13 ms·
NASA’s new shortcut to fusion power
- willis936 5y agoDo the names "Fieschmann" and "Pons" ring any bells? Here is the wikipedia article that covers these recent developments. Look in the "Later Research" section. https://en.wikipedia.org/wiki/Cold_fusion https://en.wikipedia.org/wiki/Cold_fusion
- DennisP 5y agoThe NASA research isn't mentioned there. Differences from cold fusion: they're hitting the lattice with gamma rays, and seeing 2.45MeV neutrons come out. Doesn't mean they'll achieve net power this way, or that the lattice will survive the neutrons at practical fusion rates, but they seem to be seeing D-D fusion reactions.
- ch4s3 5y agoIs it real or could there be unaccounted for neutron sources? That’s been an issue with past metal lattice setups.
- DennisP 5y agoNo idea, but it'd be odd if neutrons from another source just happened to have the energy of D-D neutrons.
- ch4s3 5y agoIf you're producing gamma rays, then you have a neutron source. This is exactly how the cold fusion people mislead themselves into thinking they had succeeded.
- danbruc 5y agoFusing hydrogen is easy, ionize it and accelerate the plasma with a voltage of on the order of 10 to 100 kV, hobbyists do this somewhat regularly. Doesn't sound too surprising that hitting hydrogen with gamma rays produces some fusion. But that's the crucial point, some fusion is not useful as an energy source, and not all fusion methods can be scaled up.
- DennisP 5y agoSure, I'm not denying that at all. It looks like real fusion happening, but might not be no more useful than fusors. They mentioned their current methods are too lossy, but they did have some interesting arguments for it being a practical energy source someday.
- ncmncm 5y agoIf they can use it to produce He3, that would be a valuable contribution independently of any energy production goal.
- fooker 5y agoI misread lattice as lettuce and was a bit confused for a while about the purpose of hitting lettuce with gamma rays!
- fernly 5y agoIndeed, came to say the same. Toward the end of the IEEE article it has this: > We’ve also triggered nuclear reactions by pumping deuterium gas through a thin wall of a palladium-silver alloy tubing, and by electrolytically loading palladium with deuterium. In the latter experiment, we’ve detected fast neutrons. "electrolytically loading palladium with deuterium" is very, very similar to the Pons/Fleischman setup, which was basically electrolysis with palladium electrodes.
- yellow_postit 5y agoAny good overviews on the different types of fusion and relative sense of liklihood to achieve their aims? I know the throwaway comment is about fussion always being 30 years away but also does appear from the outside that hype/excitement is picking up for some of the recent advances in magnetic confinement fusion.
- jyounker 5y agoNow everybody is saying 10 to 15 years, so it looks like we're getting somewhere.
- bobsmooth 5y agoGeneral Fusion's demo plant should be operational in 3-4 years.
- ncmncm 5y agoGeneral Fusion's liquid-metal reaction bubbles, unlike tokamak and stellarator, might have a future. It seems to me to depend on whether they can find a way to get the reaction rate usefully high.
- ncmncm 5y agoOr, they are starting to worry about getting their funding cut off because it will obviously never be commercially competitive with renewables.
- orthecreedence 5y ago> Existing fusion reactors rely on the resulting alpha particles—and the energy released in the process of their creation—to further heat the plasma. The plasma will then drive more nuclear reactions with the end goal of providing a net power gain. But there are limits. Even in the hottest plasmas that reactors can create, alpha particles will mostly skip past additional deuterium nuclei without transferring much energy. For a fusion reactor to be successful, it needs to create as many direct hits between alpha particles and deuterium nuclei as possible. This is one of the most clear explanations of fusion power I've read so far. Worth a read just for that alone. > And as the technology matures, it could also find uses here on Earth, such as for small power plants for individual buildings Distributed power generation is the ideal. Why bother with transporting energy when you can just generate it where you need it? Really cool article/tech. I've not heard of LCF until now. Seems promising.
- willis936 5y agoThe reason to use MCF (and why IEC can't work) is that it's okay if particles don't collide often if they are confined for sufficiently long. So what if the fast alpha doesn't collide? It's charged and thus well confined. It will transfer its energy to other particles eventually.
- PaulHoule 5y agoInertial confinement fusion works just fine if you are building a 1 megaton device driven by a fission bomb. You probably can't make it work if you're driving with a laser because the wallplug efficiency of a laser is terrible, but at least you can build a failing facility which is only huge as opposed to gargantuan. Real breakeven might be possible with heavy ion beam ignition but the minimum size facility to make an attempt is gargantuan.
- willis936 5y agoIEC is inertial electrostatic confinement: fusors and polywells. Conduction through the confinement/accelerator coils being immersed in the plasma reduces the confinement time lengths far too short for a reactor.
