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Germany Fires Up Bizarre New Fusion Reactor (sciencemag.org) 186

Posted by timothy from the that-dog's-not-that-radioactive dept.
New submitter insitus writes: On 10 December, Germany's new Wendelstein 7-X stellarator was fired up for the first time, rounding off a construction effort that took nearly 2 decades and cost €1 billion. Initially and for the first couple of months, the reactor will be filled with helium—an unreactive gas—so that operators can make sure that they can control and heat the gas effectively. At the end of January, experiments will begin with hydrogen in an effort to show that fusing hydrogen isotopes can be a viable source of clean and virtually limitless energy.
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Germany Fires Up Bizarre New Fusion Reactor More

Germany Fires Up Bizarre New Fusion Reactor

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  • -- Stellarator-- (Score:5, Funny)

    by turkeydance ( 1266624 ) on Thursday December 10, 2015 @05:53PM (#51097511)
    great Jazz Fusion band name.

  • Wendelstein 7-X stellarator? (Score:5, Funny)

    by nwaack ( 3482871 ) on Thursday December 10, 2015 @06:02PM (#51097567)
    Is this a story from Futurama?

  • In all of the test fusion reactors I have seen there appears to be no mechanism to draw off the "excess" energy for use in power production. They all seem to be sealed units. So what are the conceptual ideas for taking the energy out from a fusion reactor?

    • Re:can someone please explain for me (Score:5, Informative)

      by viperidaenz ( 2515578 ) on Thursday December 10, 2015 @06:14PM (#51097629)

      Same as a fission reactor?
      The cooling system powers steam turbines

      • Re: (Score:2)

        by OzPeter ( 195038 )

        Same as a fission reactor?
        The cooling system powers steam turbines

        Yes .. but how? The devil is in the details. Are you jacketting the toroid in a cooling layer? or are collecting the energy via another method? (A poster below mentions the drawing off of helium that will be required for continuous operation - no idea if that harvests enough energy to be viable or not)

        • First of all, this reactor, like all current fusion reactors does not create excess energy.

          There are two ways to energy transferred out, one is to utilize the so called MHD effect (was in favour the last century), now people say that you need to breed tritium from lithium, so the have a shell of lithium around the reactor core. That core is heating up by hits of neutrons. From that core you can extract heat ... as some other poster said: like in an fission reactor to drive turbines.

          However: I doubt anyone ever did the math, you have "inside" a hot core that needs to get heat to the "outside" to drive a steam engine. "In-between" you have super conducting cooled coils (close to absolute zero) which generate the magnetic containment field.

          But I guess, you can insulate the cooled coils good enough to bypass the heat transfer in a way that it is not disturbing the cooling of the coils.

        • Re: (Score:2, Interesting)

          by Anonymous Coward

          For Tokamaks, the energy-generation method involves catching high-energy particles emitted from the fusion reaction using a system on the outer shell of the containment vessel. This implies that the shell will degrade over time and need replacement, and that the containment vessel must be transparent to those particles. I'm going to assume that for an actual power-generating Stellarator design, there'd be a similar set-up -- unless there's some method by which the oddly-shaped magnetic field causes controll

      • Re:can someone please explain for me (Score:5, Interesting)

        by OzPeter ( 195038 ) on Thursday December 10, 2015 @06:56PM (#51097825)

        Take a look at the specs in TFA. The magnets in this system are cooled with liquid helium to -270 deg C. The plasma sits inside the magnets. Thus any energy extracted from the plasma has to cross the boundary of the magnets, while at the same time not upsetting the magnets themselves.. What I want is an explanation of how this aspect is being considered. Once you have the energy out of the core you can pipe it into turbines to produce electricity. But that part is easily done.

        • Re: (Score:3)

          by suutar ( 1860506 )

          Sounds ripe for a typical heat pump system using the liquid helium as the refrigerant.

          • Pesky thermodynamics of heat engines is going to be a problem here. Heat pumps require work input to move heat from a low temperature to a high one but you can get work out of heat flowing from a high temperature to a low one with a heat engine.

