8 ms·

New records on Wendelstein 7-X

243 points by greesil 1y ago

saddat 1y ago
Some charts : https://youtu.be/ZOZ6p2o6O14 https://youtu.be/ZOZ6p2o6O14
tyiz 1y ago
[dead]
apples_oranges 1y ago
Looking at the picture, I wonder if complexity of these devices will significantly be reduced once it finally works. I assume a lot of the bells and whistles are needed to find the way, but once it's found..
- StevenWaterman 1y ago
  Your question reminds me of the image showing how SpaceX raptor motors evolved https://imgur.com/a/4w3q3lS https://imgur.com/a/4w3q3lS
  - pengaru 1y ago
    Is that an actual honest photo? The first two seem fully equipped including what seems to be shielded wiring harnesses. #3 looks totally devoid of any electronics. disclaimer: I don't follow this stuff at all. It just looks like a b.s. photo deliberately exaggerating how simplified #3 is vs. the others to this grease monkey.
    - jcims 1y ago
      Ready to rock(et) https://x.com/gwynne_shotwell/status/1821674726885924923?s=46 https://x.com/gwynne_shotwell/status/1821674726885924923?s=4...
    - mjamesaustin 1y ago
      IIRC not only did they remove many parts completely, but others have been integrated into the interior, which makes repair harder but will improve reliability since they are no longer exposed.
  - GMoromisato 1y ago
    To be fair, the reason the right-most Raptor looks so clean is because they moved all the piping (all the complexity) to inside the casing. And the reason they made the effort is because the casing protects the tubing from the heat of re-entry. Otherwise they'd have to waste mass on heat shielding. [Take a look at videos of Superheavy Booster returning back to the launch tower--the bottom engine sections starts to glow from the heat.] I don't think that applies to Stellarators, so there may not be an incentive to simplify it. [But what do I know; I'm just a simple programmer.]
    - lux44 1y ago
      > the bottom engine sections starts to glow from the heat It's fuel burning, not glow. Speed is too low for glowing; glow would start at the edge, not from deep inside the skirt etc.
  - ortusdux 1y ago
    I'm not keen on the idea of applying a 'keep subtracting things until it blows up' mentality to fusion reactors.
    - bhaak 1y ago
      The nice thing about fusion reactors is that they don’t blow up but just don’t work anymore.
      - soperj 1y ago
        they have fission reactors that have done that since the 60s (CANDU Reactor). They just don't help you produce nuclear bombs...
        greesil 1y ago
        I dunno dude, if you fuse tritium and deuterium it does make neutrons.
        philipkglass 1y ago
        CANDU has low intrinsic nuclear proliferation resistance. It can run on natural uranium, so it's easier to fuel than light water reactors which need enriched uranium, and its online fuel-swapping design means that it's easy to switch to low-burnup operation for generating weapons grade plutonium. Current CANDU power reactors have extensive monitoring to confirm that they are used peacefully, but if e.g. South Korea had a security crisis and decided to pursue a crash nuclear weapons program, world opinion be damned, its CANDU based reactors at Wolseong could be quickly reconfigured for weapons purposes: https://en.wikipedia.org/wiki/Wolseong_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Wolseong_Nuclear_Power_Plant
        perihelions 1y ago
        It's topical that India's nuclear weapons program was started up with a Canadian-supplied heavy water reactor (though not CANDU; a not-power-generating type). https://en.wikipedia.org/wiki/CIRUS_reactor https://en.wikipedia.org/wiki/CIRUS_reactor > "Canada stipulated, and the U.S. supply contract for the heavy water explicitly specified, that it only be used for peaceful purposes. Nonetheless, CIRUS produced some of India's initial weapons-grade plutonium stockpile,[6] as well as the plutonium for India's 1974 Pokhran-I (Codename Smiling Buddha) nuclear test, the country's first nuclear test.[7]"
  - idiotsecant 1y ago
    Raptor 3 really is quite an achievement. Good on them.
  - sheepscreek 1y ago
    Wow - beautiful. So there is hope! As someone unfamiliar with the challenges of mechanical engineering, I’ve often wondered at the complexity of fusion reactors. This picture puts a lot into perspective. Thanks for sharing!
    - api 1y ago
      Current fusion reactors are also studded with a ton of sensors and adjustments and injection ports and such that might not be present in a production reactor. They are experimental platforms, more like scientific instruments for studying the problem domain than production systems.
- LeifCarrotson 1y ago