- perihelions 5y ago- "One promising alternative is lattice confinement fusion (LCF), a type of fusion in which the nuclear fuel is bound in a metal lattice. The confinement encourages positively charged nuclei to fuse because the high electron density of the conductive metal reduces the likelihood that two nuclei will repel each other as they get closer together." Isn't this just cold fusion? The end paragraph even credits an "International Conference on Cold Fusion".
- DennisP 5y agoNo, because of the gamma ray input.
- pdonis 5y ago> Isn't this just cold fusion? No. You still have to heat the fuel. The claim of cold fusion was tnat the fuel could just sit there at room temperature and fuse.
- drran 5y agoCosmic rays and muons can initiate a nuclear reaction: they can have very high energy sometimes. If the metal plate is large enough, then it can be hit often enough to produce significant output, when it is not shielded from cosmic rays. For example, lab at top floor or in mountain area may produce much more heat than lab in basement at sea level.
- simonh 5y agoAs many physicists pointed out at the time of the Fleischmann and Pons controversy, fusion at room temperatures may well be possible. If fact we know it’s possible because we have Fusors, and then there’s muon catalysed fusion. The problem wasn’t with the temperature range, it was with the not working and not being fusion.
- JackFr 5y ago> The problem wasn’t with the temperature range, it was with the not working and not being fusion. And them being chemists not physicists. And the University of Utah issuing a press release before the anything was peer reviewed. The whole episode is is an example of what can go wrong with science. This article shows what clearly could have been a useful and productive field of investigation became poisoned to the extent that no significant research could go on for a quarter century and still the authors have to go to great pains to distance themselves from Fleischman and Pons.
- WithinReason 5y agoSo cold fusion is viable after all, you just have make sure you call it something else so you're not laughed at. They are very careful to avoid the label: "LCF isn’t cold fusion—it still requires energetic deuterons and can use neutrons to heat them."
- pdonis 5y ago> So cold fusion is viable after all No, it isn't. There is more than just a change of name involved with LCF: the statement "it still requires energetic deuterons" means the deuterons still have to be hot. They can't be at room temperature.
- mpreda 5y agoFrom the article: Electron screening makes it seem as though the deuterons are fusing at a temperature of 11 million °C. In reality, the metal lattice remains much cooler than that, although it heats up somewhat from room temperature as the deuterons fuse. Sounds pretty much the same as room temperature to me. Also the pictures with the experimental setup suggest that the glass does not melt, which is pretty cool.
- gus_massa 5y agoThe part about "electron screening" makes no sense at all. The deuterium nuclei are in the slots between the erbium nuclei. Most of the electrons are very close to the erbium nuclei, so the slots where the deuterium nuclei are have a low electron density. Approximately the same density of an isolated deuterium atom, perhaps the double, but I doubt it's 10x higher. The orbitals of the electrons of deuterium are like 1000x bigger than the size of the nuclei. So once the incoming deuterium nuclei approach, it will be much closer to the target deuterium nuclei and it will not see the electrons. Note that most of the energy of the repulsion is when the nuclei are close, not when they are far away. The erbium are useful to keep a lot of deuterium together, but the electrons shelling is probably very small. The trick they use is to use a very energetic gamma rays that colides (indirectly) with one deuterium, and this deuterium is very fast that is the same effect you get when you have a very hot deuterium.
- nynx 5y agoI really hope this works. Honestly, there are a number of low-hanging fruits in fusion. More recent calculations show that, if you include the kinetic energy of the muons, Muon-catalyzed fusion may be net positive [0]. This LCF stuff is a low-hanging fruit too——ignored for many decades because scientists didn't want to hurt their reputations. [0]: https://en.wikipedia.org/wiki/Muon-catalyzed_fusion#Alternative_estimation_of_breakeven https://en.wikipedia.org/wiki/Muon-catalyzed_fusion#Alternat...
- was_a_dev 5y agoDo those revised calculations take into the energy requirements for generating the muons? The wikipedia article doesn't appear to give a clear answer
- smaddox 5y agoGood to see this field getting some serious investigation. Last I looked it was still very hypothetical with only questionable characters investigating.
- JackFr 5y ago> with only questionable characters investigating. Well the assumption in the physics community is that if you're investigating this field you're a questionable character, so its surprising that it got investigated at all.
- moffkalast 5y agoPhysicists look at cold fusion scientists like archaeologists do at ancient alien theorists?
- deleted 5y ago[deleted]
- nonrandomstring 5y agoHigh energy Gamma sources don't sound like a fun and easy place to get started. Maybe that's why this is a NASA project for deep space, rather than something you'll be able to buy at Tesco.
- was_a_dev 5y agoIt can be done the same way x-rays can be generated. Accelerate electrons in a magnetic field using a syncrotron.
- teeray 5y agoI’m looking forward to the work Solomon Epstein is doing in this area
- ncmncm 5y agoWillen haven been doinging.
