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Power Science

New 'Stellarator' Design for Fusion Reactors 171

eldavojohn writes "The holy grail of fusion reactors has always seemed 'just a few years off' for many decades. But a recent design enhancement termed a 'Stellarator' may change all that. The point at which a fusion reactor crashes is when particles begin escaping due to disruptions in the plasma. A NYU team has discovered that coiling specific wires to form a magnetic field may contain the plasma. This may be a a viable way to create a plasma body with axial symmetry, and a far better chance of remaining stable. Like other forms of containment this does require energy itself, but could bring us closer to a stable fusion reactor. It may not be cold fusion or 'table top' fusion but it certainly is a step forward. The paper is up for peer review in the Proceedings of the National Academy of Sciences."
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New 'Stellarator' Design for Fusion Reactors

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  • by Anonymous Coward on Friday August 10, 2007 @06:42PM (#20190041)
    ...they want credit.
  • Re:input-output (Score:4, Insightful)

    by Paul Pierce ( 739303 ) on Friday August 10, 2007 @07:01PM (#20190251) Homepage

    Like other forms of containment this does require energy itself
    I find it weird that the amount of energy needed to contain, is less than the energy contained in the plasma. Can anyone explain this ?

    Picture Chinese handcuffs
  • Re:If they used... (Score:1, Insightful)

    by Anonymous Coward on Friday August 10, 2007 @07:10PM (#20190369)
    The whole thing is a huge CON and a case of lifetime 'jobs for the boys' - a bunch of overblown assholes who aren't remotely interested in finding a CHEAP energy source - they want a CENTRALISED energy source that a government can completely control.

    We already can get ALL the energy we need from renewable sources - ITER and its ilk are just money pits, and guess who pays for this bullshit? The PUBLIC.

    It's always "It'll be ready in 50 years' time". i.e. in 50 years' time, they'll STILL be saying "It'll be ready in 50 years' time".

  • by Zarhan ( 415465 ) on Friday August 10, 2007 @07:13PM (#20190391)
    ...and as prototypes too.

    http://en.wikipedia.org/wiki/Stellarator [wikipedia.org]

    Anyway, basically what I know about this is that stellarator designs avoids lots of the problems that are present in Tokamak - namely, degrading of the reaction chamber due to escaped neutrons. A fusion reactor using stellarator instead of Tokamak would, in effect, last forever since the material does not become radioactive.

    Especially the Germans have been researching this stuff a lot, however, most of the big money is currently in Tokamak designs, including ITER. Which is kinda a shame - since we're not in the Manhattan Project-type "if you have 3 designs and think one of them might work, build all three, here's the money"-situation..so these nice ideas may only be developed further if Tokamak fails to become viable..
  • by lawpoop ( 604919 ) on Friday August 10, 2007 @08:14PM (#20190981) Homepage Journal

    This seems like the exact reason why basic physics should be mandatory in schools.
    Okay...

    Dear God. How exactly would a magnetic field contain neutral photons ? They will generate zero flux and will not interact with the field at all.
    Is this the kind of basic physics that the average student would understand in their mandatory class?
  • Re:input-output (Score:1, Insightful)

    by Anonymous Coward on Friday August 10, 2007 @10:03PM (#20191651)
    just like it's easier to destroy than create...

    Actually, at a fundamental physical level, that's untrue. The only thing that costs energy is erasure of information.

  • by Lord Balto ( 973273 ) on Friday August 10, 2007 @11:04PM (#20192083)
    For the $1,000,000,000,000 Monkey Boy will spend in Iraq we could have put solar collectors on every home in America for free. So they finally figure out how to make fusion work. Energy will still be monopolized by the power companies and you'll still be paying through the nose. And if you try to do anything about it they'll call you an enemy combatant and send you to Guantanamo. There is no technological fix. There is only a political fix.
  • Re:If they used... (Score:5, Insightful)