  In my experience doing plumbing/hydraulics/pneumatics for industrial equipment, the first generation of a new product always looks way more complex than later versions. But I'm not sure they're actually more complex, they're often using a smaller variety of more flexible "industrial Lego" rather than custom, unique parts that are harder to extend or modify. Yeah, a single welded tube of the right diameter that necks down just so in that one spot to prevent cavitation, which has that sweeping multi-planar bend to just barely sneak through that obstruction, will look neat and tidy to a casual observer. Conversely, a stack of triclamp flanges, a straight length of pipe that shoots way out away from the guts of the equipment before it jogs sideways and down and back in with 90 degree couplings and gaskets and a manual shut-off valve and a pressure transmitter/flow meter and a "T" with a cap (just in case) and a sight glass looks like an awful mess. But I can build the latter in half an hour with parts we have on hand. And I'm not even a fitter, I'm an engineer! And when you do want to add something to it, I can do that in 5 minutes. After observing it function through the full regime of pressure and flow and viscosity parameters the equipment might have to deal with, I can maybe generate a print for the real plumbers to build the former dedicated-purpose component that sets all the constraints in stone (or rather, in welded stainless). That part will be unique and inflexible, embedding all the restrictions and history and test results and design decisions into a component that looks deceptively smooth to a layman's eyes. Is that simpler? I suppose it depends on your perspective.
  - jeffbee 1y ago
    W7-X looks insane because its configuration was discovered by a computer pursuing a numerical optimization. We don't have any sound reasons to believe the next one will be simpler.
    - krisoft 1y ago
      > We don't have any sound reasons to believe the next one will be simpler. Yes and no. I think you are right that the plasma shape is going to remain very complex. But that's not the only reason why W7-X looks complicated. It has a ton of diagnostics ports on the plasma vessel just for research. Most of those we can probably design out for a production version. So I would expect a production version of a stelarator to be simpler than W7-X, but still remain very complex.
- empath75 1y ago
  The real problem with fusion power is that even if they figure it out, it still won't be cost competitive with solar and wind. Economically all the cost of building a "boil some water and turn some turbines" plant is _already_ in the "boiling some water and turning some turbines" part of the generation, and even if the heat part of it was _free_, the rest of it would be too expensive to bother building a plant for it, compared to just building solar and wind generation and some better batteries.
  - JumpCrisscross 1y ago
    > real problem with fusion power is that even if they figure it out, it still won't be cost competitive with solar and wind This is difficult to say when comparing an emerging technology with an established technology in an emerging economy. Based on every historical prior, it would be surprising if there weren't diminishing returns to solar and wind. And I wouldn't underestimate the degree to which power is, in part, fashion. Today we value emissions. Tomorrow it may be preserving and expanding wild spaces. On a practical level, fusion research doesn't compete with solar and wind deployment. Pursuing both is optimal.
    - davrosthedalek 1y ago
      Additionally, the total amount of solar and wind is limited. Surely more than we need now, don't get me wrong, but how much more? Factor 2? 10? I could see a future that is extremely energy hungry, and not just because of AI.
      - JumpCrisscross 1y ago
        > the total amount of solar and wind is limited I'd be shocked if we max out on insolation before area we're willing to cover with solar panels and windmills.
    - Dr4kn 1y ago
      PV Panel production acts more like typical mass production and has therefore much higher cost benefits compared to every other way of producing power. For every other way of producing energy you need separate land for PV you don't. You can put them on rooftops, over parking lots or even vertical in a field. The last one increases the crop yield. Crops get less harsh sun, lose less water and the evaporation cools down the panels, which increases their production. Today we value costs of energy production and tomorrow we will to. Especially if it results in energy independence. You don't need to buy fuel for PV and wind. As with nuclear fuel only a few countries are probably going to manufacturing the fuel needed for fusion reactors. Producing enough of it and in a sufficient purity needs specialized facilities and they will only be profitable if they produce a lot of it.
- constantcrying 1y ago
  These reactors are build for research, so presumably they need to be more modular, have more measuring components and be more accessible for changes.
- vjvjvjvjghv 1y ago
  That's how it goes most of the time. First you have to make it work somehow, often in a very complex way. Once you have something that works, either you can strip away a lot or the components get commoditized and you can buy them in a nice package. A lot of our devices are super complex but you can build a device without much knowledge because the complexity is hidden away in nicely packaged components.
alpineman 1y ago
Old article, from June...don't get me excited
brohee 1y ago
Does it kill the idea of a tokamak as an energy production device? As in a stellarator proving the much more promising design...
- Lev1a 1y ago