- DennisP 5y agoThere seems to be an inconsistency in the article. First it says the Dynamitron produces gamma rays: > We can jump-start the fusion process using what is called a Dynamitron electron-beam accelerator. The electron beam hits a tantalum target and produces gamma rays, which then irradiate thumb-size vials containing titanium deuteride or erbium deuteride But later it says: > producing neutrons from a Dynamitron is energy intensive. There are other, lower energy methods of producing neutrons including using an isotopic neutron source Is the input neutrons or gamma rays?
- parksy 5y agoFrom what I gather the actual lattice requires neutrons. Their current setup uses an electron source (dynamitron) on tantalum which generates gamma rays. The gamma rays have the energy needed to push neutrons around inside the lattice. It seems they're saying it would be more energy efficient just to directly generate neutrons without having to go electron -> gamma -> neutron.
- honkycat 5y agoWe need fusion, we need more power YESTERDAY. Whatever amount we are spending to develop these moonshots it needs to be more. So many "hard things" become that much easier when we remove having to power it out of the equation. A generator for a forklift is probably unrealistic, but for a huge, skyscraper building crane? Or for one of those giant shipping barges that produce multiple percentage points of our carbon emissions? That no longer sound so crazy. Isn't that how the US powers its aircraft carriers and submarines anyway? Only with fission, which clearly is too dangerous to put on civilian ships.
- p1mrx 5y agoYeah, portable fusion would make large-scale power grids obsolete and revolutionize shipping. Things get more interesting when you scale it down to fit a passenger aircraft. I'll believe it when they can power a toaster or something.
- zw123456 5y agoFrom 2020 https://www1.grc.nasa.gov/space/science/lattice-confinement-fusion/ https://www1.grc.nasa.gov/space/science/lattice-confinement-...
- lowestprimate 5y agoHow does one extract power if it barely warms up? Does it generate electricity directly?
- pfdietz 5y agoI don't believe this. If deuterons could fuse with other deuterons in a metal lattice, this would have been seen ages ago, just by accelerating deuterons into a deuterium-loaded material. This is how neutron generator tubes work, and they've been used for longer than you've probably been alive. What happens in these tubes is the vast majority of deuterons lose energy by ionization and don't undergo nuclear reactions. There is no radical increase in fusion from electron shielding.
- drran 5y agoThis was seen ages ago. > In 1989, two electrochemists, Martin Fleischmann and Stanley Pons, reported that their apparatus had produced anomalous heat ("excess heat") of a magnitude they asserted would defy explanation except in terms of nuclear processes. They further reported measuring small amounts of nuclear reaction byproducts, including neutrons and tritium. The small tabletop experiment involved electrolysis of heavy water on the surface of a palladium (Pd) electrode. The reported results received wide media attention and raised hopes of a cheap and abundant source of energy. https://en.wikipedia.org/wiki/Cold_fusion https://en.wikipedia.org/wiki/Cold_fusion
- pfdietz 5y agoUm, no. P&F saw nothing but their own experimental artifacts. Replication of their claims failed. Their setup was also different from this NASA one, with no gamma radiation shining on the palladium (and also palladium, not titanium or erbium as used by NASA.)
- drran 5y agoMost of the replications failed, except some. My theory is that nuclear reaction in hydrogen loaded palladium is initiated by cosmic gamma rays or cosmic muons, thus those laboratories which were open to cosmic rays, such as at top floors or in mountain areas, are able to reproduce results, while shielded labs are unable. I planned to set up a similar experiment and bombard a hydrogen loaded target with muons, or move the experiment to the top of a Carpathian mountain, but the institute of nuclear research in Kharkiv, Ukraine is under attack, so it's not possible. The idea of using ErD3 instead of Nickel or Palladium is very good, because it saves weeks of time to load the target with Deuterium.
- jmyeet 5y agoI didn't see an answer to the big question I have: what about energy loss (and, to a lesser extent, container damage) through neutron loss? There is this quote: > The released neutron may collide with another deuteron, accelerating it much as a pool cue accelerates a ball when striking it. This second, energetic deuteron then goes through one of two processes: screened fusion or a stripping reaction. So a neutron "may" collide. But what if it doesn't? To be fair, the density is a lot higher an dhtere's an erbium lattice so this may just be a non-issue (or at least a much-reduced issue). Anyway, I'm glad to see alternatives to "hot" fusion being researched. I'm far from convinced the tokamak approach of massive boondoggles like ITER will ever be commercially viable.
- eutropia 5y agothis strikes me as the sort of thing that ends up as an engineering enhancement to an RTG that’s like “hybrid radio fusion heat engine” and uses a radioactive source together with this lattice confinement fusion material and end up with something like a 20% efficiency instead of the current 7.5%, but is otherwise never used outside of space probes.
- nnurmanov 5y agoThe good thing is a lot of labs across the world trying to solve this problem. Here are some I am currently watching https://e-catworld.com https://e-catworld.com, https://www.youtube.com/watch?v=z01586zdnM0 https://www.youtube.com/watch?v=z01586zdnM0
- PickledHotdog 5y agoNASA seems to achieve quite a bit with its relatively meagre budget