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MIT-designed project achieves major advance toward fusion energy

915 points by klintcho 5y ago

dfdz 5y ago
The thumbnail of the youtube video made me laugh Smaller. Smarter. Sooner. 2018 Currently 2021 where is my fusion energy? But this time must be different, after this advance we are only a few years away from fusion energy?
- bwestergard 5y ago
  They seem to have made two claims. First, that they have a qualitatively different design that requires a significantly stronger magnetic field. Second, that they could build a magnet that produces such a field. They are now claiming to have done the latter. Are you skeptical of the new design? Or do you think it does not represent as significant a departure from earlier designs as they claim?
- ChrisMarshallNY 5y ago
  The running joke has always been that “Fusion is 20 years away,” and has been, for the last 50 years. I really want this to work. I am a bit concerned, with how “the old guard” will react, once we have successful, productive, fusion. I foresee an astroturf NIMBY campaign against construction of fusion plants.
  - soperj 5y ago
    It wasn't a joke, it was always based on an adequate level of funding. Everything is always off in the future if it never gets funded.
    - JackFr 5y ago
      Ah yes, and how much money? The answer always seems to be “More”.
      - MauranKilom 5y ago
        Please consult this graphic from 1976 if you are actually interested in the answer. https://i.imgur.com/3vYLQmm.png https://i.imgur.com/3vYLQmm.png
        drdeca 5y ago
        Could you clarify how to read this chart? The y axis is, funding given different plans? Or.. I got the impression that this is meant to depict a relationship between when practical fusion would be developed and how much funding it receives, but I don’t see how to get that from the chart. Also, not sure why imgur has that image marked as adult content.
        MauranKilom 5y ago
        These are projections made in 1976. They can be read as different project plans made at that time for different amounts of funding. For example, "if we follow the blue plan, it would require 9 billion (2012) US dollars of funding in 1982 (etc.) and we would achieve fusion by 1990." The 1976 projection was that, assuming funding was kept at the level of 1976 (~1 billion a year), fusion would not be achieved in the foreseeable future. It further shows that actual funding has been below that level. In short: Yes, getting fusion off the ground sooner would have required more money. Not "always more", but more than "we project no success" levels.
        pfdietz 5y ago
        Those plans would not have worked, though. They were for programs that assumed tokamaks worked better than they actually do. And by the 1980s it was realized (Lidsky; Pfirsch and Schmitter) that heat transfer limits would make any tokamak power plant unattractive.
      - apendleton 5y ago
        I mean, yes, obviously if the criticism is that they're getting too little money, clearly they want more. Some technologies are fundamentally expensive to develop (the Apollo program, the Manhattan project, etc.). That doesn't mean the people saying so are automatically charlatans, especially given that they've never gotten what they've asked for -- it's not like some bomber development project where they get what they want and then keep coming back for more. The relatively paltry amounts the US has been devoting to fusion energy research are lower than any of the scenarios laid out in a 1976 DOE planning document[1] about what it would take to achieve fusion power, and lower even than just continuing at 1970s levels (a plan they labeled in that document as "fusion never"). [1] https://books.google.com/books?id=KSA_AAAAQBAJ&lpg=PA234&ots=vl9dP06svu&dq=%22possible%20paths%20to%20a%20reactor%20from%201976%22&pg=PA234#v=onepage&q&f=false https://books.google.com/books?id=KSA_AAAAQBAJ&lpg=PA234&ots...
  - phicoh 5y ago
    At the moment it is very far for clear that fusion will be cost effective. The article says this about the fuel of fusion: "The fuel used to create fusion energy comes from water, and “the Earth is full of water — it’s a nearly unlimited resource. [...]" They forgot to say that it is not the H2O that comes out of your tap. The earth is especially not full of tritium.
    - apendleton 5y ago
      The plan is for them to breed their own tritium, though, so the consumables coming in the front door would just be deuterium and lithium, both of which (while less common than tap water) are not rare.
      - eropple 5y ago
        My understanding (and I am a layman) is that lithium isn't that accessibly common on Earth, and that we're doing a bang-up job of using as much of it as we can get our hands on already. Are there practical methods of extracting less accessible lithium that don't themselves have nasty side effects?
        apendleton 5y ago
        Yeah, there have been rumblings about recovering it from seawater: https://electrek.co/2021/06/04/scientists-have-cost-effectively-harvested-lithium-from-seawater/ https://electrek.co/2021/06/04/scientists-have-cost-effectiv...
        dodobirdlord 5y ago
        The amount of lithium required for these purposes is absolutely trivial.
    - rory 5y ago
      The fuel for fission comes from rocks. The Earth is full of rocks!
      - 5y ago
  - Krasnol 5y ago
    You don't need an astroturf. Nuclear ruined it's own reputation for generations though hopeful not as long as they'll have to care for the waste we already have.
    - UnFleshedOne 5y ago
      What ruined nuclear reputation is environmentalists who don't actually care for environment.
      - ncmncm 5y ago
        What ruined nuclear's reputation is corruption, and being the most expensive choice. (Although coal will end up overwhelmingly more costly, in the end!) Would it be so expensive without corruption? Who can say? Corruption is wired into the process. We are purely lucky that, for structural reasons, corruption is minimal on solar and wind projects. Probably this is because what it ought to cost is readily visible from the outset. There just isn't enough fat to attract graft.
        UnFleshedOne 5y ago
        Yeah, most expensive choice, unless you count externalities of coal.
      - Krasnol 5y ago
        Parroting Shellenberger will never make you look like a serious participant in this discussion.
        UnFleshedOne 5y ago
        Haven't read his books, I must have gotten his ideas by osmosis. Now reading criticism of the books on his wiki page, I think his critics are not concerned with environment any further than it aids their real case if the quote below is a representative sample: "criticizing [The Death of Environmentalism: Global Warming in a Post-Environmental World] for demanding increased technological innovation rather than addressing the systemic concerns of people of color."
  - AnimalMuppet 5y ago
    Per a comment by nielsbot, they're saying 2025. So, four years away, not 20. That's progress...
    - ncmncm 5y ago
      That is production of hot neutrons, not electrical power. Actual electrical power is still decades away... or would be if anybody bothered to try building it. Cost-effective electrical power from Tokamak is never. FRC, though, maybe. But you would have to have people actually working on that.
  - MisterBastahrd 5y ago
    Fusion is the Linux Desktop of energy projects.
    - TheGoddessInari 5y ago
      Will fusion also occur then due to the mishandling of Windows 11?
  - nixass 5y ago
    "Fusion is always 50 years away" for a reason https://www.reddit.com/r/Futurology/comments/5gi9yh/fusion_is_always_50_years_away_for_a_reason/ https://www.reddit.com/r/Futurology/comments/5gi9yh/fusion_i...
    - pfdietz 5y ago
      With respect to that graph: tokamaks turned out to not work nearly as well as the plans embodied there assumed (and because engineering obstacles were not sufficiently publicly acknowledged at the time). If funding has not been as high as hoped, it's because stakeholders don't really exist for fusion. The utilities have never thought much of it.
  - ncmncm 5y ago
    There will be no need for NIMBY: fusion power is necessarily 100x+ more costly than solar + storage. The only real open question is how long the gravy train will run before the plug is pulled. F-35 and SLS have demonstrated that with careful management, that can be longer than anyone could have believed.
- baking 5y ago
  The company was founded in 2018. At the time they promised to demo this magnet during the Summer of 2021. What is the issue? The goal is to get fusion power om the grid in the 2030's and scale up in the 2040's. Stop moving the goalposts.
criticaltinker 5y ago
The advances enable a magnetic field strength that would otherwise require 40x more volume using conventional technology - doesn’t the reduced volume imply the plasma temperature would also increase significantly? Or is the magnetic field strong enough to protect the walls of the chamber?
- tppiotrowski 5y ago
  My understanding is that the volume of the magnet is smaller and thus the entire reactor size goes down significantly leading to lower cost. ITER was designed to use weaker electromagnets and therefore needs a massive building and tons of cranes and a massive budget.
  - pfdietz 5y ago
    The ARC reactor design has 10x the volumetric power density of ITER. Unfortunately, the ARC design also had 40x worse power density than a PWR primary reactor vessel.
    - apendleton 5y ago
      Is that the right metric? You wouldn't need to build a huge containment structure around it like you would for a PWR, so I'd imagine the power density of the plant as a whole wouldn't be anywhere near 40x worse. Why focus just on the primary reactor vessel?
      - pfdietz 5y ago