  Not an expert on the topic by any means, but IIRC: - Those designs have been in parallel R&D for decades - Tokamaks are conceptually simpler, thus might be easier/faster/cheaper to make into viable installations - Stellarators are WAAAAAY more complex to design and build but AFAIU they would have the huge benefit of being able to sustain the plasma for way longer for the same "startup cost" of a cycle since the particles of the plasma are routed somewhat like they're on a mobius strip instead of a simple torus (which should make it easier to confine more particles for a longer time). I recall having read (several years ago) that the simulation technology of the 90's wasn't really up to the task of aiding in the design of those weird wavy magnets for Wendelstein 7-X, an unfortunate reality which delayed the project a lot.
- Miraste 1y ago
  I'm no expert, but from the full press release it appears this experiment is the first time they've even been competitive with tokamaks, and are still behind the latest (unpublished) tokamak results.
- cyberax 1y ago
  It'll be a question of manufacturing. A tokamak is a fairly simple torus, with at least some similar parts. Stellerators are freakishly complicated 3D structures that require submillimeter precision. So it might end up being cheaper to construct a larger tokamak.
- HarHarVeryFunny 1y ago
  Perhaps, unless you fall prey to the sunk cost fallacy and have already spent a bazillion dollars on generations of tokamaks!
- runxel 1y ago
  Both ideas are pretty old (50s) and in development for a long time. Both designs have their pros and cons. The biggest drawback of the Tokamak however is that it can only be pulsed... which is kind of dumb to actually generate and provide energy in the long run. You really want the Stellarator here, since there it is at least theoretically possible to run "for ever" (not entirely true, but long enough cycles to be used in a power plant). There are 2 podcast episodes with the guys who run Wendelstein here: http://www.alternativlos.org/51/ http://www.alternativlos.org/51/ (it's German tho)
wedn3sday 1y ago
I've always been somewhat partial to the stellarator design, I mean a big plasma donut is cool and all, but what if we twisted it around a whole bunch first!?
- cgannett 1y ago
  mmmm plasma cruller uhuhuhuhuhu -Homer Simpson
- HarHarVeryFunny 1y ago
  I think gravitational confinement is the way to go - it's the only operationally proven design! Gotta think big!
  - weregiraffe 1y ago
    No, it's not the only proven design. The other is a hydrogen bomb. Google project PACER.
    - HarHarVeryFunny 1y ago
      True - inertial confinement - also used by NIF (laser based). I guess I should have said continuous operation, although I do like the simplicity of Helion's system.
  - exe34 1y ago
    You only need one at that point!
  - ars 1y ago
    It has density issues though. If you had a piece of the sun the size of a huge power plant - like enormous, the power output would be too low to be useful.
    - grumbelbart 1y ago
      Mandatory: We should build it in space and beam the electricity back to earth using electromagnetic waves. We could collect those using solar cells. And then get rid of the plant and use the sun instead.
bradleyy 1y ago
In any future fusion power plant, a plasma with a high triple product must be maintained for long periods. I love vague terms like "long periods". Long compared to the Planck length? Geological time? Is the advertised 43 seconds almost there or "off by 17 orders of magnitude?"
- dmbche 1y ago
  I believe it's "for as long as the reactor is to be operating", and they contrast that with the previous longest times being less than 45 seconds.
  - Analemma_ 1y ago
    I thought the expectation was that actually-operating fusion plants would operate in pulses rather than continuously, but I could be misremembering.
    - smallerize 1y ago
      Toroidal reactors have to operate in pulses. Stellarators can be operated in steady-state (although sometimes they are pulsed to achieve higher energy).
      - rnhmjoj 1y ago
        Tokamaks can also be operated in steady-state, at least theoretically. The reason a tokamak is pulsed is due to the fact the toroidal current is driven inductively, so there is a limit to how long you can keep increasing the current in the central solenoid. However there are other methods, for example, neutral beam injection and electron cyclotron current drive. You can even exploit the bootstrap current (self-generated by collisional processes in the plasma) to obtain a near 100% non-inductive toroidal plasma (this is called "advanced tokamak" regime). Anyway, the older generation of devices was pulsed for engineering reasons (like non-superconducting coils getting too hot). The current generation of device is solving most of these and is limited by MHD instabilities alone (neoclassical tearing modes, mostly), if we can get active control mechanism working, then will be finally approach the long-pulse or steady-state regime.
tgtweak 1y ago
This article has zero quantifiable information in it aside from the duration... which has no context. Who's recordkeeping this stuff? What are the other results so far? What is the tipping point where it is net positive? how long does it need to sustain a net positive fusion reaction to produce sufficient power for grid consumption? Are there other losses (thermal generation inefficiencies) that make the target even farther than energy-in<energy-out?
