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Power Science

More Evidence for Tabletop Fusion 244

Posted by Zonk from the my-favorite-atomic-reaction dept.
heptapod writes "Researchers at Purdue University have statistically significant evidence that their tabletop fusion experiments were successful. Yiban Xu's experiment different from an earlier Oak Ridge experiment using a different and cheaper source of neutrons than Oak Ridge's pulse neutron generator. Surpassing break-even point still eludes the grasp of science."
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More Evidence for Tabletop Fusion More

More Evidence for Tabletop Fusion

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  • Break Even is Easy... (Score:2, Informative)

    by Anonymous Coward
    Surpassing break even is easy, we did it decades ago... What we are missing is a really big boiler, to make it work.

  • Someone say breakeven? (Score:3, Interesting)

    by deglr6328 ( 150198 ) on Saturday July 16, 2005 @11:35PM (#13085047)
    "Surpassing break-even point still eludes the grasp of science."

    hmmm does it [atominfo.org]?

    • I've never seen the calculations for that, but I would guess there's a good chance that even fusion reactions in bombs didn't surpass the break-even point. You have to consider the amount of energy expended in the harvesting and processing of the raw materials and construction of the device itself.

      • Re:Someone say breakeven? (Score:5, Insightful)

        by deglr6328 ( 150198 ) on Saturday July 16, 2005 @11:53PM (#13085108)
        Breakeven is defined as the point at which the fusion gain factor equals 1. In other words where the ratio of the power output of the fusing plasma is equal to the energy needed to maintain the plasma in a fusing condition. Thermonuclear devices by definition reach breakeven and ignition with high gain.

        If you are referring to the energy required to produce the plutonium and to separate the deuterium from water then they still VASTLY exceed in energy output the energy required to produce these things, as a typical fusion bomb is capable of releasing energies in the PETAjoule range (>10^15J).
        • In fact, even the most modern thermonuclear devices have an efficiency ratio of "only" 20% or so. The "Fat Man" bomb dropped on Hiroshima (?) in WWII had a ratio of only 1.4%. It only looks amazing because it's all released at the same instant.
          • forgive me for being skeptical of that 20% claim but....source? You only need literally a few Kg of Pu for the fission stage of an H-bomb (energy for production of the conventional explosive lenses for implosion is negligable (certainly in the Mj range)) and the energy required to produce the LiD fusion fuel is also quite small I'd imagine as you only need 110 Kg quantities. Litium mining energy costs are trivial and the energy it takes to separate D from seawater isn't extravagant. It occurs naturally at

          • Re:Someone say breakeven? (Score:4, Informative)

            by georgewilliamherbert ( 211790 ) on Sunday July 17, 2005 @12:36AM (#13085238)
            In fact, even the most modern thermonuclear devices have an efficiency ratio of "only" 20% or so.
            That's not true. Or rather, is such an oversimplification as to be grossly inaccurate.

            It's possible to build boosted fission primaries with fission efficiency up to about 50%. Such have been built and weaponized. Modern US devices have less efficiency (around 15%, in rough terms) because they are designed to use as little fissile material as possible and to be one-point safe, and also to have limited overall fission yield. Those requirements lead to less efficient weapons than are possible and were used in the past.

            Second, fusion, stages can be both highly efficient (50% or more of the possible fusion energy content) and have very high multiplication ratios of input to output energy (factor of 25 is possible, with factors of 8-15 in deployed US weapons), even before you double it again with a fissionable tamper third stage.

            Look at references like the Nuclear Weapons FAQ at http://nuclearweaponarchive.org/ [nuclearweaponarchive.org]

          • Re:Someone say breakeven? (Score:3, Insightful)

            by AJWM ( 19027 )
            I think you're using a different definition of efficiency, where "100%" is defined as converting all the mass of the weapon to energy.