        Because the rest of the power plant will be similar (or also worse for fusion; consider the tritium handling facility or the robotic equipment for maintaining the fusion reactor). You would need a confinement structure, just to keep the tritium in (which will leak all over even in normal operation). So if you swap out a cheap PWR reactor for a much larger, and hence much more expensive, fusion reactor, you get a power plant that costs more than a fission power plant. Viewed another way: if you could make a fission reactor with a power density as low as ARC, it would have so much thermal inertia that meltdowns would be essentially impossible. You should then ask why such fission reactors are not built.
shmageggy 5y ago
These university press releases are always very positively framed. This one makes the new magnet seem incredibly promising and fusion seem like almost an inevitability now, but decades of failure have us conditioned for skepticism. What's the catch this time?
- stormbrew 5y ago
  I'm not sure it's possible for "lay people" (of which I am one) to recognize the difference between a very slow success and "decades of failure". Very little is invested into fusion power as a project, overall. So advancements seem to come when outside influences cause breakthroughs. I wonder how different the world would have been if it had for whatever reason been easier to produce fusion power than a fusion bomb. Military investment into the bomb would have probably pushed things forward a lot quicker. As is, the US military built thermonuclear bombs very quickly and then the appetite for advancement just dried up.
  - fshbbdssbbgdd 5y ago
    You could say that military investment into fusion and fission bombs was groundwork for everything done since. On the other hand, the fact that nuclear power started with bombs probably contributed to it falling out of favor and being regulated to irrelevance (even though hydrocarbons have been responsible for a lot more deaths and environmental damage).
- phkahler 5y ago
  >> What's the catch this time? There are a bunch of issues still to be resolved. Higher magnet strength is/was just one of many.
  - ncmncm 5y ago
    That the most expensive parts of the plant would be quickly destroyed by neutron irradiation is another. That it would cost overwhelmingly more than solar+storage is what will ultimately kill it. Someday. Many more $B will be spent first.
xqcgrek2 5y ago
Ah, a university press release. Nah.
sdeyerle 5y ago
In the original proposal for the ARC reactor, they were proposing making the magnet separable so the top and bottom of the reactor could be separated and the vacuum vessel removed. (See pg. 5 of https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja032/15ja032_full.pdf https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja0...) It doesn't look like they are targeting that here. Does anyone know if that is ARC (not SPARC) specific, or if that has been abandoned?
- nielsbot 5y ago
  The article says this is from an "MIT-CFS collaboration" which is "on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. That demonstration device, called SPARC, is targeted for completion in 2025." So, sounds like it's for SPARC.
  - sdeyerle 5y ago
    Yeah, they are definitely building SPARC. I had just been under the impression they were trying to do the separable magnets in SPARC, and was curious if I misunderstood their plan or if their plan had changed.
    - nielsbot 5y ago
      Yeah--I misread your question. :)
- deleted 5y ago
  [deleted]
- ncmncm 5y ago
  Since there is no actual use planned for any power released in this gadget, no maintenance will be performed. When they finish playing, they scrap it, pocket the money, and go their separate ways. No commercial reactor will ever be built, so this is just for showing off. The only real good to come from these efforts is employment of plasma fluid physicists. I just hope non-military work can be found for them when this stuff fizzles. Solar Physics is fascinating and important, but has limited budget.
Seanambers 5y ago
If anyone have not seen it i recommend this video as a primer for fusion technology, it's from MIT. https://www.youtube.com/watch?v=L0KuAx1COEk https://www.youtube.com/watch?v=L0KuAx1COEk The video thouches upon magnetic fields and its relevance at this time mark ; https://youtu.be/L0KuAx1COEk?t=2880 https://youtu.be/L0KuAx1COEk?t=2880
mzs 5y ago
SPARC yttrium barium copper oxide (YBCO) high temp (10-70K) superconducting magnets
jcfrei 5y ago
Lots of negative comments in this thread. I've been following CFS for a few years now and I honestly believe this is an historic event - probably the beginning of the "fusion age".
- phscguy 5y ago
  Yeah, any positive news on fusion progress and there always seems to be the same set of comments appear that are overwhelmingly critical of fusion development. Fusion is not well funded and imo has been let down by mismanagement of ITER, and despite this keeps making progress. I feel that fusion is one of humanity's best shots at actively reversing climate change, and it is disheartening to see such widespread pessimism about it. Yeah it's hard. There are huge hurdles in making it economicly viable, but if we can go from first powered flight to the moon in 70 years, and put billions of transistors on a chip in 50, then maybe we can get fusion going. It's clearly possible.
  - UnFleshedOne 5y ago
    There is a species of environmentalism that would consider successful fusion or similar high tech mega scale energy source actually detrimental because you can't build one in your hippy community using old tractor parts and alternative ways of knowing. Environmentally clean energy source is not enough, it needs to be ideologically pure as well.
    - pfdietz 5y ago
      This is projection. The irrationality is thinking that fusion is something desirable. I suspect this follows from exposure to fusion reactors as a trope in SF stories. From a hard nosed engineering point of view fusion is just terrible.
      - sprafa 5y ago
        Please tell me how it’s terrible, Mr Hard Nosed Engineer ?
nielsbot 5y ago
Update: They have a press release on their website https://cfs.energy/news-and-media/cfs-commercial-fusion-power-with-hts-magnet https://cfs.energy/news-and-media/cfs-commercial-fusion-powe... In case others are wondering, looks like this is for SPARC. FTA: This "MIT-CFS collaboration...on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. That demonstration device, called SPARC, is targeted for completion in 2025." CFS: https://cfs.energy/technology https://cfs.energy/technology (edit: clarification)
noobermin 5y ago
University press releases need not be peer reviewed so they can get close to saying things that would offend other scientists and get away with it. The key phrase in "the most powerful magnetic field of its kind ever created on Earth" is "of its kind." Creating a many telsa magnetic field has been done in other experiments like with lasers[0], only they are physically smaller in size and last for nanoseconds, it's just of this size, stability and with the high temperature superconductors that makes it special. If the claim is just the magnitude of the field they've already been beat. [0] https://www.nature.com/articles/s41467-017-02641-7 https://www.nature.com/articles/s41467-017-02641-7 Just as a note, the max B field here is 600T
- zardo 5y ago
  I think "it's kind" refers specifically to a magnet for plasma containment. As this doesn't set the record for a REBCO magnet. https://nationalmaglab.org/news-events/news/lbc-project-world-record-magnetic-field https://nationalmaglab.org/news-events/news/lbc-project-worl...
freeopinion 5y ago
Let me know when the advance comes from Elizabethtown Community and Technical College. That would probably be affordable to put in production.
FredPret 5y ago
It's now only twenty years away!
dfdx 5y ago
Plenty of skepticism in these comments. I've been following CFS for a while and can present a point of view for why this time might be different. Fusion energy was actually making rapid progress in the latter half of the twentieth century, going from almost no power output in the fifties and sixties to a power output equal to 67% of input power with the JET reactor in 1997. By the eighties there was plenty of experimental evidence to describe the relationships between tokamak parameters and power output. Particularly that the gain is proportional to the radius to the power of 1.3 and the magnetic field cubed. The main caveat to this relationship was that we only had magnets that would go up to 5.5 Tesla, which implied we needed a tokamak radius of 6 meters or so in order to produce net energy. Well that 6 meter tokamak was designed in the eighties and is currently under construction. ITER, being so large, costs tens of billions of dollars and requires international collaboration; the size of the project has led to huge budget overruns and long delays. Recently however, there have been significant advances in high-temperature super conductors that can produce magnetic fields large enough that we (theoretically) only need a tokamak with a major radius of about 1.5 meters to produce net gain. This is where SPARC (the tokamak being built by the company in the article) comes in. The general idea is that since we have stronger magnets now, we can make a smaller, and therefore cheaper tokamak quickly. Small tokamaks do have downsides, namely that the heat flux through the walls of the device is so large that it will damage the tokamak. There have been breakthroughs with various divertor designs that can mitigate this, but to the best of my knowledge I'm not sure that CFS has specified their divertor configuration. This was just a short summary of the presentation by Dennis Whyte given here [0]. I do not work in the fusion community. [0] https://www.youtube.com/watch?v=KkpqA8yG9T4 https://www.youtube.com/watch?v=KkpqA8yG9T4
- zetalyrae 5y ago
  I've always wondered: why exactly is ITER so expensive, and slow? Is the engineering required at such a standard that it should takes decades of planning and construction and tens of billions of dollars? The timeline is so dilated (started in 1988, first plasma planned for 2025!) it feels like the kind of project that's expected to be cancelled from the start. It just doesn't strike me as obvious that reducing the major radius by a few meters would have such a huge impact on cost/timelines.