- colechristensen 1y ago
  >What is the tipping point where it is net positive? There are several interesting net positive tipping points depending on where you draw the boundary that energy in and energy out cross. We're still in the earlier stages of net positive where the boundary is quite small and little consideration is being given to the part of the process where electrons get pushed around in a power grid.
- deleted 1y ago
  [deleted]
- tgtweak 1y ago
  Here is an actual article with some context - and a reality check that other experimental reactors in the past have sustained similar triple product for longer durations... https://www.ipp.mpg.de/5532945/w7x https://www.ipp.mpg.de/5532945/w7x
  - i_am_proteus 1y ago
    >The fact that W7-X results are on a par with JET is remarkable because JET had three times the plasma volume of Wendelstein 7-X. What's important here is that W 7-X is a stellarator, a different type of fusion reactor from almost all prior reactors (they are tokamaks), with a smaller volume than the co-record holder. That a stellarator gets these results with a much smaller fusion volume is promising for the performance of future larger stellarators, since fusion reactors typically become more efficient as they get larger.
    - 1y ago
cubefox 1y ago
The article links to the original source, which has more details: https://www.ipp.mpg.de/5532945/w7x https://www.ipp.mpg.de/5532945/w7x
chris_va 1y ago
A better link: https://www.ipp.mpg.de/5532945/w7x?c=5481737 https://www.ipp.mpg.de/5532945/w7x?c=5481737 (there is some irony in using the iter.org link for a stellarator announcement) 1.8GJ over 360 seconds, beta of 0.03
- perihelions 1y ago
  > "1.8GJ over 360 seconds" Not sure if this is contextually obvious to practitioners, but that figure is the "Energy turnover" / "is calculated as the product of injected heating power and plasma duration".
- greesil 1y ago
  The irony is delicious. Especially considering the total budget of it is $340 millions vs ITER's tens of billions.
  - WhereIsTheTruth 1y ago
    Their findings complement and help each other, there is no irony in there
    - greesil 1y ago
      Of course they can complement each other but ITER can still be an inefficient use of science funds at the same time.
  - Ey7NFZ3P0nzAe 1y ago
    To be fair, they might not be totally independent figures in the sense of, I would be surprised if the cheaper project did not benefit at all from the knowledge created by the larger project.
    - ygra 1y ago
      Help on either project actually flows both ways. If I remember correctly, Wendelstein 7-X provided experience and know-how regarding microwave heating and welding large plasma vessels. In the end they're scientists and engineers and don't seem to see the other project so much as competition than a way to learn more than just with one of them.
sheepscreek 1y ago
TL;DR - Looks dangerous, but is it? (open question) Can we quantify it or at least make it more tangible? God, this contraption appears to be the kind of thing I wouldn’t trust my life with. Every time I look at a fusion reactor, it seems far more dangerous than my hobby lab, failing to inspire any confidence. The numerous moving parts create an equal number of potential points of failure. In contrast, a nuclear reactor doesn’t have to contend with plasma gases hotter than the Sun, contained within an artificial bubble solely through the assistance of electromagnetic radiation. I’ve often tried to imagine the worst case scenario, but I am limited by my knowledge on the subject. What kind of damage can hot plasma at a few million degree C do? On one hand, the plasma is hotter than anything on earth created by mankind. Then I believe there’s also a significant number of wild neutrons shooting around which can cause havoc in their own right, if not contained. But on the other hand, unlike an uncontrolled chain reaction, without a source of heat, the whole operation shuts off by itself. I’m probably wrong about a few assumptions here but this is what I often find myself wondering.
- thinkcontext 1y ago
  That fusion reactions are so difficult to get started makes the reactors very safe because failure makes them stop. So, if you lose magnetic confinement the reaction stops. The reactor may be damaged but that's it. This is unlike fission reactors, where a failure causes reactivity to increase. That causes meltdown and the possibility of explosion and all the nasty radioactive contamination.
  - mathw 1y ago
    My understanding is that more recent fission reactor designs are done in such a way that they fail in ways which cause the reaction to diminish rather than build up further, which puts you in a better place than, say, Chernobyl. You still have a very hot very radioactive lump of death in the middle of your busted reactor when it's all done though, and that's definitely not fun. Fusion failure modes - in current designs anyway - are far more appealing to anybody who happens to be in the area at the time.
- Workaccount2 1y ago