            In which case your figures are way high. Fission bombs only convert about 0.001% of their mass to energy, early fusion bombs about 0.007%. The latter figure may be higher for modern weapons, but no where near 20%, or even 2%. I might believe 0.02%.
            • The 1.4% refers to the fraction of the Uranium in Little Boy that underwent fission before the weapon disassembled. Fat Man was something like 10% (can't find it in the Nuclear Weapons FAQ at 1 AM...). This was one of the reasons that Little Boy was the only gun-type bomb ever built.
      • Uh, the largest nuclear device was 50 megatons. Google says: 50 * 4.2 * ((10^22) ergs) = 5.83333333 × 10^10 kilowatt hours, which is alot of energy: 58,333,333,300 kw/hrs is one quarter of the world's yearly electrical demand.

  • ARTICLE MIRROR FOLLOWS (Score:5, Funny)

    by Anonymous Coward on Saturday July 16, 2005 @11:36PM (#13085051)
    WEST LAFAYETTE, Ind., July. 12 (AScribe Newswire) -- Researchers at Purdue University have new evidence supporting earlier findings by other scientists who designed an inexpensive "tabletop" device that uses sound waves to produce nuclear fusion reactions.

    The technology shows great promise, but critics have claimed that the tabletop device is just an iPod, and that the reactions it produces are not nuclear fusion, but Jazz fusion.

    "Bop Shop doo Wop", said Purdue Prof. Miles Davis in support of the technology.

  • Fusion (Score:4, Funny)

    by mboverload ( 657893 ) on Saturday July 16, 2005 @11:37PM (#13085054) Journal
    Will we get it before or after Duke Nukem Forever?

  • Re: More Evidence for Tabletop Fusion (Score:5, Informative)

    by lightyear4 ( 852813 ) on Saturday July 16, 2005 @11:38PM (#13085061)
    Statistical evidence of fusion at this level is indeed impressive; however, while fusion experiments such as this others [wikipedia.org] remain below the break-even point, they shall yet be little more than a labtable source of neutrons. We await developments from the latest [wikipedia.org] in the field.
    • I expect to to be 2050 when we get fusion.

      Well...at least that's when Sim City let me build one...

    • If further research into tabletop fusion results in decent efficiency, ITER may be obsolete before they finish building it.

      Granted we are not yet to the prototype powerplant scale of ITER with these proof of concept sized devices, but the difficulty in controlling plasma with magnets is far greater than bombarding something with neutrons and letting it do the work itself.

      • I wouldn't toss ITER aside before I get to at least read the journal article on a few of these desktop setups. I'd still like to see what pressure they're operating at, temperature ranges, D/T enrichment, reaction rate, bubble size, mcnp models (a vised geometric plot at the least), fluent models, etc. I just don't trust science magazine or a run of the mill newspaper to publish groundbreaking science that's on par for an engineer to read, since those cater to people without much knowledge of the engineer

    • I agree that mainstream fusion work will be important and is probably the right track toward a practical fusion powerplant.

      they shall yet be little more than a labtable source of neutrons

      However, remember that Cathode Ray tubes were also once little more than a labtable source of tightly controlled electrons. New sources of materials often lead into practical applications not originally envisioned.

  • break-even (Score:5, Insightful)

    by rbanffy ( 584143 ) on Saturday July 16, 2005 @11:42PM (#13085076) Homepage Journal
    Are they counting break-even as getting back more energy than needed to operate the ultrasound source ou they did count also the expense of producing the deuterated acetone and their expendable neutron source?

    It reminds me of when people say hydrogen burning cars will solve all emition problems because they produce water. They don't count the emissions that may be needed to produce, compress and ship the hydrogen to the nearest gas station.

    • Re:break-even (Score:2, Interesting)

      by Mikeydude750 ( 607965 )
      What about the energy costs of gasoline production? I love how people, in their attempt to discredit new technologies, talk about the "hidden" costs of these new technologies (I do realize they exist, however) while not remembering that our standard energy sources also have a signifigant number of "hidden" costs.

      But, even though you do have a small point, at least all the pollution is centered in one or two locations, instead of being spread all over thousands of miles by the vehicles themselves.