TrainedMonkey 5y ago
This is exciting. Magnetic field strength is a key component for enabling magnetic confinement fusion. This is because energy gain and power density scales to the 3rd and 4th power with magnetic field strength but only ~linearly with reactor size. See following equations for more details: https://youtu.be/xJ2h3vbOag4?t=306 https://youtu.be/xJ2h3vbOag4?t=306 So, why is this particular announcement exciting? There are 3 factors: 1. This is a high temperature superconductor. I can't find any references, but as far as I remember the substrate they are using needs to be cooled to (WRONG, it was cooled to 20degK, see reply by MauranKilom) 60-70 degK to achieve super conductivity. Compare to magnets used in ITER which need to be cooled to 4degK. This is the difference between using relatively cheap liquid nitrogen vs liquid helium. 2. Field strength of 20 Tesla is significantly higher than 13 Tesla used in ITER. Given that magnetic confinement fusion scales significantly better with field strength vs reactor size, this will enable much smaller reactor to be power positive. See following links for more details on ITERs magnets: https://www.newscientist.com/article/2280763-worlds-most-powerful-magnet-being-shipped-to-iter-fusion-reactor/ https://www.newscientist.com/article/2280763-worlds-most-pow... https://www.iter.org/newsline/-/2700 https://www.iter.org/newsline/-/2700 3. Finally, the magnet was assembled from 16 identical subassemblies, each of which used mass manufactured magnetic tape. This is significantly cheaper and more scalable than custom magnet design/manufacturing used by ITER. The kicker is how 3 of the factors above interact with the cost of the project. Stronger magnets allow smaller viable reactors. High temperature superconductors + smaller reactors allow for a much simpler and smaller cooling system. Smaller reactors + scalable magnet design further drives down the cost. Finally, cost of state of art mega projects scales somewhere between 3rd and 4th power with the size of the device. Combining all of the above factors, SPARC should be here significantly sooner than ITER and cost a tiny fraction (I would guesstimate that fraction to be between 1/100 and 1/10,000). edit: typos + looked at the cost of ITER and refined my cost fraction guesstimate + corrected some stuff based on the reply by MauranKilom.
- MauranKilom 5y ago
  Appreciate the rundown of why this is important! > This is because energy gain and power density scale exponentially with magnetic field strength but only linearly with reactor size Nit: It scales polynomially, not exponentially. Specifically (according to those formulas) energy gain scales with the cube of field strength and power density with the fourth power. Still massive scaling indeed, but exponentially would be something else. > as far as I remember the substrate they are using needs to be cooled to 60-70 degK to achieve super conductivity The video in the article shows 20 K. Could of course be that higher temperature is feasible and they just played it safe (or the video is wrong).
john_yaya 5y ago
The magnets are a problem to solve, but not the biggest problem by far. Solve for neutron embrittlement of the reactor parts, and then you’ll start to have some credibility.
NiceWayToDoIT 5y ago
I remembered that in 2018 Japanese team manage 1200 T peak power. http://www.sci-news.com/physics/strongest-magnetic-field-achieved-indoors-06420.html http://www.sci-news.com/physics/strongest-magnetic-field-ach... In comparison, 20T does not look much, but again it is, I wonder with the Japanese technique what is the highest continuous magnetic field.
- uj8efdjkfdshf 5y ago
  These high magnetic fields are generated using flux compression[0], in which the incompressibility of magnetic field lines means that compressing the coils generating the magnetic fields will increase the strength of the resultant magnetic field. However, the implosion process permanently destroys the magnet, which makes it highly unsuitable for continuous use and certainly shouldn't be used anywhere near your fusion reactor. [0] https://en.wikipedia.org/wiki/Explosively_pumped_flux_compression_generator https://en.wikipedia.org/wiki/Explosively_pumped_flux_compre...
- pfdietz 5y ago
  1200 T has a magnetic pressure of about 5.7 megabars (about 20x the detonation pressure of high explosives). Such high fields can only be achieved very briefly in devices that explosively disassemble.
sbierwagen 5y ago
Every mass-media article on fusion seems obliged to use "the fuel comes from water" line. I wonder if a "just says in mice" style harassment campaign would get journalists to stop saying this.
- ncmncm 5y ago
  Journalists quote promoters. When something has no reasonable prospect of ever producing, promoters resort to lying. Journalists are not responsible for it, although experience should make them less credulous. But pie in the sky sells better than skepticism.
- rpmisms 5y ago
  The journalists are saying that because the PR people tell them that. If I were doing PR for a fusion project, I'd sell that aspect hard—it's technically true, and sounds great.
fnord77 5y ago
so what is the most feasible approach? NIF's inertial containment or mini-tokamak?
kgarten 5y ago
Better title: Startup builds strong magnet that might be useful for a fusion plant.
pcj-github 5y ago
If we had "an inexhaustible, carbon-free source of energy that you can deploy anywhere and at any time" we'd wreck the planet faster than we already are... I guess at least a few could escape though.
- maccam94 5y ago
  I'm curious whether we could cool the planet by pulling CO2 out of the air with scrubbers powered by fusion reactors, or if their heat output would cancel it out. Removing the CO2 would have the benefit of being an exponential thermal decrease (the planet gets less hot from the sun each day), and heat output from fusion plants should scale linearly with the rate at which the CO2 scrubbers run, so it's possible the scaling properties would work out...
  - sprafa 5y ago
    Unfortunately I predict that when we “stop” global warming will likely be when we stop changing the climate (at least in that way). This is because a lot of rich countries seem to me to be well placed to benefit partially from global climate change at the moment, at least within the 1-2C range. Changing the climate past that point is likely to be controversial, since the countries who now benefit from the situation will likely not want to give those newfound advantages away. I would think of it a lot as the end result of a war - the borders are defined by where the armies stopped ie the division of Europe and Asia after ww2. After climate change I expect whoever has benefitted from it to defend their position and reject any further alterations!
  - ncmncm 5y ago
    Since power from a fusion plant would cost 100x+ what solar and wind cost, no. But every cent diverted to fusion from solar brings climate disaster closer.
    - gfodor 5y ago
      Do you have a reason to believe capital deployed to fusion would have been deployed to solar? And if so, why do you think it would make a difference, given the market feedback loop going on with solar driving down costs? Edit: also, your comments seem to be incredibly negative on fusion, would you mind disclosing if you have any solar or wind connected conflicts of interest?
cletus 5y ago
I've long been skeptical of ITER making any sense given its insane cost. I mean even it succeeds, then what? Here's the truth: there's no such thing as free energy. Even if the fuel is so abundant it's actually or effectively free (eg deuterium), the energy isn't. Say it takes $50B to build a plant that produces 1GW of power, which I'll estimate at about 7TWh/year based on [1]. Let's also say it has a lifespan of 40 years and an annual maintenance cost of $1B going to up to $2B in the last 10 years. So that's 40 years for 280TWh at a cost of $100B, which equates to $0.35/kWh if my math is correct. I realize ITER isn't a commercial power generation project. My point is that people need to stop getting hung up on the fuel being "free". The lifetime cost of the plant can still make it completely economically unviable. Second, the big weakness of any fusion design is neutrons. The problem people tend to focus on is that neutrons destroy your (very expensive) containment vessel with (one of my favourite terms) "neutron embrittlement". As an aside, hydrogen fusion also produces high speed helium nuclei, some of which tend to escape and this is a problem too because Helium nuclei are really small so can get in almost any material, which is a whole separate problem. But here's another factor with neutrons: energy loss. High speed neutrons represent energy lost by the system. To combat these problems we've looked for alternatives to hydrogen-hydrogen fusion, the holy grail of which is aneutronic fusion. The best candidate for that thus far seems to be Helium-3 fusion but He-3 is exceedingly rare on Earth. I really think we get caught up on the fact that this is how stars work but stars have a bunch of properties that power plants don't, namely they're really big and they burn their fuel really slowly (as a factor of their size), which is why they can last billions or even trillions of years. Loose neutrons aren't really an issue in a star and sheer size means gravity keeps the whole system contained in a way that magnets just can't (because neutrons ignore magnetic fields). So I hope they crack fusion but I remain skeptical. Personally I think the most likely future power source is space-based solar power generation. [1]: https://en.wikipedia.org/wiki/List_of_largest_power_stations https://en.wikipedia.org/wiki/List_of_largest_power_stations
- sdenton4 5y ago
  If only there were some way to capture and use all that power from the giant fusion reactor in the sky...
- mLuby 5y ago
garbagecoder 5y ago