243 points by greesil 1y ago

saddat 1y ago

Some charts : https://youtu.be/ZOZ6p2o6O14 https://youtu.be/ZOZ6p2o6O14

tyiz 1y ago

[dead]

apples_oranges 1y ago

Looking at the picture, I wonder if complexity of these devices will significantly be reduced once it finally works. I assume a lot of the bells and whistles are needed to find the way, but once it's found..

StevenWaterman 1y ago
Your question reminds me of the image showing how SpaceX raptor motors evolved https://imgur.com/a/4w3q3lS https://imgur.com/a/4w3q3lS
- pengaru 1y ago
  Is that an actual honest photo? The first two seem fully equipped including what seems to be shielded wiring harnesses. #3 looks totally devoid of any electronics. disclaimer: I don't follow this stuff at all. It just looks like a b.s. photo deliberately exaggerating how simplified #3 is vs. the others to this grease monkey.
  - jcims 1y ago
    Ready to rock(et) https://x.com/gwynne_shotwell/status/1821674726885924923?s=46 https://x.com/gwynne_shotwell/status/1821674726885924923?s=4...
  - mjamesaustin 1y ago
    IIRC not only did they remove many parts completely, but others have been integrated into the interior, which makes repair harder but will improve reliability since they are no longer exposed.
- GMoromisato 1y ago
  To be fair, the reason the right-most Raptor looks so clean is because they moved all the piping (all the complexity) to inside the casing. And the reason they made the effort is because the casing protects the tubing from the heat of re-entry. Otherwise they'd have to waste mass on heat shielding. [Take a look at videos of Superheavy Booster returning back to the launch tower--the bottom engine sections starts to glow from the heat.] I don't think that applies to Stellarators, so there may not be an incentive to simplify it. [But what do I know; I'm just a simple programmer.]
  - lux44 1y ago
    > the bottom engine sections starts to glow from the heat It's fuel burning, not glow. Speed is too low for glowing; glow would start at the edge, not from deep inside the skirt etc.
- ortusdux 1y ago
  I'm not keen on the idea of applying a 'keep subtracting things until it blows up' mentality to fusion reactors.
  - bhaak 1y ago
    The nice thing about fusion reactors is that they don’t blow up but just don’t work anymore.
    - soperj 1y ago
      they have fission reactors that have done that since the 60s (CANDU Reactor). They just don't help you produce nuclear bombs...
      - greesil 1y ago
        I dunno dude, if you fuse tritium and deuterium it does make neutrons.
      - philipkglass 1y ago
        CANDU has low intrinsic nuclear proliferation resistance. It can run on natural uranium, so it's easier to fuel than light water reactors which need enriched uranium, and its online fuel-swapping design means that it's easy to switch to low-burnup operation for generating weapons grade plutonium. Current CANDU power reactors have extensive monitoring to confirm that they are used peacefully, but if e.g. South Korea had a security crisis and decided to pursue a crash nuclear weapons program, world opinion be damned, its CANDU based reactors at Wolseong could be quickly reconfigured for weapons purposes: https://en.wikipedia.org/wiki/Wolseong_Nuclear_Power_Plant https://en.wikipedia.org/wiki/Wolseong_Nuclear_Power_Plant
        perihelions 1y ago
        It's topical that India's nuclear weapons program was started up with a Canadian-supplied heavy water reactor (though not CANDU; a not-power-generating type). https://en.wikipedia.org/wiki/CIRUS_reactor https://en.wikipedia.org/wiki/CIRUS_reactor > "Canada stipulated, and the U.S. supply contract for the heavy water explicitly specified, that it only be used for peaceful purposes. Nonetheless, CIRUS produced some of India's initial weapons-grade plutonium stockpile,[6] as well as the plutonium for India's 1974 Pokhran-I (Codename Smiling Buddha) nuclear test, the country's first nuclear test.[7]"
- idiotsecant 1y ago
  Raptor 3 really is quite an achievement. Good on them.
- sheepscreek 1y ago
  Wow - beautiful. So there is hope! As someone unfamiliar with the challenges of mechanical engineering, I’ve often wondered at the complexity of fusion reactors. This picture puts a lot into perspective. Thanks for sharing!
  - api 1y ago
    Current fusion reactors are also studded with a ton of sensors and adjustments and injection ports and such that might not be present in a production reactor. They are experimental platforms, more like scientific instruments for studying the problem domain than production systems.
LeifCarrotson 1y ago