    • break-even isn't always the only concern... (Score:5, Insightful)

      by mcc ( 14761 ) <amcclure@purdue.edu> on Sunday July 17, 2005 @12:10AM (#13085156) Homepage
      It reminds me of when people say hydrogen burning cars will solve all emition problems because they produce water. They don't count the emissions that may be needed to produce, compress and ship the hydrogen to the nearest gas station.

      The trick with this one is in the may.

      Maybe someday we'll find a technology that's clean-burning and energy-efficient to the point where oil is no longer the most cost-effective way to make energy. Say, maybe nuclear fusion. Or maybe oil will eventually get so expensive that other energy technologies start to look not so bad by comparison. But if we ever reach this point, because of the massive installed base and economies of scale of oil systems, especially the ones in cars, we and our economies will still be dependent on oil. So it won't matter that the newer technology is better, we'll keep using oil anyway. That's bad.

      Hydrogen may at first be ultimately dependent on "dirty" oil and coal to make the hydrogen in the first place, but because it decouples energy production from energy use, in the long run it gives us the capacity to move on to better energy sources. It's like a nicotine patch, okay, it technically doesn't address the addiction but the thing is eventually you get to take the nicotine patch off.

      On top of this, there are situations where if you can't eliminate emissions, moving the emissions is a desirable second best thing. Like, of course we're not making advances in our contribution to global CO2 levels if all these cars in the city burning oil are replaced with a bunch of cars burning hydrogen [PLUS] one huge smoke-belching oil-burning hydrogen plant. But, well, if the city is Los Angeles, and the city is basically one huge smog-trapping bowl surrounded by mountains, and the smoke-belching hydrogen plant is on the other side of the mountains, then never mind the global CO2 levels, you've still made Los Angeles a significantly more pleasant place to live.
      • On top of this, there are situations where if you can't eliminate emissions, moving the emissions is a desirable second best thing.

        Don't forget that a million tiny engines that often burn fuel wastefully or ineffeciently pollute a heck of a lot more than one plant burning the same fuel but operating all the time at peak effeciency.

        To say nothing of the more environmentally friendly scurbbers that can be applied to a smokestack.

      • It reminds me of when people say hydrogen burning cars will solve all emition problems because they produce water. They don't count the emissions that may be needed to produce, compress and ship the hydrogen to the nearest gas station.

        The trick with this one is in the may.

        Maybe someday we'll find a technology that's clean-burning and energy-efficient to the point where oil is no longer the most cost-effective way to make energy.

        True, but IMO putting the focus on the hydrogen-aspect is wrong. The

      • So it won't matter that the newer technology is better, we'll keep using oil anyway.

        No we won't. The moment something better and cheaper* appears we'll jump in with both feet. GM will just stop trying, shed the last remnants of it vehicle manufacturing operation and evolve into a pure finance operation. You know who will buy the assets? Whoever can build "better and cheaper." Then we'll all have a new gang of mega-corps to complain about.

        Have some faith.

        * "Better and cheaper" does not yet exist. I
        • The moment something better and cheaper* appears we'll jump in with both feet.

          Perhaps, but I think it's equally likely that the corporations threatened by this new development will instead try to buy laws that prevent its actual use in order to maintain their outdated business model (along with their profits and their position at the top of the heap). Not that we can think of any current examples of this sort of thing happening, of course....

          Max

        • Re:break-even isn't always the only concern... (Score:5, Insightful)

          by The_Dougster ( 308194 ) on Sunday July 17, 2005 @03:45AM (#13085703) Homepage
          The moment something better and cheaper* appears we'll jump in with both feet.

          There is no doubt about that. Noble goals of reducing emissions and all that are great, but the sad fact is that companies are basically controlled by very greedy individuals. If they can be convinced that the company can "break into a new market segment" and have "tremendous growth potential" then they will throw money at whatever it is without much hesitation.

          Actually, the oil industry is writing its own epitaph by failing to keep prices down. At the current price levels, oil is only just slightly cheaper than some alternate fuels. I've heard an estimate that if gasoline were $4 per gallon then hydrogen becomes competitive. If oil prices go up much more then suddenly some other fuel will become more attractive and the fuel wars will begin in earnest.