It just a decade away!!
JDDunn9 5y ago
Even if we can get fusion to work, it will never be economical. Just because the fuel (water) is free, that doesn't make the energy free. The fuel rods for fission power plants are already a rounding error in the cost of energy. It's the capital costs that dominate the equation, and fusion plants will be at least as expensive as fission, which is more expensive per KWh than solar. https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre-cracked-up-to-be/ https://thebulletin.org/2017/04/fusion-reactors-not-what-the...
- gfodor 5y ago
  You’re citing an article from 2017 talking about a reactor design from 1988 in response to an article about novel fusion technology from 2021.
  - loufe 5y ago
    I agree that the sourcing does seem off in JDDunn9's post but your comment doesn't invite further discussion much.
deleted 5y ago
[deleted]
derac 5y ago
SPARC is an amazing project. Congrats on this milestone! I am optimistic about SPARC and ARC. I'd love to hear legitimate critiques, though. I see a lot of negative comments on ITER, which is a very different situation. ITER will teach us a great deal btw, it isn't a waste of time.
pontifier 5y ago
Fusion is on my plate too. I've got a design that I really need to test, an I've finally got the funds to begin construction. My method uses much lower magnetic fields that could be provided by permanent magnets, but should allow containment times on the order of weeks for small quantities of D-D fuel. I have more information at http://www.DDproFusion.com http://www.DDproFusion.com
- rpmisms 5y ago
  I love backyard science like this. No offense intended at all, but it's always heartening to see the Davids fighting the Goliaths.
- dmix 5y ago
  Looks like the video on your site is not working. At least from my region.
marsven_422 5y ago
Fusion is a distraction we can not afford, it creates the same low level waste as fission and we have plenty of fissionable material available. Massive international expansion of fission energy is needed for humanity to prosper.
m3at 5y ago
A bit off-topic but it feel like the right time to ask, does anyone recommend some video or even book to understand the fusion space better as a non-physicist?
HPMOR 5y ago
Honestly, fission has been the solution for the past 70 years. We, as a society, have just failed to implement it.
spoonjim 5y ago
MIT is also the origin of Transatomic Power which went belly up after they discovered that an early math mistake meant that their whole plan was bunkus, so evaluate this on its own merits rather than assigning any halo points from the MIT name.
oseityphelysiol 5y ago
Question from a layman: how will the energy from a fusion reactor be extracted and converted into electrical energy? As far as I understand, the plasma inside a tokamak is isolated from the surroundings by the use of very powerful magnets. I assume in a reactor that is supposed to generate electricity there would be some interface between the plasma and some kind of heat exchanger that would generate steam and turn gas turbines?
- jokteur 5y ago
  Neutrons that escape the tokamak arrive in a lithium mantle around the reactor, which produces helium and some heat. The heat is extracted from the lithium mantle, and then you have a conventional gas turbine. This is what I remember from memory, I would need to fact check that.
- tsimionescu 5y ago
  Yup, plain old heating water to make steam to turn a turbine.
pjmanroe 5y ago
I just read an article about this tonight on Sciencex.com I believe. It was impressive.
pjmanroe 5y ago
I just read an article about this tonight on Sciencex.com I believe it was. It was impressive. It reached 20 teslas in their test.
pjmanroe 5y ago
I just read this article tonight on Sciencex.com or .org. It was quite impressive. They reached 20 teslas in their test.
pjmanroe 5y ago
I read an article about this tonight on ScienceX.com or .org. It was quite impressive. They reached 20 teslas in their test.
phtrivier 5y ago
I hope the researchers behind this are proud. And I hope the marketers pretending they'll have a commercial plant by 2025 are ashamed.
deleted 5y ago
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ghego1 5y ago
From a economical/political point of view I find very interesting and promising that CFS is participated, amongst others, by one of the largest oil company in the world (ENI), which signal a real effort to move away, or at least strongly differentiate, from fossil fuels.
Mizza 5y ago
Are there other cool things we can do with this magnet tech? For instance, can I build a railgun to shoot things into orbit?
joelthelion 5y ago
Could these be used to build MRI machines?
nickik 5y ago
As a society we have failed to really use fission. Fission does basically everything fusion promises to do. Fission has a absurdly high energy density, the step from oil to fission is far more relevant then the step from fission to fusion. Fusion would mean basically no fuel cost, but thorium is already a waste product and even uranium fuel is a tiny part of any fission plant. Some people seem to believe the fusion is inherently prove against weapons, but this is equally not really true. If you had a working fission plant there would be ways to use it to get what you want to make a weapon. There are some places you might want fusion, mainly in space travel but even there we are not anywhere even close to where we could get to with fission. Open gas nuclear thermal rockets anybody? In sum, I'm not against this reseach but its not a way to solve our problems anytime soon. Fission you could get to run with 60s tech and amazing reactors could be designed within decades and often with comparatively small teams in the 60-80s and somehow we haven't managed to make it competitive. Fusion looks to be far more complex to build in every possible way. How this will be cheaper is questionable to me.
sc0ttyd 5y ago
The claim is that they have reached "a field strength of 20 tesla, the most powerful magnetic field of its kind ever created on Earth" Haven't Tokamak Energy in the UK done better than this already back in 2019 with their 24T magnet based on similar HTS tape technology? https://www.tokamakenergy.co.uk/tokamak-energy-exceeds-target-of-20-tesla-with-hts-magnets/ https://www.tokamakenergy.co.uk/tokamak-energy-exceeds-targe...
rkangel 5y ago
It's nice to see another promising avenue. The Wendelstein 7-X (a Stellerator) design is the other one that I'm particularly interested in. I believe it met its initial goals and is now in a multi-year refit before attempting continuous operation.
bawana 5y ago
If you compress something so much that its nuclei want to fuse, it must become very dense. At the core of this compression, density is intense. Unlike a thermonuclear weapon where the compression is transient, there is no release from this nuclear vise. Pressures would radically rise increasing compression even further. Would the gravitational field in the vicinity of the center of this be equally intense? Could black holes on the order of the Planck scale be created? Would such a 'Planck hole' start a chain reaction of gravitational collapse, eventually growing to consume our solar system?
lambdatronics 5y ago
Fusion scientist here (no connection with MIT/CFS). This is in fact a very big deal. One of the chief complaints about fusion energy is the low power density (for ITER-like tokamak <<1MW/m^3, vs ~ 100MW/m^3 for a LWR fission core). The low power density is the primary reason that ITER is as large (and hence expensive) as it is. Fusion power density scales like B^4. So if CFS can get 2x the magnetic field, then they can make the plasma volume 16x smaller, which might equate to big savings in cost and construction time. (It doesn't make sense to go much smaller than their ARC reactor design though -- the plasma already takes up only a fraction of the volume of the core at that scale, so compressing the plasma further doesn't improve the power density. If you can increase the field even more, which REBCO seems to allow, then you would rather just pack more power into a device about the size of ARC. So don't expect to put one of these on your DeLorean.) There are definitely other challenges/limitations. For one, this approach increases the heat flux that the inner wall of the reactor will have to survive. The localized heat flux of the exhaust stream is expected to rival the heat flux of re-entry from orbit (20 MW/m^2) and could be as high as the power flux from the surface of the sun (~60MW/m^2). 20MW/m^2 is on the hairy edge of what's possible with today's technology, and that's without all the complications of neutron damage, plasma bombardment, etc. The current thinking is to spike the outer layer of the plasma with neon or nitrogen, to radiate most of the power as photons, but there are limitations & risks to that idea as well. Commonwealth's plan for SPARC (last I heard) was to oscillate the exhaust stream back & forth across the absorber plate to reduce the average heat flux. The nuclear engineering side of fusion has been underfunded for a long time, so there's much that needs to be done on that front, in terms of demonstrating that the breeding of tritium from lithium can be done efficiently & without too much losses. Also, we should be developing better structural materials that can withstand neutron damage & not become (as) radioactive. It's still very much an open question as to whether fusion could be made economical, even though it seems like it should be technically possible.
shsbdncudx 5y ago
These are starting to sound like UFO pics. They’re always distant point of light.
RandyGoldy 5y ago
Oh, it sounds quite impressive. I want my project to achieve major advances as well, even though it's not really similar to fusion energy. Because of that, I decided to use the safety meeting checklist from https://fluix.io/safety-toolbox-talk-workflow https://fluix.io/safety-toolbox-talk-workflow , and I hope it'll be beneficial for my employees because I think the problem is in lack of their knowledge.

