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Fusion energy breakthrough by Livermore Lab

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Re: Fusion energy breakthrough by Livermore Lab

#241

Post by DennisP »

operator-name wrote: post #233
hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

"That’s because they had to use 500 MJ of energy into the lasers to deliver 1.8 MJ to the target – so even though they got 2.5 MJ out, it’s still far less than the energy they needed for the lasers in the first place. In other words, the energy output (largely heat energy) was still only 0.5% of the input."

Partly that's because they use laser tech from the 1990s, with less than 1% efficiency. Now we have NIF-class lasers with over 20% efficiency.

https://physicstoday.scitation.org/do/10.1063/pt.6.2.2021102...

Re: Fusion energy breakthrough by Livermore Lab

#242

Post by idlewords »

thehappypm wrote: post #36
jeffbee wrote: post #11

I guess I don't really get it. Nobody doubts that you can get a tremendous output of energy from a fusion bomb with modest inputs. This thing they've ignited is a tiny fusion weapon without a fission blanket and with a huge, inconvenient optical primary. I mean I'm all for science but I don't see the road from this to civilian fusion power as people generally understand the term.

This is like a version 1.0 steam engine. Miniaturization and optimization can come next.

The problem is you can say that about any wildly inefficient new technology, but it doesn't always pan out.

Re: Fusion energy breakthrough by Livermore Lab

#244

Post by zaking17 »

Would anyone knowledgeable about the field update their priors about whether we’ll see commercial fusion in the next 30 years, after seeing these results? If not, is there a big milestone we’re waiting for? Or will fusion advancement be a slow grind with many small improvements over decades?

Re: Fusion energy breakthrough by Livermore Lab

#245

Post by jerf »

eloff wrote: post #235
operator-name wrote: post #233

Earlier quoted context omitted.

"That’s because they had to use 500 MJ of energy into the lasers to deliver 1.8 MJ to the target – so even though they got 2.5 MJ out, it’s still far less than the energy they needed for the lasers in the first place. In other words, the energy output (largely heat energy) was still only 0.5% of the input."

I don't see that scaling anytime soon, still more than two orders of magnitude away. But never say never.

The exact numbers depend on the form of fusion in question, but fusion does have some several places where it has quite substantial x^n growth possibilities, where "n" is definitely greater than one and can be greater than two at times, sometimes even substantially so. This means that there is some real, concrete hope for improvement in a way that, say, solar could never improve more than 4-5x where it is now because the absolutely best it could ever hope for is 100% efficiency. At the core, this is because as you get the plasma hotter and more confined, the rate of fusion goes up very quickly, much much beyond linear increases.

Re: Fusion energy breakthrough by Livermore Lab

#246

Post by zbobet2012 »

chaps wrote: post #226

“The Lawrence Livermore National Laboratory experiment shows that scientists can get more energy out than put in by the laser itself. This is great progress indeed, but still more is needed: first we need to get much more out that is put in so to account for losses in generating the laser light etc (although the technology for creating efficient lasers has also leapt forward in recent years). Secondly, the Lawrence L…

Yes, _but_ the problem of generating laser light efficiently has and is being solved for elsewhere. Which is why the NIF didn't focus on, or update their lasers. This is a major problem for semiconductor lithography for example, and receives literally tens of billions in investment every year and one which has lasers that are already 20x more efficient than the ones used by the NIF.

The real question in the experiments here at NIF was about whether inertial confinement fusion would work. This is very promising progress.

Also NIF spends a good portion of its time on weapons research, not fusion power so it's only been a recent focus.

Re: Fusion energy breakthrough by Livermore Lab

#247

Post by [deleted] »

hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

[deleted]

Re: Fusion energy breakthrough by Livermore Lab

#248

Post by tazjin »

weberer wrote: post #30
LatteLazy wrote: post #26

Earlier quoted context omitted.

Sorry, I was actually making a joke: fusion power has been described as "a decade away for the last 50 years" which I think sums it up pretty well... https://www.engineering.com/story/why-is-fusion-power-is-alw... The potential is hard to ignore, but that doesn't mean the potential will ever be achieved. This (like crypto currency) is the realm of vapourware I am afraid. Always just around the corner. :(

>vaporware Have you never heard of ITER? Its set to power on in 2025. https://en.wikipedia.org/wiki/ITER

I remember hearing about ITER back in school, a long time ago, and being told that they were just about to finally assemble the thing now.

That's pretty much the definition of vaporware, but maybe it will actually go the route of Duke Nukem :)

Re: Fusion energy breakthrough by Livermore Lab

#249

Post by cratermoon »

just like this time in 2013, https://www.science.org/content/article/fusion-breakthrough-..., and this one in 2021 https://www.sciencealert.com/for-the-first-time-a-fusion-rea...

Which definition of breakeven are they using this time? https://www.youtube.com/watch?v=JurplDfPi3U&t

Re: Fusion energy breakthrough by Livermore Lab

#250

Post by zbobet2012 »

alephnil wrote: post #234
hannob wrote: post #227

Usual caveat about all fusion "got more energy out than we put in" stories: https://backreaction.blogspot.com/2021/10/how-close-is-nucle... From a quick skimming it seems only one of the experts quoted here even mentions that (Tony Roulstone). (Update: i wrote this comment in response to another story and the comment got moved here, so it lost a bit of context https://news.ycombinator.com/item?id=33958678&ref=upstrac…

And they mention this right in the press release. Quote: “The Lawrence Livermore National Laboratory experiment shows that scientists can get more energy out than put in by the laser itself. This is great progress indeed, but still more is needed: first we need to get much more out that is put in so to account for losses in generating the laser light etc (although the technology for creating efficient lasers has also…

The NIF uses lasers produced in the 90's because their core mission isn't to make lasers better. We already have lasers which are 20x more efficient, and hitting a pellet 10*s is a trivial task. Those lasers can fire a 1khz or better. The EUV light sources for semiconductor lithography do this tens of thousands of times a second.

The goal of the research being done at NIF is to understand inertial confinement fusion. "Solving" these other problems isn't as important, other folks are solving these all day long for commercial industries already.

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