    by The_Wilschon ( 782534 ) on Saturday August 11, 2007 @02:08AM (#20193075) Homepage
    Blast radius my foot. A fusion reactor is immensely safer than a fission reactor. Furthermore, fission reactors are really very safe (far safer than, say, oil refineries). Even Chernobyl was primarily a /chemical/ explosion (although caused by problems with the reactor), which happened to scatter radioactive debris over half the globe. A chemical explosion at a fusion plant would scatter hydrogen. Oh boy. Even the unstable isotopes of hydrogen are still light enough that they would float to the top of the atmosphere and escape into space in very little time. A fusion reactor is not a controlled H-bomb. Unlike a fission reactor, which requires a carefully tuned reaction to walk the knife's edge between dying out and going critical, the hard part with fusion is keeping it going. Fusion is very fussy. If the density, and the temperature, and the composition of the plasma are not just exactly right, then reaction dies out in a fraction of a second, the time it takes to exhaust the really tiny amount of fuel that is available to it at any given time. To keep it going, you have to keep feeding it more fuel, as well as carefully tuning things. If there were even a very very tiny explosion, the worst it would do is damage the devices tuning the plasma's parameters, and then the reaction would die out. Even if the fuel feeders went crazy and started flooding hydrogen in as fast as they could, it would still just die out. There is no way that the reactor, even in an undamaged state, could bring enough hydrogen to the needed density and temperature quickly enough to cause a thermonuclear explosion even on the scale of a pipe bomb. So, I say, blast radius my foot, unless you want to compress the researchers down very very small and put them inside the plasma itself.

    Researchers are not involved in corner cases that might never happen. Nor are they worried about reliability yet (in the sense of preventing another Chernobyl, as opposed to the sense of very little downtime). They are just trying to get the blamed thing to produce enough energy to sustain itself, with some left over. (Although, if you're feeling pessimistic enough, you might call that a corner case that might never happen!)

    I agree that we need to get a lot of funding to fusion research, but throwing money at the problem won't necessarily solve it. It is a very hard problem. Furthermore, we'd need not just one crazy (I presume you refer to the office of the President), but a whole bunch of crazies (half of Congress), because Congress makes the budget.
  • Re:If they used... (Score:3, Insightful)

    by joto ( 134244 ) on Saturday August 11, 2007 @03:02AM (#20193301)

    We already can get ALL the energy we need from renewable sources

    That might be so, but it certainly isn't economical, otherwise we would already have all our energy from renewable sources. Furthermore, very few renewable sources of energy shows any sign of promise in the short term, although solar certainly seems interesting once someone comes up with a "breakthrough". Oh, and we could build more dams, they can certainly be profitable, but often takes a huge toll on mother nature.

    a bunch of overblown assholes who aren't remotely interested in finding a CHEAP energy source - they want a CENTRALISED energy source that a government can completely control.

    Actually, centralized makes a lot of economic sense. There is only one way of generating power that is at least potentially profitable at a small scale, and that is solar cells. But even here, you get economic benefits by simply aggregating them in a small area, which simplifies maintenance and infrastructure. Nuclear just doesn't scale down at all, and everything else, is simply more efficient at a larger scale, whether it's wind-turbines, dams, wave-turbines, geothermal, waste energy from industry, burning of garbage or methane from a landfill, or even gas, diesel, or coal. If you don't believe me, try putting up a small propeller in your backyard, and compare the $/watt of this to a typical 100 meter wind turbine, or to a huge turbine farm with 100 meter turbines. Or compare the $/watt of a small waterwheel to the Hoover Dam. Or compare the efficiency of a diesel-generator you can afford, to one that you can only afford to rent, or to one that is able to power a whole city. These things might scale down, but certainly not in an economical way.

    It's always "It'll be ready in 50 years' time". i.e. in 50 years' time, they'll STILL be saying "It'll be ready in 50 years' time".

    This is certainly a valid criticism for fusion power research. But I hope you don't seriously believe that just because you can't have it today, we should stop researching it. The benefits of such a technology would be incredible, and the money we spend on it is not that much. Still, one can debate whether pouring money into tokamak research is justified given its track record so far, This, however, is not a tokamak, and as such is a potential theoretical breakthrough, even if it might be an unlikely one (I'm not qualified to judge that).

  • by Anonymous Coward on Saturday August 11, 2007 @04:08PM (#20197563)
    To start off, I am a plasma physicist. I have never seen any estimates coming from the plasma physics world claiming that a commercial stellarator reactor is less than 50 years off. I don't know where this "a couple of years away" keeps coming from. That isn't to say that early estimates of the difficulty of building a fusion reactor weren't wildly off. I just think that current estimates, while somewhat optimistic, are informed by a lot more science than those early estimates. We've learned a lot in the past 50 years.

    Even commercial tokamaks, which have quite a head start over the stellarator, are projected to be pretty far off. If ITER's construction and initial operation is wildly successful, it won't be fully operational for 20 years, and it is expected that there will be one or two more iterations (depending on who you ask) before the first commercial tokomak is designed.

    Another confounding factor in correctly estimating a date for commercial fusion power is that the funding for such projects has been somewhat irregular, and any estimate of how long it will take to develop such a reactor is, in effect, also an estimate of how much various governments will be willing to spend on that research.

    The long and the short of it is that I think this characterization of fusion researchers as grossly over-promising is unfair, and untrue. Making estimates of any technologically difficult project is hard.

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