915 points by klintcho 5y ago

dfdz 5y ago

The thumbnail of the youtube video made me laugh Smaller. Smarter. Sooner. 2018 Currently 2021 where is my fusion energy? But this time must be different, after this advance we are only a few years away from fusion energy?

bwestergard 5y ago
They seem to have made two claims. First, that they have a qualitatively different design that requires a significantly stronger magnetic field. Second, that they could build a magnet that produces such a field. They are now claiming to have done the latter. Are you skeptical of the new design? Or do you think it does not represent as significant a departure from earlier designs as they claim?
ChrisMarshallNY 5y ago
The running joke has always been that “Fusion is 20 years away,” and has been, for the last 50 years. I really want this to work. I am a bit concerned, with how “the old guard” will react, once we have successful, productive, fusion. I foresee an astroturf NIMBY campaign against construction of fusion plants.
- soperj 5y ago
  It wasn't a joke, it was always based on an adequate level of funding. Everything is always off in the future if it never gets funded.
  - JackFr 5y ago
    Ah yes, and how much money? The answer always seems to be “More”.
    - MauranKilom 5y ago
      Please consult this graphic from 1976 if you are actually interested in the answer. https://i.imgur.com/3vYLQmm.png https://i.imgur.com/3vYLQmm.png
      - drdeca 5y ago
        Could you clarify how to read this chart? The y axis is, funding given different plans? Or.. I got the impression that this is meant to depict a relationship between when practical fusion would be developed and how much funding it receives, but I don’t see how to get that from the chart. Also, not sure why imgur has that image marked as adult content.
        MauranKilom 5y ago
        These are projections made in 1976. They can be read as different project plans made at that time for different amounts of funding. For example, "if we follow the blue plan, it would require 9 billion (2012) US dollars of funding in 1982 (etc.) and we would achieve fusion by 1990." The 1976 projection was that, assuming funding was kept at the level of 1976 (~1 billion a year), fusion would not be achieved in the foreseeable future. It further shows that actual funding has been below that level. In short: Yes, getting fusion off the ground sooner would have required more money. Not "always more", but more than "we project no success" levels.
        pfdietz 5y ago
        Those plans would not have worked, though. They were for programs that assumed tokamaks worked better than they actually do. And by the 1980s it was realized (Lidsky; Pfirsch and Schmitter) that heat transfer limits would make any tokamak power plant unattractive.
    - apendleton 5y ago
      I mean, yes, obviously if the criticism is that they're getting too little money, clearly they want more. Some technologies are fundamentally expensive to develop (the Apollo program, the Manhattan project, etc.). That doesn't mean the people saying so are automatically charlatans, especially given that they've never gotten what they've asked for -- it's not like some bomber development project where they get what they want and then keep coming back for more. The relatively paltry amounts the US has been devoting to fusion energy research are lower than any of the scenarios laid out in a 1976 DOE planning document[1] about what it would take to achieve fusion power, and lower even than just continuing at 1970s levels (a plan they labeled in that document as "fusion never"). [1] https://books.google.com/books?id=KSA_AAAAQBAJ&lpg=PA234&ots=vl9dP06svu&dq=%22possible%20paths%20to%20a%20reactor%20from%201976%22&pg=PA234#v=onepage&q&f=false https://books.google.com/books?id=KSA_AAAAQBAJ&lpg=PA234&ots...
- phicoh 5y ago
  At the moment it is very far for clear that fusion will be cost effective. The article says this about the fuel of fusion: "The fuel used to create fusion energy comes from water, and “the Earth is full of water — it’s a nearly unlimited resource. [...]" They forgot to say that it is not the H2O that comes out of your tap. The earth is especially not full of tritium.
  - apendleton 5y ago
    The plan is for them to breed their own tritium, though, so the consumables coming in the front door would just be deuterium and lithium, both of which (while less common than tap water) are not rare.
    - eropple 5y ago
      My understanding (and I am a layman) is that lithium isn't that accessibly common on Earth, and that we're doing a bang-up job of using as much of it as we can get our hands on already. Are there practical methods of extracting less accessible lithium that don't themselves have nasty side effects?
      - apendleton 5y ago
        Yeah, there have been rumblings about recovering it from seawater: https://electrek.co/2021/06/04/scientists-have-cost-effectively-harvested-lithium-from-seawater/ https://electrek.co/2021/06/04/scientists-have-cost-effectiv...
      - dodobirdlord 5y ago
        The amount of lithium required for these purposes is absolutely trivial.
  - rory 5y ago
    The fuel for fission comes from rocks. The Earth is full of rocks!
    - 5y ago
- Krasnol 5y ago
  You don't need an astroturf. Nuclear ruined it's own reputation for generations though hopeful not as long as they'll have to care for the waste we already have.
  - UnFleshedOne 5y ago
    What ruined nuclear reputation is environmentalists who don't actually care for environment.
    - ncmncm 5y ago
      What ruined nuclear's reputation is corruption, and being the most expensive choice. (Although coal will end up overwhelmingly more costly, in the end!) Would it be so expensive without corruption? Who can say? Corruption is wired into the process. We are purely lucky that, for structural reasons, corruption is minimal on solar and wind projects. Probably this is because what it ought to cost is readily visible from the outset. There just isn't enough fat to attract graft.
      - UnFleshedOne 5y ago
        Yeah, most expensive choice, unless you count externalities of coal.
    - Krasnol 5y ago
      Parroting Shellenberger will never make you look like a serious participant in this discussion.
      - UnFleshedOne 5y ago
        Haven't read his books, I must have gotten his ideas by osmosis. Now reading criticism of the books on his wiki page, I think his critics are not concerned with environment any further than it aids their real case if the quote below is a representative sample: "criticizing [The Death of Environmentalism: Global Warming in a Post-Environmental World] for demanding increased technological innovation rather than addressing the systemic concerns of people of color."
- AnimalMuppet 5y ago
  Per a comment by nielsbot, they're saying 2025. So, four years away, not 20. That's progress...
  - ncmncm 5y ago
    That is production of hot neutrons, not electrical power. Actual electrical power is still decades away... or would be if anybody bothered to try building it. Cost-effective electrical power from Tokamak is never. FRC, though, maybe. But you would have to have people actually working on that.
- MisterBastahrd 5y ago
  Fusion is the Linux Desktop of energy projects.
  - TheGoddessInari 5y ago
    Will fusion also occur then due to the mishandling of Windows 11?
- nixass 5y ago
  "Fusion is always 50 years away" for a reason https://www.reddit.com/r/Futurology/comments/5gi9yh/fusion_is_always_50_years_away_for_a_reason/ https://www.reddit.com/r/Futurology/comments/5gi9yh/fusion_i...
  - pfdietz 5y ago
    With respect to that graph: tokamaks turned out to not work nearly as well as the plans embodied there assumed (and because engineering obstacles were not sufficiently publicly acknowledged at the time). If funding has not been as high as hoped, it's because stakeholders don't really exist for fusion. The utilities have never thought much of it.
- ncmncm 5y ago
  There will be no need for NIMBY: fusion power is necessarily 100x+ more costly than solar + storage. The only real open question is how long the gravy train will run before the plug is pulled. F-35 and SLS have demonstrated that with careful management, that can be longer than anyone could have believed.
baking 5y ago
The company was founded in 2018. At the time they promised to demo this magnet during the Summer of 2021. What is the issue? The goal is to get fusion power om the grid in the 2030's and scale up in the 2040's. Stop moving the goalposts.

criticaltinker 5y ago

The advances enable a magnetic field strength that would otherwise require 40x more volume using conventional technology - doesn’t the reduced volume imply the plasma temperature would also increase significantly? Or is the magnetic field strong enough to protect the walls of the chamber?

tppiotrowski 5y ago
My understanding is that the volume of the magnet is smaller and thus the entire reactor size goes down significantly leading to lower cost. ITER was designed to use weaker electromagnets and therefore needs a massive building and tons of cranes and a massive budget.
- pfdietz 5y ago
  The ARC reactor design has 10x the volumetric power density of ITER. Unfortunately, the ARC design also had 40x worse power density than a PWR primary reactor vessel.
  - apendleton 5y ago
    Is that the right metric? You wouldn't need to build a huge containment structure around it like you would for a PWR, so I'd imagine the power density of the plant as a whole wouldn't be anywhere near 40x worse. Why focus just on the primary reactor vessel?
    - pfdietz 5y ago
      Because the rest of the power plant will be similar (or also worse for fusion; consider the tritium handling facility or the robotic equipment for maintaining the fusion reactor). You would need a confinement structure, just to keep the tritium in (which will leak all over even in normal operation). So if you swap out a cheap PWR reactor for a much larger, and hence much more expensive, fusion reactor, you get a power plant that costs more than a fission power plant. Viewed another way: if you could make a fission reactor with a power density as low as ARC, it would have so much thermal inertia that meltdowns would be essentially impossible. You should then ask why such fission reactors are not built.

