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Nuclear-fusion lab achieves ‘ignition’: what does it mean?
- isoprophlex 4y agoSo, they generated 3.15 MJ energy from the target, at a cost of an input of 2.05 MJ laser light. Pretty exciting. However those lasers aren't very efficient, generating the 2.05 MJ required more than 300 MJ of electricity. What is the path forward... Can anyone elaborate? Do we make the lasers 100x more efficient? Will hitting a target with a 100x mass yield 315 MJ? Edit: thanks everyone for the clarification. Really helps me putting the numbers in context.
- teach 4y agoApparently the semiconductor industry already has lasers that are 20x more efficient than what was used in this experiment.
- isoprophlex 4y agoInteresting, thanks! So the low laser efficiency isn't really important in interpreting the importance of this news.
- adrian_b 4y agoThe semiconductor lasers cannot produce pulses short enough for such applications. They can be used only as the pumping sources for the solid-state lasers or fiber lasers that can produce the short pulses. So the efficiencies of two lasers must be multiplied. I doubt that there is any chance to obtain an electrical to light conversion efficiency above 10%. So the energy generated by the fusion reaction should be much greater than 10 times the light energy, to be able to produce excess energy, even with lasers 10 times more efficient than now.
- dark-star 4y agoEven if semiconductor lasers could put out the power required (they can't...), a 20x improvement would still mean the efficiency is only around 20%, so you'd still be putting in 10 MJ to get out 2 MJ... Yes, it's better, but the argument still holds
- lordnacho 4y agoI don't get it. Wouldn't that mean it required 302.05MJ to get 3.15MJ?
- teach 4y agoYes. In nuclear fusion, "ignition" means that you get more energy out than the lasers impart. This is the first time anyone has pulled that off in decades of trying, which is a big deal. But practical nuclear fusion would of course require that you get out more energy _from the entire system_ than you put in, and getting there will require even more problems to be solved. But now at least one obstacle has been overcome!
- JumpCrisscross 4y ago> "ignition" means that you get more energy out than the lasers impart. This is the first time anyone has pulled that off in decades of trying, which is a big deal. The term is refreshingly intuitive. For decades we've been striking stone and flint. Sparks. We just got a bit of kindling going. It's no bonfire. But it's a big step forward.
- WithinReason 4y ago>This is the first time anyone has pulled that off in decades of trying, which is a big deal. Are you sure of that? This is from 2014: https://arstechnica.com/science/2014/02/giant-leap-for-nuclear-fusion-as-scientists-get-more-energy-out-than-fuel-put-in/?itm_source=parsely-api https://arstechnica.com/science/2014/02/giant-leap-for-nucle...
- falcor84 4y agoQuoting from the article you linked to: Hurricane’s current output, although more than the hydrogen fuel put into the reaction, hasn’t yet reached the stated goal to achieve “ignition," where nuclear fusion generates as much energy as the lasers supply. At that point it might be possible to make a sustainable power plant based on the technology.
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- femto113 4y agoScaling the NIF's approach (laser inertial confinement) isn't about more reaction mass per pulse, it's about more frequent pulses, and is probably not going to be practical or cost effective in the foreseeable future. The fuel pellets are tiny (~2mm), their container is only about 1cm and must be nearly perfectly spherical. A continuous power plant would consume about half a million of them per day (6 per second), all of which need to be shot with perfect timing, precision, and reliability to the exact center of the laser sphere. My guess is magnetic systems are much more likely to ever be used in power generation.
- laweijfmvo 4y agoThis feels important. We already know that fusion "works" (proof: look up). But it's not possible to recreate the conditions of a star on Earth. So if this method is also impractical, why would I care that it "works"?
- femto113 4y agoScientifically it's potentially very interesting: close up observation of what's going on in the center of a star and all that. I'd ignore all "the future of free clean energy is upon us at last!" hype. That's the lab and the government officials trying to drum up publicity that can then be milked for financial/political capital (it costs many billions to build and run a facility like this), coupled with lazy news outlets trying to milk sensationalist headlines for eyeballs.
- TheOtherHobbes 4y agoThis seems far more credible than the "This means fusion in ten years!" hot takes, which are - frankly - completely implausible, whether they're coming from physicists or journalists. Weapons research might be a motivator too. I would be astounded if this can be commercialised. Not because I'm cynical for the sake of it, but because I cannot in good faith see a credible engineering path which might make that possible without spectacular breakthroughs in a number of disciplines. MCF seems more likely to get somewhere. But my best guess is that advances in renewables will have made fusion redundant within ten years. There is far more scope for incremental and affordable improvements in collection, distribution, and storage than there is for the Big Science breakthroughs required to build one commercially viable ICF plant.
- iamgopal 4y agoLet’s say there are 20 different system used to make this ( laser powering, energy collections, target energy density etc etc ) , we only need to make 10 of those system 200 percent efficient to increase overall efficiency to 1000 times , within range of usefulness, I think we will be achieve this.