In my experience doing plumbing/hydraulics/pneumatics for industrial equipment, the first generation of a new product always looks way more complex than later versions. But I'm not sure they're actually more complex, they're often using a smaller variety of more flexible "industrial Lego" rather than custom, unique parts that are harder to extend or modify. Yeah, a single welded tube of the right diameter that necks down just so in that one spot to prevent cavitation, which has that sweeping multi-planar bend to just barely sneak through that obstruction, will look neat and tidy to a casual observer. Conversely, a stack of triclamp flanges, a straight length of pipe that shoots way out away from the guts of the equipment before it jogs sideways and down and back in with 90 degree couplings and gaskets and a manual shut-off valve and a pressure transmitter/flow meter and a "T" with a cap (just in case) and a sight glass looks like an awful mess. But I can build the latter in half an hour with parts we have on hand. And I'm not even a fitter, I'm an engineer! And when you do want to add something to it, I can do that in 5 minutes. After observing it function through the full regime of pressure and flow and viscosity parameters the equipment might have to deal with, I can maybe generate a print for the real plumbers to build the former dedicated-purpose component that sets all the constraints in stone (or rather, in welded stainless). That part will be unique and inflexible, embedding all the restrictions and history and test results and design decisions into a component that looks deceptively smooth to a layman's eyes. Is that simpler? I suppose it depends on your perspective.
- jeffbee 1y ago
  W7-X looks insane because its configuration was discovered by a computer pursuing a numerical optimization. We don't have any sound reasons to believe the next one will be simpler.
  - krisoft 1y ago
    > We don't have any sound reasons to believe the next one will be simpler. Yes and no. I think you are right that the plasma shape is going to remain very complex. But that's not the only reason why W7-X looks complicated. It has a ton of diagnostics ports on the plasma vessel just for research. Most of those we can probably design out for a production version. So I would expect a production version of a stelarator to be simpler than W7-X, but still remain very complex.
empath75 1y ago
The real problem with fusion power is that even if they figure it out, it still won't be cost competitive with solar and wind. Economically all the cost of building a "boil some water and turn some turbines" plant is _already_ in the "boiling some water and turning some turbines" part of the generation, and even if the heat part of it was _free_, the rest of it would be too expensive to bother building a plant for it, compared to just building solar and wind generation and some better batteries.
- JumpCrisscross 1y ago
  > real problem with fusion power is that even if they figure it out, it still won't be cost competitive with solar and wind This is difficult to say when comparing an emerging technology with an established technology in an emerging economy. Based on every historical prior, it would be surprising if there weren't diminishing returns to solar and wind. And I wouldn't underestimate the degree to which power is, in part, fashion. Today we value emissions. Tomorrow it may be preserving and expanding wild spaces. On a practical level, fusion research doesn't compete with solar and wind deployment. Pursuing both is optimal.
  - davrosthedalek 1y ago
    Additionally, the total amount of solar and wind is limited. Surely more than we need now, don't get me wrong, but how much more? Factor 2? 10? I could see a future that is extremely energy hungry, and not just because of AI.
    - JumpCrisscross 1y ago
      > the total amount of solar and wind is limited I'd be shocked if we max out on insolation before area we're willing to cover with solar panels and windmills.
  - Dr4kn 1y ago
    PV Panel production acts more like typical mass production and has therefore much higher cost benefits compared to every other way of producing power. For every other way of producing energy you need separate land for PV you don't. You can put them on rooftops, over parking lots or even vertical in a field. The last one increases the crop yield. Crops get less harsh sun, lose less water and the evaporation cools down the panels, which increases their production. Today we value costs of energy production and tomorrow we will to. Especially if it results in energy independence. You don't need to buy fuel for PV and wind. As with nuclear fuel only a few countries are probably going to manufacturing the fuel needed for fusion reactors. Producing enough of it and in a sufficient purity needs specialized facilities and they will only be profitable if they produce a lot of it.
constantcrying 1y ago
These reactors are build for research, so presumably they need to be more modular, have more measuring components and be more accessible for changes.
vjvjvjvjghv 1y ago
That's how it goes most of the time. First you have to make it work somehow, often in a very complex way. Once you have something that works, either you can strip away a lot or the components get commoditized and you can buy them in a nice package. A lot of our devices are super complex but you can build a device without much knowledge because the complexity is hidden away in nicely packaged components.