shmageggy 5y ago

These university press releases are always very positively framed. This one makes the new magnet seem incredibly promising and fusion seem like almost an inevitability now, but decades of failure have us conditioned for skepticism. What's the catch this time?

stormbrew 5y ago
I'm not sure it's possible for "lay people" (of which I am one) to recognize the difference between a very slow success and "decades of failure". Very little is invested into fusion power as a project, overall. So advancements seem to come when outside influences cause breakthroughs. I wonder how different the world would have been if it had for whatever reason been easier to produce fusion power than a fusion bomb. Military investment into the bomb would have probably pushed things forward a lot quicker. As is, the US military built thermonuclear bombs very quickly and then the appetite for advancement just dried up.
- fshbbdssbbgdd 5y ago
  You could say that military investment into fusion and fission bombs was groundwork for everything done since. On the other hand, the fact that nuclear power started with bombs probably contributed to it falling out of favor and being regulated to irrelevance (even though hydrocarbons have been responsible for a lot more deaths and environmental damage).
phkahler 5y ago
>> What's the catch this time? There are a bunch of issues still to be resolved. Higher magnet strength is/was just one of many.
- ncmncm 5y ago
  That the most expensive parts of the plant would be quickly destroyed by neutron irradiation is another. That it would cost overwhelmingly more than solar+storage is what will ultimately kill it. Someday. Many more $B will be spent first.

xqcgrek2 5y ago

Ah, a university press release. Nah.

sdeyerle 5y ago

In the original proposal for the ARC reactor, they were proposing making the magnet separable so the top and bottom of the reactor could be separated and the vacuum vessel removed. (See pg. 5 of https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja032/15ja032_full.pdf https://library.psfc.mit.edu/catalog/reports/2010/15ja/15ja0...) It doesn't look like they are targeting that here. Does anyone know if that is ARC (not SPARC) specific, or if that has been abandoned?

nielsbot 5y ago
The article says this is from an "MIT-CFS collaboration" which is "on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. That demonstration device, called SPARC, is targeted for completion in 2025." So, sounds like it's for SPARC.
- sdeyerle 5y ago
  Yeah, they are definitely building SPARC. I had just been under the impression they were trying to do the separable magnets in SPARC, and was curious if I misunderstood their plan or if their plan had changed.
  - nielsbot 5y ago
    Yeah--I misread your question. :)
deleted 5y ago
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ncmncm 5y ago
Since there is no actual use planned for any power released in this gadget, no maintenance will be performed. When they finish playing, they scrap it, pocket the money, and go their separate ways. No commercial reactor will ever be built, so this is just for showing off. The only real good to come from these efforts is employment of plasma fluid physicists. I just hope non-military work can be found for them when this stuff fizzles. Solar Physics is fascinating and important, but has limited budget.

Seanambers 5y ago

If anyone have not seen it i recommend this video as a primer for fusion technology, it's from MIT. https://www.youtube.com/watch?v=L0KuAx1COEk https://www.youtube.com/watch?v=L0KuAx1COEk The video thouches upon magnetic fields and its relevance at this time mark ; https://youtu.be/L0KuAx1COEk?t=2880 https://youtu.be/L0KuAx1COEk?t=2880

mzs 5y ago

SPARC yttrium barium copper oxide (YBCO) high temp (10-70K) superconducting magnets

jcfrei 5y ago

Lots of negative comments in this thread. I've been following CFS for a few years now and I honestly believe this is an historic event - probably the beginning of the "fusion age".

phscguy 5y ago
Yeah, any positive news on fusion progress and there always seems to be the same set of comments appear that are overwhelmingly critical of fusion development. Fusion is not well funded and imo has been let down by mismanagement of ITER, and despite this keeps making progress. I feel that fusion is one of humanity's best shots at actively reversing climate change, and it is disheartening to see such widespread pessimism about it. Yeah it's hard. There are huge hurdles in making it economicly viable, but if we can go from first powered flight to the moon in 70 years, and put billions of transistors on a chip in 50, then maybe we can get fusion going. It's clearly possible.
- UnFleshedOne 5y ago
  There is a species of environmentalism that would consider successful fusion or similar high tech mega scale energy source actually detrimental because you can't build one in your hippy community using old tractor parts and alternative ways of knowing. Environmentally clean energy source is not enough, it needs to be ideologically pure as well.
  - pfdietz 5y ago
    This is projection. The irrationality is thinking that fusion is something desirable. I suspect this follows from exposure to fusion reactors as a trope in SF stories. From a hard nosed engineering point of view fusion is just terrible.
    - sprafa 5y ago
      Please tell me how it’s terrible, Mr Hard Nosed Engineer ?

nielsbot 5y ago

Update: They have a press release on their website https://cfs.energy/news-and-media/cfs-commercial-fusion-power-with-hts-magnet https://cfs.energy/news-and-media/cfs-commercial-fusion-powe... In case others are wondering, looks like this is for SPARC. FTA: This "MIT-CFS collaboration...on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes. That demonstration device, called SPARC, is targeted for completion in 2025." CFS: https://cfs.energy/technology https://cfs.energy/technology (edit: clarification)

noobermin 5y ago

University press releases need not be peer reviewed so they can get close to saying things that would offend other scientists and get away with it. The key phrase in "the most powerful magnetic field of its kind ever created on Earth" is "of its kind." Creating a many telsa magnetic field has been done in other experiments like with lasers[0], only they are physically smaller in size and last for nanoseconds, it's just of this size, stability and with the high temperature superconductors that makes it special. If the claim is just the magnitude of the field they've already been beat. [0] https://www.nature.com/articles/s41467-017-02641-7 https://www.nature.com/articles/s41467-017-02641-7 Just as a note, the max B field here is 600T

zardo 5y ago
I think "it's kind" refers specifically to a magnet for plasma containment. As this doesn't set the record for a REBCO magnet. https://nationalmaglab.org/news-events/news/lbc-project-world-record-magnetic-field https://nationalmaglab.org/news-events/news/lbc-project-worl...

freeopinion 5y ago

Let me know when the advance comes from Elizabethtown Community and Technical College. That would probably be affordable to put in production.

FredPret 5y ago

It's now only twenty years away!

dfdx 5y ago

Plenty of skepticism in these comments. I've been following CFS for a while and can present a point of view for why this time might be different. Fusion energy was actually making rapid progress in the latter half of the twentieth century, going from almost no power output in the fifties and sixties to a power output equal to 67% of input power with the JET reactor in 1997. By the eighties there was plenty of experimental evidence to describe the relationships between tokamak parameters and power output. Particularly that the gain is proportional to the radius to the power of 1.3 and the magnetic field cubed. The main caveat to this relationship was that we only had magnets that would go up to 5.5 Tesla, which implied we needed a tokamak radius of 6 meters or so in order to produce net energy. Well that 6 meter tokamak was designed in the eighties and is currently under construction. ITER, being so large, costs tens of billions of dollars and requires international collaboration; the size of the project has led to huge budget overruns and long delays. Recently however, there have been significant advances in high-temperature super conductors that can produce magnetic fields large enough that we (theoretically) only need a tokamak with a major radius of about 1.5 meters to produce net gain. This is where SPARC (the tokamak being built by the company in the article) comes in. The general idea is that since we have stronger magnets now, we can make a smaller, and therefore cheaper tokamak quickly. Small tokamaks do have downsides, namely that the heat flux through the walls of the device is so large that it will damage the tokamak. There have been breakthroughs with various divertor designs that can mitigate this, but to the best of my knowledge I'm not sure that CFS has specified their divertor configuration. This was just a short summary of the presentation by Dennis Whyte given here [0]. I do not work in the fusion community. [0] https://www.youtube.com/watch?v=KkpqA8yG9T4 https://www.youtube.com/watch?v=KkpqA8yG9T4

zetalyrae 5y ago
I've always wondered: why exactly is ITER so expensive, and slow? Is the engineering required at such a standard that it should takes decades of planning and construction and tens of billions of dollars? The timeline is so dilated (started in 1988, first plasma planned for 2025!) it feels like the kind of project that's expected to be cancelled from the start. It just doesn't strike me as obvious that reducing the major radius by a few meters would have such a huge impact on cost/timelines.