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- already 4y agoMore discussions: https://news.ycombinator.com/item?id=33971377 https://news.ycombinator.com/item?id=33971377
- teach 4y agoThis article was a welcome relief after many of the others the past couple of days. Well-written, clear, optimistic but not hand-wavy, and certainly not "breathless" or loaded with PR.
- habibur 4y agoIn more human terms : They fused in 0.6 kwh energy. Which produced 0.9 kwh energy. These megajouls are confusing for me. kwh is what we use for resident home power billing unit.
- freedom2099 4y ago
- habibur 4y agoPeace.
- mettamage 4y ago> Joules it’s a pretty fitting unit… we are talking about energy in the form of heat here… kWh is a u it used for electricity! Didn’t you study physic in high school? I'd rephrase this to: Joules it’s a pretty fitting unit. We are talking about energy in the form of heat here, kWh is a u it used for electricity. The question at the end comes of as potentially condescending. I'm not sure if you're aware, which is why I'm mentioning this rephrase.
- freedom2099 4y agoI was being condescending!
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- michaelmrose 4y agoYou could communicate as much without the last insulting sentence delivered for no particular purpose. It elevates the discussion and keeps you from ending up banned.
- mettamage 4y agoAlright, thanks for being frank. I like HN because usually people do their best to be the opposite (aka as helpful as possible while being respectful). I like that attitude more than a condescending attitude which is one of the reasons why I love it here. Moreover, it's even in their guidelines. It's part of the culture to take arguments in good faith, it's part in the culture to see the best in people's arguments and to be fact based/scientific. The guidelines are here, I recommend you to read them: https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html And we all make mistakes on it every now and then. I am no different, rereading them from time to time helps keeping this community as awesome as it is :)
- phtrivier 4y agoInformative and sobering. That's what we need, not press conferences.
- AnimalMuppet 4y agoI don't know. This is not "we're there", not by a long shot. But it still seems to me to be worth throwing a lot of confetti over.
- dougmwne 4y ago“However, while the fusion reactions may have produced more than 3 megajoules of energy — more than was delivered to the target — NIF’s 192 lasers consumed 322 megajoules of energy in the process.” Well that says it all right there and really cuts through all the fluff on this story. Sounds like a nice milestone that has absolutely nothing to do with our ability to get a useful amount of energy back out. We are still at least 2 orders of magnitude away from a power source.
- d23 4y agoDo you have a background in this field?
- dougmwne 4y agoI do not. I would say if I did.
- TheCondor 4y agoThis is closer to pure science. This is in a lab. They aren't even attempting to make a "power source" so much as testing and verifying the theory.
- dougmwne 4y agoAnd that is great! My issue is the way the science is reported in the media making it sound like we are on the cusp on some kind of energy revolution, when we very much are not and don’t even have a line of sight on it yet. But then I suppose public hype will lead to Congress dollars and nothing gets done without those.
- cainxinth 4y agoIt means practical fusion power, which has been 20 years away for the last 60 years, will now be just 10 years away for the next 30 years.
- trhr 4y agoFollowed, of course, by being 5 years away for the next hundred years. Big oil is much more competent adversary than science.
- MichaelZuo 4y agoWell not even that, there isn't even a roadmap to improve laser efficiency 100x Even a 90% efficient high powered laser is way beyond fusion in terms of technical difficulty.
- pdabbadabba 4y agoBut am I wrong in thinking that it’s conceivable that we could see a further doubling in Q-plasma? If that happens, perhaps along with significant-but-plausible improvement in laser efficiency, then things could start to look fairly promising.
- MichaelZuo 4y agoDid you reply to the wrong comment?
- pdabbadabba 4y agoNope! My point was that your comment assumes no further increase in Q-plasma. But the experience of the last few years suggest that there’s reason to hope that won’t be the case. We can come at the problem from both sides.
- crispyambulance 4y agoDidn't someone the same thing about atomic power back in the middle ages? But that's OK, fusion is a hard thing to do outside of a star. It may take decades longer for it to be practical but doesn't the potential return on investment make it worthwhile to keep working on it now?
- carabiner 4y agoNever thought I'd witness a resonance cascade... Let alone, create one.
- dvh 4y agoCan someone calculate how much installed solar power could we get by pausing fusion r&d for the next 10-20 years?
- SoftTalker 4y agoNot enough.
- coolspot 4y agoAbout zero if China refuses to sell us solar panels due to some conflict.
- rs_rs_rs_rs_rs 4y agoCall me a cynic but the only meaningful thing out of this is that they got their funding secured.
- olliej 4y agoIt’s really stretching things to say it produced more energy than went into the reaction. Energy in:energy out is a ratio of the amount of energy that goes in, not the portion of the energy that eventually hits the target. It’s like measuring car engine efficiency by measuring how much of the energy reaching the wheels translates into motion - and ignoring the massive losses that lead up to that point.
- dotancohen 4y agoUsing your analogy, this experiment was to see if more energy could be imparted as motion then was put into the tires from the engine, due to a mechanism of physics of the tires that would release energy. Many people doubted our ability to exploit this mechanism of physics. Now that our ability to exploit this mechanism of physics has been demonstrated, development of power sources that exploit this mechanism can begin to receive funding.