            So.... The problem is (starting from INSIDE the reactor) you go from REALLY HIGH -> RELLY LOW -> ROOM temperature and unless you can harness the first transition and get work out of it, all you are going to do is put work into this....

          • Sounds ripe for a typical heat pump system using the liquid helium as the refrigerant.

            Yup. All you need is a 2K heat sink, and you are good to go.

        • I think that the best option would probably be a helium heat jacket between the plasma and the rest of the structure. The helium becomes super-heated by transitioning the structure, then is piped to the turbines.

          By utilizing helium you can utilize a much wider temperature range(for efficiency) without crazy-high pressures.

        • > What I want is an explanation of how this aspect is being considered.

          Go here:

          https://matter2energy.wordpress.com/2012/10/26/why-fusion-will-never-happen/

          Look for the image of DEMO. The large red part is the answer to your question. The magnets are in green. Red protects the green and removes the energy.

          And then you can read the text, and find out why it's all a crock of crap anyway.

    • Re: (Score:3, Informative)

      by 31415926535897 ( 702314 )

      Heat. Thermal transfer to steam turbines. It would be sweet if we could directly extract the energy, but there's no known way of doing that yet. The turbine method is decently efficient, though.

      • Re: (Score:3)

        by OzPeter ( 195038 )

        Heat. Thermal transfer to steam turbines.

        Standard PWR fission reactors use a 2 stage liquid/steam system to move energy from the core to the turbines. The first stage is flowing the liquid directly over the core inside the reactor vessel, which in turn keeps the reactor vessel at a decent temperature. But you can't do this with a fusion set up due to not being able to get to the inside of the (in this case) toroid. Thus all of the produced energy seems like it has to flow through the toroid walls in order to escape the reactor vessel - which wo

      • Wrong.
        All Impulse based (yes, that means stellarators) fusion reactors produce huge magnetic flux changes during the superheat fusion cycle.
        AC coupling this is power to the intermediate storage, which so far does not exist.
        Nothing new, and nothing will work.

        • Re: (Score:2)

          by Sique ( 173459 )
          Tokamak type reactors are impulse based, the Stellarator is not. In TFA, they point out exactly that:

          But tokamaks have serious drawbacks. A transformer can drive a current in the plasma only in short pulses that would not suit a commercial fusion reactor. Current in the plasma can also falter unexpectedly, resulting in “disruptions”: sudden losses of plasma confinement that can unleash magnetic forces powerful enough to damage the reactor. Such problems plague even up-and-coming designs such as the spherical tokamak (Science, 22 May, p. 854).

          Stellarators, however, are immune. Their fields come entirely from external coils, which don’t need to be pulsed, and there is no plasma current to suffer disruptions.

      • > It would be sweet if we could directly extract the energy

        Supposedly these guys are trying for a more direct way to generate electricity from the plasma: https://www.youtube.com/watch?... [youtube.com]

        • > Supposedly these guys are trying for a more direct way to generate electricity from the plasma

          Only in the case where the plasma is being made with fuels that are aneutronic. In that case you might increase the energy efficiency from about 40% to as much as 60%. However, such fuels are about 1000 times more difficult to use for power generation, so the concept is utterly hopeless, which they simply ignore and rely on magical statements about their designs, none of which have ever been demonstrated.

          Inter

    • Re:can someone please explain for me (Score:5, Interesting)

      by Rei ( 128717 ) on Thursday December 10, 2015 @06:25PM (#51097681) Homepage

      You don't have to "draw off" energy - the plasma is more than happy to lose heat to its surroundings. The biggest challenge with fusion is to stop the plasma from giving up its energy too fast!

      That said, for continuously operating toruses you do have to "draw off" the "ash" (helium) by means of an "exhaust" system that juts up into the outer reaches of the plasma stream (where the heavier helium concentrates), which is "a" challenge (the component is subject to a very hostile environment and faces huge thermal loads), but it's not a showstopper challenge by any means.

      • Re: (Score:2)

        by OzPeter ( 195038 )

        That said, for continuously operating toruses you do have to "draw off" the "ash" (helium) by means of an "exhaust" system that juts up into the outer reaches of the plasma stream (where the heavier helium concentrates), which is "a" challenge (the component is subject to a very hostile environment and faces huge thermal loads), but it's not a showstopper challenge by any means.