TrainedMonkey 5y ago

This is exciting. Magnetic field strength is a key component for enabling magnetic confinement fusion. This is because energy gain and power density scales to the 3rd and 4th power with magnetic field strength but only ~linearly with reactor size. See following equations for more details: https://youtu.be/xJ2h3vbOag4?t=306 https://youtu.be/xJ2h3vbOag4?t=306 So, why is this particular announcement exciting? There are 3 factors: 1. This is a high temperature superconductor. I can't find any references, but as far as I remember the substrate they are using needs to be cooled to (WRONG, it was cooled to 20degK, see reply by MauranKilom) 60-70 degK to achieve super conductivity. Compare to magnets used in ITER which need to be cooled to 4degK. This is the difference between using relatively cheap liquid nitrogen vs liquid helium. 2. Field strength of 20 Tesla is significantly higher than 13 Tesla used in ITER. Given that magnetic confinement fusion scales significantly better with field strength vs reactor size, this will enable much smaller reactor to be power positive. See following links for more details on ITERs magnets: https://www.newscientist.com/article/2280763-worlds-most-powerful-magnet-being-shipped-to-iter-fusion-reactor/ https://www.newscientist.com/article/2280763-worlds-most-pow... https://www.iter.org/newsline/-/2700 https://www.iter.org/newsline/-/2700 3. Finally, the magnet was assembled from 16 identical subassemblies, each of which used mass manufactured magnetic tape. This is significantly cheaper and more scalable than custom magnet design/manufacturing used by ITER. The kicker is how 3 of the factors above interact with the cost of the project. Stronger magnets allow smaller viable reactors. High temperature superconductors + smaller reactors allow for a much simpler and smaller cooling system. Smaller reactors + scalable magnet design further drives down the cost. Finally, cost of state of art mega projects scales somewhere between 3rd and 4th power with the size of the device. Combining all of the above factors, SPARC should be here significantly sooner than ITER and cost a tiny fraction (I would guesstimate that fraction to be between 1/100 and 1/10,000). edit: typos + looked at the cost of ITER and refined my cost fraction guesstimate + corrected some stuff based on the reply by MauranKilom.

MauranKilom 5y ago
Appreciate the rundown of why this is important! > This is because energy gain and power density scale exponentially with magnetic field strength but only linearly with reactor size Nit: It scales polynomially, not exponentially. Specifically (according to those formulas) energy gain scales with the cube of field strength and power density with the fourth power. Still massive scaling indeed, but exponentially would be something else. > as far as I remember the substrate they are using needs to be cooled to 60-70 degK to achieve super conductivity The video in the article shows 20 K. Could of course be that higher temperature is feasible and they just played it safe (or the video is wrong).

john_yaya 5y ago

The magnets are a problem to solve, but not the biggest problem by far. Solve for neutron embrittlement of the reactor parts, and then you’ll start to have some credibility.

NiceWayToDoIT 5y ago

I remembered that in 2018 Japanese team manage 1200 T peak power. http://www.sci-news.com/physics/strongest-magnetic-field-achieved-indoors-06420.html http://www.sci-news.com/physics/strongest-magnetic-field-ach... In comparison, 20T does not look much, but again it is, I wonder with the Japanese technique what is the highest continuous magnetic field.

uj8efdjkfdshf 5y ago
These high magnetic fields are generated using flux compression[0], in which the incompressibility of magnetic field lines means that compressing the coils generating the magnetic fields will increase the strength of the resultant magnetic field. However, the implosion process permanently destroys the magnet, which makes it highly unsuitable for continuous use and certainly shouldn't be used anywhere near your fusion reactor. [0] https://en.wikipedia.org/wiki/Explosively_pumped_flux_compression_generator https://en.wikipedia.org/wiki/Explosively_pumped_flux_compre...
pfdietz 5y ago
1200 T has a magnetic pressure of about 5.7 megabars (about 20x the detonation pressure of high explosives). Such high fields can only be achieved very briefly in devices that explosively disassemble.

sbierwagen 5y ago

Every mass-media article on fusion seems obliged to use "the fuel comes from water" line. I wonder if a "just says in mice" style harassment campaign would get journalists to stop saying this.

ncmncm 5y ago
Journalists quote promoters. When something has no reasonable prospect of ever producing, promoters resort to lying. Journalists are not responsible for it, although experience should make them less credulous. But pie in the sky sells better than skepticism.
rpmisms 5y ago
The journalists are saying that because the PR people tell them that. If I were doing PR for a fusion project, I'd sell that aspect hard—it's technically true, and sounds great.

fnord77 5y ago

so what is the most feasible approach? NIF's inertial containment or mini-tokamak?

kgarten 5y ago

Better title: Startup builds strong magnet that might be useful for a fusion plant.

pcj-github 5y ago

If we had "an inexhaustible, carbon-free source of energy that you can deploy anywhere and at any time" we'd wreck the planet faster than we already are... I guess at least a few could escape though.

maccam94 5y ago
I'm curious whether we could cool the planet by pulling CO2 out of the air with scrubbers powered by fusion reactors, or if their heat output would cancel it out. Removing the CO2 would have the benefit of being an exponential thermal decrease (the planet gets less hot from the sun each day), and heat output from fusion plants should scale linearly with the rate at which the CO2 scrubbers run, so it's possible the scaling properties would work out...
- sprafa 5y ago
  Unfortunately I predict that when we “stop” global warming will likely be when we stop changing the climate (at least in that way). This is because a lot of rich countries seem to me to be well placed to benefit partially from global climate change at the moment, at least within the 1-2C range. Changing the climate past that point is likely to be controversial, since the countries who now benefit from the situation will likely not want to give those newfound advantages away. I would think of it a lot as the end result of a war - the borders are defined by where the armies stopped ie the division of Europe and Asia after ww2. After climate change I expect whoever has benefitted from it to defend their position and reject any further alterations!
- ncmncm 5y ago
  Since power from a fusion plant would cost 100x+ what solar and wind cost, no. But every cent diverted to fusion from solar brings climate disaster closer.
  - gfodor 5y ago
    Do you have a reason to believe capital deployed to fusion would have been deployed to solar? And if so, why do you think it would make a difference, given the market feedback loop going on with solar driving down costs? Edit: also, your comments seem to be incredibly negative on fusion, would you mind disclosing if you have any solar or wind connected conflicts of interest?

cletus 5y ago

I've long been skeptical of ITER making any sense given its insane cost. I mean even it succeeds, then what? Here's the truth: there's no such thing as free energy. Even if the fuel is so abundant it's actually or effectively free (eg deuterium), the energy isn't. Say it takes $50B to build a plant that produces 1GW of power, which I'll estimate at about 7TWh/year based on [1]. Let's also say it has a lifespan of 40 years and an annual maintenance cost of $1B going to up to $2B in the last 10 years. So that's 40 years for 280TWh at a cost of $100B, which equates to $0.35/kWh if my math is correct. I realize ITER isn't a commercial power generation project. My point is that people need to stop getting hung up on the fuel being "free". The lifetime cost of the plant can still make it completely economically unviable. Second, the big weakness of any fusion design is neutrons. The problem people tend to focus on is that neutrons destroy your (very expensive) containment vessel with (one of my favourite terms) "neutron embrittlement". As an aside, hydrogen fusion also produces high speed helium nuclei, some of which tend to escape and this is a problem too because Helium nuclei are really small so can get in almost any material, which is a whole separate problem. But here's another factor with neutrons: energy loss. High speed neutrons represent energy lost by the system. To combat these problems we've looked for alternatives to hydrogen-hydrogen fusion, the holy grail of which is aneutronic fusion. The best candidate for that thus far seems to be Helium-3 fusion but He-3 is exceedingly rare on Earth. I really think we get caught up on the fact that this is how stars work but stars have a bunch of properties that power plants don't, namely they're really big and they burn their fuel really slowly (as a factor of their size), which is why they can last billions or even trillions of years. Loose neutrons aren't really an issue in a star and sheer size means gravity keeps the whole system contained in a way that magnets just can't (because neutrons ignore magnetic fields). So I hope they crack fusion but I remain skeptical. Personally I think the most likely future power source is space-based solar power generation. [1]: https://en.wikipedia.org/wiki/List_of_largest_power_stations https://en.wikipedia.org/wiki/List_of_largest_power_stations

sdenton4 5y ago
If only there were some way to capture and use all that power from the giant fusion reactor in the sky...
mLuby 5y ago

garbagecoder 5y ago

It just a decade away!!