alpineman 1y ago

Old article, from June...don't get me excited

brohee 1y ago

Does it kill the idea of a tokamak as an energy production device? As in a stellarator proving the much more promising design...

Lev1a 1y ago
Not an expert on the topic by any means, but IIRC: - Those designs have been in parallel R&D for decades - Tokamaks are conceptually simpler, thus might be easier/faster/cheaper to make into viable installations - Stellarators are WAAAAAY more complex to design and build but AFAIU they would have the huge benefit of being able to sustain the plasma for way longer for the same "startup cost" of a cycle since the particles of the plasma are routed somewhat like they're on a mobius strip instead of a simple torus (which should make it easier to confine more particles for a longer time). I recall having read (several years ago) that the simulation technology of the 90's wasn't really up to the task of aiding in the design of those weird wavy magnets for Wendelstein 7-X, an unfortunate reality which delayed the project a lot.
Miraste 1y ago
I'm no expert, but from the full press release it appears this experiment is the first time they've even been competitive with tokamaks, and are still behind the latest (unpublished) tokamak results.
cyberax 1y ago
It'll be a question of manufacturing. A tokamak is a fairly simple torus, with at least some similar parts. Stellerators are freakishly complicated 3D structures that require submillimeter precision. So it might end up being cheaper to construct a larger tokamak.
HarHarVeryFunny 1y ago
Perhaps, unless you fall prey to the sunk cost fallacy and have already spent a bazillion dollars on generations of tokamaks!
runxel 1y ago
Both ideas are pretty old (50s) and in development for a long time. Both designs have their pros and cons. The biggest drawback of the Tokamak however is that it can only be pulsed... which is kind of dumb to actually generate and provide energy in the long run. You really want the Stellarator here, since there it is at least theoretically possible to run "for ever" (not entirely true, but long enough cycles to be used in a power plant). There are 2 podcast episodes with the guys who run Wendelstein here: http://www.alternativlos.org/51/ http://www.alternativlos.org/51/ (it's German tho)

wedn3sday 1y ago

I've always been somewhat partial to the stellarator design, I mean a big plasma donut is cool and all, but what if we twisted it around a whole bunch first!?

cgannett 1y ago
mmmm plasma cruller uhuhuhuhuhu -Homer Simpson
HarHarVeryFunny 1y ago
I think gravitational confinement is the way to go - it's the only operationally proven design! Gotta think big!
- weregiraffe 1y ago
  No, it's not the only proven design. The other is a hydrogen bomb. Google project PACER.
  - HarHarVeryFunny 1y ago
    True - inertial confinement - also used by NIF (laser based). I guess I should have said continuous operation, although I do like the simplicity of Helion's system.
- exe34 1y ago
  You only need one at that point!
- ars 1y ago
  It has density issues though. If you had a piece of the sun the size of a huge power plant - like enormous, the power output would be too low to be useful.
  - grumbelbart 1y ago
    Mandatory: We should build it in space and beam the electricity back to earth using electromagnetic waves. We could collect those using solar cells. And then get rid of the plant and use the sun instead.

bradleyy 1y ago

In any future fusion power plant, a plasma with a high triple product must be maintained for long periods. I love vague terms like "long periods". Long compared to the Planck length? Geological time? Is the advertised 43 seconds almost there or "off by 17 orders of magnitude?"

dmbche 1y ago
I believe it's "for as long as the reactor is to be operating", and they contrast that with the previous longest times being less than 45 seconds.
- Analemma_ 1y ago
  I thought the expectation was that actually-operating fusion plants would operate in pulses rather than continuously, but I could be misremembering.
  - smallerize 1y ago
    Toroidal reactors have to operate in pulses. Stellarators can be operated in steady-state (although sometimes they are pulsed to achieve higher energy).
    - rnhmjoj 1y ago
      Tokamaks can also be operated in steady-state, at least theoretically. The reason a tokamak is pulsed is due to the fact the toroidal current is driven inductively, so there is a limit to how long you can keep increasing the current in the central solenoid. However there are other methods, for example, neutral beam injection and electron cyclotron current drive. You can even exploit the bootstrap current (self-generated by collisional processes in the plasma) to obtain a near 100% non-inductive toroidal plasma (this is called "advanced tokamak" regime). Anyway, the older generation of devices was pulsed for engineering reasons (like non-superconducting coils getting too hot). The current generation of device is solving most of these and is limited by MHD instabilities alone (neoclassical tearing modes, mostly), if we can get active control mechanism working, then will be finally approach the long-pulse or steady-state regime.