- didibus 4y ago> The US$22-billion ITER project — a collaboration between China, the European Union, India, Japan, Korea, Russia and the United States — aims to achieve self-sustaining fusion, meaning that the energy from fusion produces more fusion It's refreshing to see collaboration like this still happening, even with all the tensions between all those countries.
- coolspot 4y agoIt was happening for decades. Unclear how the war affects it now, but I believe most RU hardware (cryo and magnets) was already delivered/installed.
- zbobet2012 4y agoThis is the third thread today with pithy "this means nothing takes". If you're thinking of posting a one liner on the subject you should probably stop. Let's save some time out of discussion now: 1. The lasers at NIF are not designed to be efficient, and they are very old. Modern semiconductor lasers are 20x more efficient. The 300MJ wall plug conversation is stupid, stop pointing it out. 2. Dropping crystals and hitting them with lasers is not hard, we do it in semiconductors for EUV light source generation all the time. In fact EUV light sources do it at 100khz or more. 3. Power extraction from a bundle of hot material is not a particularly unknown problem. It's in fact how every power plant on the planet works. Make no mistake there are a lot of engineering problems to solve. The "droplets" are enormously expensive, the "firing" itself creates debries which need cleared from the chamber, dt supply is not something that's readily available in large quantities, blah blah. I'd love interesting conversation about what stands between ICF and a real energy plant, not hot takes.
- jjtheblunt 4y ago> Power extraction from a bundle of hot material is not a particularly unknown problem. It's in fact how every power plant on the planet works. River power spinning a generator? Wind farm power? Are those counterexamples?
- falcor84 4y agoWell, these aren't "bundles" per-se, but as I understand it, both are relying on the Earth-as-a-system converting heat from the sun falling on particular areas into large-scale flows, which we humans can then hook into.
- manmal 4y agoGP was likely referring to power plants that burn things in order to heat up water to make steam in order to rotate an iron core encircled by copper wire. Using kinetic energy like wind or flowing water is a nice shortcut to the rotating iron core. Even nicer: Cut out the rotating iron core and directly produce voltage via photons hitting a semiconductor. I share GP‘s sentiment though that, in the end, there are remarkably few concepts at the bottom layer of electricity production. (There are other means of course, but they are not in use for power generation in amounts that can drive even one household, AFAIK)
- everyone 4y agoI read a comment here before saying that the purpose of the NIF is to get more data for making hydrogen bombs, while being unable to test actual bombs due to treaties. And that the press releases they have about fusion energy are mainly bullshit for the press. Is there anything to that claim or is it bullshit?
- dotnet00 4y agoPart of their job is to make sure that the nuclear stockpile is still reliable. Since they can't actively blow up a nuke nowadays, they instead rely on experiments and simulation. However, like a lot of the Department of Energy's work, their nuclear research also relates heavily to civilian applications. They are not 'bullshit' for the press.
- androtech 4y agoThis is quite frankly awesome. Now if it's sustainable, we could definitely use the power to do desalination plants here on the west coast, since it's a super energy hungry process. And the hydrogen/deuterium could come from the salt water its processing. Then, it's just a matter of what to do with the salt generated.
- cpleppert 4y ago"To demonstrate that the type of fusion studied at NIF can be a viable way of producing energy, the efficiency of the yield — the energy released compared to the energy that goes into producing the laser pulses — needs to grow by at least two orders of magnitude." Lots of claims on HN that we were one order of magnitude away. Similar claims were made in other threads made about how we were really close to commercialization with better lasers. This article has the right take, this research is valuable but its impossible to say anything about whether indirect intertial confinement fusion is commercially viable. Best case scenario [1], we still have a way to go. [1]: An Assessment of the Prospects for Inertial Fusion Energy (2013)
- ZeroGravitas 4y agoThis means we might have power as cheap and plentiful as solar and lithium batteries are today in a couple of decades, when solar and Batteries will be even cheaper.
- Schroedingersat 4y agoThat's a little optimistic. Or do you mean in the arctic or something?
- moloch-hai 4y agoIt is not a nuclear-fusion lab. It is a nuclear-weapons lab. What it means is they got a better system to model weapons. What it means to DoE higher-ups is that if they paint it as a breakthrough in energy production, they can unlock funding increases. So they do.
- jboy55 4y agoIts so frustrating to see so many people not understand this means relatively nothing towards the goal of power generation. We'll see how many details are released to the public and other scientists and how much is kept top-secret. They very well could have achieved this 10 years ago using similar materials as in the h-bomb, but kept that secret.
- choeger 4y agoIf I am not mistaken, there is also no current technology to actually harvest that energy, right? So the lasers need at least 10x the energy they themselves put into the target. Conversion is still unclear. Are we even at 1% to a demo reactor, let alone a commercially viable one?
- jujube3 4y agohttps://backreaction.blogspot.com/2021/10/how-close-is-nuclear-fusion-power.html https://backreaction.blogspot.com/2021/10/how-close-is-nucle...