JDDunn9 5y ago

Even if we can get fusion to work, it will never be economical. Just because the fuel (water) is free, that doesn't make the energy free. The fuel rods for fission power plants are already a rounding error in the cost of energy. It's the capital costs that dominate the equation, and fusion plants will be at least as expensive as fission, which is more expensive per KWh than solar. https://thebulletin.org/2017/04/fusion-reactors-not-what-theyre-cracked-up-to-be/ https://thebulletin.org/2017/04/fusion-reactors-not-what-the...

gfodor 5y ago
You’re citing an article from 2017 talking about a reactor design from 1988 in response to an article about novel fusion technology from 2021.
- loufe 5y ago
  I agree that the sourcing does seem off in JDDunn9's post but your comment doesn't invite further discussion much.

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derac 5y ago

SPARC is an amazing project. Congrats on this milestone! I am optimistic about SPARC and ARC. I'd love to hear legitimate critiques, though. I see a lot of negative comments on ITER, which is a very different situation. ITER will teach us a great deal btw, it isn't a waste of time.

pontifier 5y ago

Fusion is on my plate too. I've got a design that I really need to test, an I've finally got the funds to begin construction. My method uses much lower magnetic fields that could be provided by permanent magnets, but should allow containment times on the order of weeks for small quantities of D-D fuel. I have more information at http://www.DDproFusion.com http://www.DDproFusion.com

rpmisms 5y ago
I love backyard science like this. No offense intended at all, but it's always heartening to see the Davids fighting the Goliaths.
dmix 5y ago
Looks like the video on your site is not working. At least from my region.

marsven_422 5y ago

Fusion is a distraction we can not afford, it creates the same low level waste as fission and we have plenty of fissionable material available. Massive international expansion of fission energy is needed for humanity to prosper.

m3at 5y ago

A bit off-topic but it feel like the right time to ask, does anyone recommend some video or even book to understand the fusion space better as a non-physicist?

HPMOR 5y ago

Honestly, fission has been the solution for the past 70 years. We, as a society, have just failed to implement it.

spoonjim 5y ago

MIT is also the origin of Transatomic Power which went belly up after they discovered that an early math mistake meant that their whole plan was bunkus, so evaluate this on its own merits rather than assigning any halo points from the MIT name.

oseityphelysiol 5y ago

Question from a layman: how will the energy from a fusion reactor be extracted and converted into electrical energy? As far as I understand, the plasma inside a tokamak is isolated from the surroundings by the use of very powerful magnets. I assume in a reactor that is supposed to generate electricity there would be some interface between the plasma and some kind of heat exchanger that would generate steam and turn gas turbines?

jokteur 5y ago
Neutrons that escape the tokamak arrive in a lithium mantle around the reactor, which produces helium and some heat. The heat is extracted from the lithium mantle, and then you have a conventional gas turbine. This is what I remember from memory, I would need to fact check that.
tsimionescu 5y ago
Yup, plain old heating water to make steam to turn a turbine.

pjmanroe 5y ago

I just read an article about this tonight on Sciencex.com I believe. It was impressive.

pjmanroe 5y ago

I just read an article about this tonight on Sciencex.com I believe it was. It was impressive. It reached 20 teslas in their test.

pjmanroe 5y ago

I just read this article tonight on Sciencex.com or .org. It was quite impressive. They reached 20 teslas in their test.

pjmanroe 5y ago

I read an article about this tonight on ScienceX.com or .org. It was quite impressive. They reached 20 teslas in their test.

phtrivier 5y ago

I hope the researchers behind this are proud. And I hope the marketers pretending they'll have a commercial plant by 2025 are ashamed.

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ghego1 5y ago

From a economical/political point of view I find very interesting and promising that CFS is participated, amongst others, by one of the largest oil company in the world (ENI), which signal a real effort to move away, or at least strongly differentiate, from fossil fuels.

Mizza 5y ago

Are there other cool things we can do with this magnet tech? For instance, can I build a railgun to shoot things into orbit?

joelthelion 5y ago

Could these be used to build MRI machines?

nickik 5y ago

As a society we have failed to really use fission. Fission does basically everything fusion promises to do. Fission has a absurdly high energy density, the step from oil to fission is far more relevant then the step from fission to fusion. Fusion would mean basically no fuel cost, but thorium is already a waste product and even uranium fuel is a tiny part of any fission plant. Some people seem to believe the fusion is inherently prove against weapons, but this is equally not really true. If you had a working fission plant there would be ways to use it to get what you want to make a weapon. There are some places you might want fusion, mainly in space travel but even there we are not anywhere even close to where we could get to with fission. Open gas nuclear thermal rockets anybody? In sum, I'm not against this reseach but its not a way to solve our problems anytime soon. Fission you could get to run with 60s tech and amazing reactors could be designed within decades and often with comparatively small teams in the 60-80s and somehow we haven't managed to make it competitive. Fusion looks to be far more complex to build in every possible way. How this will be cheaper is questionable to me.

sc0ttyd 5y ago

The claim is that they have reached "a field strength of 20 tesla, the most powerful magnetic field of its kind ever created on Earth" Haven't Tokamak Energy in the UK done better than this already back in 2019 with their 24T magnet based on similar HTS tape technology? https://www.tokamakenergy.co.uk/tokamak-energy-exceeds-target-of-20-tesla-with-hts-magnets/ https://www.tokamakenergy.co.uk/tokamak-energy-exceeds-targe...

rkangel 5y ago

It's nice to see another promising avenue. The Wendelstein 7-X (a Stellerator) design is the other one that I'm particularly interested in. I believe it met its initial goals and is now in a multi-year refit before attempting continuous operation.

bawana 5y ago

If you compress something so much that its nuclei want to fuse, it must become very dense. At the core of this compression, density is intense. Unlike a thermonuclear weapon where the compression is transient, there is no release from this nuclear vise. Pressures would radically rise increasing compression even further. Would the gravitational field in the vicinity of the center of this be equally intense? Could black holes on the order of the Planck scale be created? Would such a 'Planck hole' start a chain reaction of gravitational collapse, eventually growing to consume our solar system?

lambdatronics 5y ago

Fusion scientist here (no connection with MIT/CFS). This is in fact a very big deal. One of the chief complaints about fusion energy is the low power density (for ITER-like tokamak <<1MW/m^3, vs ~ 100MW/m^3 for a LWR fission core). The low power density is the primary reason that ITER is as large (and hence expensive) as it is. Fusion power density scales like B^4. So if CFS can get 2x the magnetic field, then they can make the plasma volume 16x smaller, which might equate to big savings in cost and construction time. (It doesn't make sense to go much smaller than their ARC reactor design though -- the plasma already takes up only a fraction of the volume of the core at that scale, so compressing the plasma further doesn't improve the power density. If you can increase the field even more, which REBCO seems to allow, then you would rather just pack more power into a device about the size of ARC. So don't expect to put one of these on your DeLorean.) There are definitely other challenges/limitations. For one, this approach increases the heat flux that the inner wall of the reactor will have to survive. The localized heat flux of the exhaust stream is expected to rival the heat flux of re-entry from orbit (20 MW/m^2) and could be as high as the power flux from the surface of the sun (~60MW/m^2). 20MW/m^2 is on the hairy edge of what's possible with today's technology, and that's without all the complications of neutron damage, plasma bombardment, etc. The current thinking is to spike the outer layer of the plasma with neon or nitrogen, to radiate most of the power as photons, but there are limitations & risks to that idea as well. Commonwealth's plan for SPARC (last I heard) was to oscillate the exhaust stream back & forth across the absorber plate to reduce the average heat flux. The nuclear engineering side of fusion has been underfunded for a long time, so there's much that needs to be done on that front, in terms of demonstrating that the breeding of tritium from lithium can be done efficiently & without too much losses. Also, we should be developing better structural materials that can withstand neutron damage & not become (as) radioactive. It's still very much an open question as to whether fusion could be made economical, even though it seems like it should be technically possible.

shsbdncudx 5y ago

These are starting to sound like UFO pics. They’re always distant point of light.

RandyGoldy 5y ago

Oh, it sounds quite impressive. I want my project to achieve major advances as well, even though it's not really similar to fusion energy. Because of that, I decided to use the safety meeting checklist from https://fluix.io/safety-toolbox-talk-workflow https://fluix.io/safety-toolbox-talk-workflow , and I hope it'll be beneficial for my employees because I think the problem is in lack of their knowledge.