tgtweak 1y ago

This article has zero quantifiable information in it aside from the duration... which has no context. Who's recordkeeping this stuff? What are the other results so far? What is the tipping point where it is net positive? how long does it need to sustain a net positive fusion reaction to produce sufficient power for grid consumption? Are there other losses (thermal generation inefficiencies) that make the target even farther than energy-in<energy-out?

colechristensen 1y ago
>What is the tipping point where it is net positive? There are several interesting net positive tipping points depending on where you draw the boundary that energy in and energy out cross. We're still in the earlier stages of net positive where the boundary is quite small and little consideration is being given to the part of the process where electrons get pushed around in a power grid.
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tgtweak 1y ago
Here is an actual article with some context - and a reality check that other experimental reactors in the past have sustained similar triple product for longer durations... https://www.ipp.mpg.de/5532945/w7x https://www.ipp.mpg.de/5532945/w7x
- i_am_proteus 1y ago
  >The fact that W7-X results are on a par with JET is remarkable because JET had three times the plasma volume of Wendelstein 7-X. What's important here is that W 7-X is a stellarator, a different type of fusion reactor from almost all prior reactors (they are tokamaks), with a smaller volume than the co-record holder. That a stellarator gets these results with a much smaller fusion volume is promising for the performance of future larger stellarators, since fusion reactors typically become more efficient as they get larger.
  - 1y ago

cubefox 1y ago

The article links to the original source, which has more details: https://www.ipp.mpg.de/5532945/w7x https://www.ipp.mpg.de/5532945/w7x

chris_va 1y ago

A better link: https://www.ipp.mpg.de/5532945/w7x?c=5481737 https://www.ipp.mpg.de/5532945/w7x?c=5481737 (there is some irony in using the iter.org link for a stellarator announcement) 1.8GJ over 360 seconds, beta of 0.03

perihelions 1y ago
> "1.8GJ over 360 seconds" Not sure if this is contextually obvious to practitioners, but that figure is the "Energy turnover" / "is calculated as the product of injected heating power and plasma duration".
greesil 1y ago
The irony is delicious. Especially considering the total budget of it is $340 millions vs ITER's tens of billions.
- WhereIsTheTruth 1y ago
  Their findings complement and help each other, there is no irony in there
  - greesil 1y ago
    Of course they can complement each other but ITER can still be an inefficient use of science funds at the same time.
- Ey7NFZ3P0nzAe 1y ago
  To be fair, they might not be totally independent figures in the sense of, I would be surprised if the cheaper project did not benefit at all from the knowledge created by the larger project.
  - ygra 1y ago
    Help on either project actually flows both ways. If I remember correctly, Wendelstein 7-X provided experience and know-how regarding microwave heating and welding large plasma vessels. In the end they're scientists and engineers and don't seem to see the other project so much as competition than a way to learn more than just with one of them.

sheepscreek 1y ago

TL;DR - Looks dangerous, but is it? (open question) Can we quantify it or at least make it more tangible? God, this contraption appears to be the kind of thing I wouldn’t trust my life with. Every time I look at a fusion reactor, it seems far more dangerous than my hobby lab, failing to inspire any confidence. The numerous moving parts create an equal number of potential points of failure. In contrast, a nuclear reactor doesn’t have to contend with plasma gases hotter than the Sun, contained within an artificial bubble solely through the assistance of electromagnetic radiation. I’ve often tried to imagine the worst case scenario, but I am limited by my knowledge on the subject. What kind of damage can hot plasma at a few million degree C do? On one hand, the plasma is hotter than anything on earth created by mankind. Then I believe there’s also a significant number of wild neutrons shooting around which can cause havoc in their own right, if not contained. But on the other hand, unlike an uncontrolled chain reaction, without a source of heat, the whole operation shuts off by itself. I’m probably wrong about a few assumptions here but this is what I often find myself wondering.

thinkcontext 1y ago
That fusion reactions are so difficult to get started makes the reactors very safe because failure makes them stop. So, if you lose magnetic confinement the reaction stops. The reactor may be damaged but that's it. This is unlike fission reactors, where a failure causes reactivity to increase. That causes meltdown and the possibility of explosion and all the nasty radioactive contamination.
- mathw 1y ago
  My understanding is that more recent fission reactor designs are done in such a way that they fail in ways which cause the reaction to diminish rather than build up further, which puts you in a better place than, say, Chernobyl. You still have a very hot very radioactive lump of death in the middle of your busted reactor when it's all done though, and that's definitely not fun. Fusion failure modes - in current designs anyway - are far more appealing to anybody who happens to be in the area at the time.
Workaccount2 1y ago