        So what sort of mass of helium are we talking about? (I have no understanding of the scales involved) and is this a viable way of bleeding off energy? (and if so will that make fusion reactors potentially the worlds best source for helium?)

      • I thought the biggest challenge was the neutron activation of the inside of the reactor?

    • Re: (Score:2)

      by dlenmn ( 145080 )

      As several posters have mentioned, the simplest way is to just use the heat to boil water. There reason you don't see giant water lines in existing reactors is that there's no point; they're experiments -- not powerplants.

      Some years ago, I asked a plasma physics prof if there were other methods to get energy out of a reactor, and he said that there were -- at least in principle. Unfortunately, I don't recall the answer. There's a very large number of charged particles whizzing around in a reactor, so I can

      • Here (Score:5, Interesting)

        by dlenmn ( 145080 ) on Thursday December 10, 2015 @06:48PM (#51097781)

        I should have wikied before I posted:

        https://en.wikipedia.org/wiki/... [wikipedia.org]

      • Re: (Score:2)

        by OzPeter ( 195038 )

        As several posters have mentioned, the simplest way is to just use the heat to boil water.

        The boiling water part is still non trivial for a fusion reactor because of those pesky magnets you need to keep at rather low temps in order to contain the plasma. I think you may be better off with direct conversion that you mentioned below. And that was the sort of link I was looking for.

      • As several posters have mentioned, the simplest way is to just use the heat to boil water.
        As several people have mentioned, there is no simple way to use the heat to boil water

        and he said that there were -- at least in principle MHD effect.
        https://en.wikipedia.org/wiki/... [wikipedia.org]
        https://en.wikipedia.org/wiki/... [wikipedia.org]

        • That's great except that about eighty percent of the energy from the deuterium-tritium reaction is kinetic energy of the resulting neutron, and MHD won't let you gather energy from a neutron. Capturing the neutron's energy is further complicated by the fact that the neutron is produced isotropically, and that you need to breed more tritium with that neutron before or after you heat water or some other working fluid.

    • Re:can someone please explain for me (Score:5, Informative)

      by Anonymous Coward on Thursday December 10, 2015 @09:03PM (#51098283)

      So what are the conceptual ideas for taking the energy out from a fusion reactor?

      They have a FAQ [ipp.mpg.de] which includes an answer to your question [ipp.mpg.de].

  • Germany Fires Up Bizarre New Fusion Reactor

    Could at least give a hint as to what's so bizarre about it in the summary.

    Y'know, as opposed to all those boring run-of-the-mill fusion reactors...

  • Dup......ish (Score:5, Informative)

    by Nova Express ( 100383 ) <lawrenceperson@g ... inus threevowels> on Thursday December 10, 2015 @06:10PM (#51097613) Homepage Journal

    FTA: "This story was originally published online on 21 October and in the 23 October issue of Science. It has been updated with new information."

    And yes, this story was on Slashdot then [slashdot.org].

  • Good name (Score:5, Funny)

    by slashmydots ( 2189826 ) on Thursday December 10, 2015 @06:22PM (#51097671)
    Everyone's going to say that it's finally the Mr Fusion from Back to the Future. Noooo. It's Das Mister Fusion. It's German.

  • interesting note about the design (Score:3)

    by Gravis Zero ( 934156 ) on Thursday December 10, 2015 @06:53PM (#51097803)

    if you haven't heard much about the "stellarator", the twisted design is actually a resulting design from an evolutionary algorithm. [researchgate.net]

    robotic evolution will happen quickly. [youtube.com]

  • hydrogen... (Score:5, Funny)

    by tapia ( 125876 ) on Thursday December 10, 2015 @07:15PM (#51097909)

    Nothing says success like the juxtaposition of "Germany" and "technological innovation involving a hydrogen filled container".

