Rogers
They should have said "bee bee". "Burning plasma" is about the same stage as the Wright flyer. It flies but that's it. When people saw it flying the quickly made serviceable airplanes.
TechGazer
The 'size of a ball bearing' comment bugged me too. I've seen bearing balls <1mm and others that would break a bone if dropped on your foot. I wonder if whoever originated that comment had ever seen any actual bearing balls, much less a variety of sizes.

As for the actual accomplishment, it seems like just another tiny step, and it's still a long way to go before a commercial reactor based on laser ignition.
Username
@Bob Stuart, Thank you!
Karmudjun
Probably ould have used a more common size reference - the size of an adult pinkie fingernail?
Ferdi Louw
For those who don't work with ball bearing every day: A ball bearing is roughly the size of a stone.
Leigh Standish
Can it become controlled and stopped if gaining strength?
Ferdi Louw
The D-T fuel pellets are about 2-3mm in diameter (like small peppercorns or a pinhead) frozen at −255 °C and then compressed to around 0.1mm in diameter.
guzmanchinky
I know everyone makes fun of fusion, but I get excited to read about the small bits of progress along the way. I do believe that this will be the limitless power we need to reach the next step of humanity.
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