    • Re:hydrogen... (Score:5, Interesting)

      by bobbied ( 2522392 ) on Thursday December 10, 2015 @08:23PM (#51098143)

      Hey, to be fair.... Their Zeppelins where the killer technology of the day and even though they sparked a bit less than a revolution in transportation technology they certainly where on the cutting edge. Had the Hindenburg not burned and crashed in Lakehurst JN, live on the radio, I dare say these things would have at least changed the investment mix in passenger aviation up until war broke out two years later...

      What you really need to look out for is how useless various Germen inventions turn out to actually be to the Germans themselves. They have had horrible luck in their timing... The zeppelin rage which would have ended abruptly at the start of WW2, even without the burn and crash that ended it 2 years sooner. The development of modern rocketry, only to have it's effectiveness fail to alter the effort to prevail in war, the fielding of the ONLY jet fighter of WW2 which out classed and out ran ANYTHING flying only too late to make a difference. Their inventions of navigating aircraft to precise locations over long distances using this new radio technology and the invention of RADAR prior to WW2. No Germany has lots of luck inventing things, but horrible luck with the timing and application of them.

      • Re:hydrogen... (Score:4, Informative)

        by binarstu ( 720435 ) on Thursday December 10, 2015 @10:48PM (#51098619)

        ...the fielding of the ONLY jet fighter of WW2 [by Germany] which out classed and out ran ANYTHING flying only too late to make a difference.

        Not true. The British Royal Air Force developed and flew the Gloster Meteor [wikipedia.org] in World War II, which was another jet fighter of the time.

        • The US was also in the jet race. The P-59(?) wasn't any better than contemporary piston-engined fighters, and never reached service. Two P-80s were used in Italy in a recon run, more for show than anything else. Unlike Britain and Germany, the US did not have jet fighters in service during the war.

    • Re:hydrogen... (Score:5, Interesting)

      by Anonymous Coward on Thursday December 10, 2015 @09:48PM (#51098455)

      Nothing says success like the juxtaposition of "Germany" and "technological innovation involving a hydrogen filled container".

      Hydrogen didn't bring down Hindenburg. It was pilot error. Here is what most likely happened:

      Hindenburg was 12 hours late and would be even more late due to a thunderstorm. To prevent being so late that they had to delay the return trip too, the captain decided to go closer to the thunderstorm than normally allowed. On arrival, he decided to land even though the winds exceeded the limits for allowing landing. So far everything has been facts. The next is speculation based on circumstantial evidence and later tests.

      A gust of wind threw Hindenburg out of the landing approach and to counter that, full rudder was applied. This was not allowed during landing due to structural stress and a wire holding the shape of the "cigar" snapped and punctured a hydrogen container. The ship was statically charged from flying too close to the thunderstorm. As a guidewire touched the ground and the front of the ship at the same time, the front suddenly started burning, presumably started by a static discharge. Based on color descriptions of the fire, the fire started in the water protecting coat on the canvas. After that burned for a while, it reached the leaked hydrogen.

      Here is the thing: if the ship used helium and not hydrogen, it would still have burned and crashed. It was doomed even before the hydrogen caught fire. Even prior to the accident, the coating was disputed due to safety concerns. It was really good at keeping the water out, but the fire hazard was ignored and some of the few knowing this objected in writing. This writing still exist. Also had the captain decided to delay further due to safety concerns, nothing bad would have happened to him and the accident would have been avoided. However his pride didn't allow that and on behalf of Germany he wanted to return to Europe in time for the passengers to make it to the Coronation of King George VI and Queen Elizabeth. Sure that was important, but important enough to crash?

      This type of accident is not unique to Germany or the past. In 2001, American Airlines Flight 587 taking off from New York encountered wake turbulence from the plane ahead of it. The pilot used the rudder quite a lot to counter it, despite the fact that full rudder is banned at that altitude/speed due to structural concerns of the plane. Parts of the tail fell off, the plane went out of control and crashed into Queens. It turned out that the pilot did precisely what he was told to do during training and a faulty training program was the main cause of the accident. Needless to say wake turbulence countermeasure training changed overnight.

    • If only they had started the war a few years later, imagine how it would have turned out for them... Or better stil, you know, not at all.

  • Am I understanding correctly in likening the twisted plasma flow in this reactor design to how a twisted-pair cable works?
    • No. Not at all.
    • Um.... Not exactly as there is no pair here and in "Twisted pair" the second conductor is key to how noise coupling is reduced by twisting two conductors.. However, if it helps you visualize it, feel free to think about it that way. What this design does is make the magnetic fields required smoother and easier to manage by giving the whole thing a bit of build in springiness as best I can tell. But hey, I'm just a software engineering geek who is trying to figure out how they think they can get the heat
      • I should have been more descriptive. What I meant was how a twisted-pair cable cancels out common-mode noise, and how a differential pair also doesn't radiate much, because the magnetic fields are 180 degrees out of phase, so they cancel. Is that a fair approximation of what's going on here, the magnetic field that the plasma is generating is cancelling itself out because it's twisted?

    • Re: (Score:2)

      by aXis100 ( 690904 )

      It's similar but almost completely unlike the twisting in twisted pair.

      A normal toroidal tokomak has the magnets closer together and the centre than at the outside, and the variation in the resulting magnetic field leads to instabilities. The twist in the stellerator is supposed to ensure that the variations in magnetic field all get cancelled out as the plasma circulates.

    • > Am I understanding correctly in likening the twisted plasma flow in this reactor design to how a twisted-pair cable works?

      No.

      Consider the fuel in a steady state. What we call heat is microscopically speed, and in this case all the ions are circulating around the torus very rapidly. Now think about the way the magnets are placed around the torus, as a series of rings. Because the rings are closer together on the inside radius, that means there is a stronger field on the inside of the torus than the outs

  • Two things I don't quite get (Score:3)

    by Joe Gillian ( 3683399 ) on Thursday December 10, 2015 @08:30PM (#51098177)

    What I don't understand is how they plan to heat a gas to 100 million degrees centigrade.. or what materials they're using to contain it. Most metals have a melting point of between 2500 and 3500 degrees centigrade. Even assuming the superheated gas doesn't directly touch the structural components, convection would surely still heat any containing material to its melting point. What are they using to contain it?

    • Re:Two things I don't quite get (Score:4, Insightful)

      by bigfinger76 ( 2923613 ) on Thursday December 10, 2015 @08:36PM (#51098209)
      A magnetic field.

    • The gas does not touch the walls ... it is in a magnetic "bottle".

      Secondly and utter more important: the amount of gas is roughly equivalent to a pint of beer. It is thinned out in a vacuum a few 100 times that volume. That means the temperature as a "number" is close to meaningless (unless you are a plasma physicist). Exagerated: the whole energy in the plasma is less than you need to heat 20 pints of water.

    • Re: (Score:2)

      by ledow ( 319597 )

      They don't need to heat up a gas. They need to heat up one atom at a time. Or a handful at most.

      As such, the amount of energy to get it to millions of degrees is almost nothing. The only reason your bath takes so long to heat up is because of the AMOUNT of water you need heated. Even a few extra litres can take measurably longer to heat (e.g. shower vs bath efficiency).

      But with fusion, when you pop that atom, you get more energy out than you put in. The actual problem is not in "how do you get that hot

    • As for heating, they need only to heat a very tiny portion of it to ignite the fusion; it will sustain itself later on - so lasers or masers...
      The power losses come from the containment requirements - the reactor doesn't break even with that but the fusion does produce power to heat itself - just not enough surplus to power the magnets.

  • So that really hot Vril chick with the long hair has come back.
  • I really hope it works well and produces abundant energy. But just why is the US not ahead on this type of reactor? Is it political or do we lack the ability?

    • Reading the article, it seems the US was on its way to building one like this, but ran out of money. Kinda par for the course with public-funded projects in the US these days.

      • What they should do is figure out how to sell it as a light rail project in Minnesota. We spend billions of dollars building and running those things yet they only really see use when there is a sporting event downtown. Additionally they might try selling it as a sporting arena here as we seem to be building a bunch of those things as well.

  • Event Horizon (Score:3)

    by DarthVain ( 724186 ) on Friday December 11, 2015 @09:57AM (#51100127)

    ...and opened up a gateway to hell!

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