          The thing is, oil is a finite resource and its price can ultimately only increase. Alternative fuels are typically synthesized and their price will eventually drop as better technology improves their production process. Because the alternatives are created from raw materials which are essentially unlimited, their price is primarily dependant on the process used to synthesize them.

          The question is: when will the two lines on the graph intersect. They are already drawing near enough that we are seeing things like biodiesel companies emerge. There will always be a niche market for fossil fuels, but decoupling cars and trucks from it would tremendously reduce consumption.

          • Actually, the oil industry is writing its own epitaph by failing to keep prices down. At the current price levels, oil is only just slightly cheaper than some alternate fuels. I've heard an estimate that if gasoline were $4 per gallon then hydrogen becomes competitive. If oil prices go up much more then suddenly some other fuel will become more attractive and the fuel wars will begin in earnest.

            Just as a sidenote, in Brazil the sales of ethanol-based (bi-fuel, actually) cars already surpassed the gasoli

            • in Brazil the sales of ethanol-based (bi-fuel, actually) cars already surpassed the gasoline-only ones.

              In the UK, most of the cost of fuel for cars is the very large taxes, and I think biofuels for cars are taxed the same as petrol/diesel - not that they're used much anyway. It's stupid, but...
      • But, well, if the city is Los Angeles, and the city is basically one huge smog-trapping bowl surrounded by mountains, and the smoke-belching hydrogen plant is on the other side of the mountains, then never mind the global CO2 levels, you've still made Los Angeles a significantly more pleasant place to live.

        I've found the best strategy is to move your emissions to New York. I don't know if it made Los Angeles a significantly more pleasant place to live, but things are certainly looking up for me.
      • (assuming you burn it with O2 and don't make any evil NOx byproducts)

        Your problem is with H2 made from hydrocarbons - so don't use them, fill the desert with solar cells and crack water, or better yet - make electricity and ship it to the H2 filling stations and crack the water there - I kn ow it's not economical now ... but hydrocabon prices are going up and solar cell prices and efficiencies are getting better all the time - one day those curves will collide and the deserts will 'bloom'

    • They don't count the emissions that may be needed to produce, compress and ship the hydrogen to the nearest gas station.

      Shipping them is easy. Run the truck that transports it with hydrogen.

  • Difficulty (Score:4, Funny)

    by someguy456 ( 607900 ) <someguy456@phreaker.net> on Saturday July 16, 2005 @11:43PM (#13085077) Homepage Journal
    "The process is analogous to stretching a slingshot from Earth to the nearest star, our sun, thereby building up a huge amount of energy when released," Taleyarkhan said. I sure hope their process can be done easier than their analogy!

  • Back to the Future (Score:4, Funny)

    by MindNumbingOblivion ( 668443 ) on Saturday July 16, 2005 @11:45PM (#13085082)
    So... that Mr. Fusion I ordered off of eBay will actually work?

  • Coffee (Score:2, Funny)

    by cyber_rigger ( 527103 )

    Hey, my coffee's getting cold.

    Would you mind nuking it for me.

  • One more evidence.. (Score:3, Informative)

    by William Robinson ( 875390 ) on Saturday July 16, 2005 @11:57PM (#13085121)
    of Cold Fusion [wikipedia.org], a technology that promises clean power in future (and prevent wars over oil). Just wondering why governments are so indifferent to Cold Fusion.
    • Because the cold fusion experiments so far have been extremely difficult, if not impossible, to replicate? Assuming something is happening, if the original experimenter can't pin it down enough to reproduce, it's kind of hard to justify funding for it. The DOE and others have flung a bit of money at it, though, and that's remarkable in itself.
    • DARPA is one of the principle funding sources for cold fusion research. Though this amounts to only about 25M (order of magnitude smaller than other US gov funding for hot fusion).

      More anything, it's the academic community generally, the NSF, etc that ridicules this work, not the government per se.

    • This is *NOT* cold fusion (Score:3, Informative)

      by zeux ( 129034 ) *
      RTFA:

      Researchers have estimated that temperatures inside the imploding bubbles reach 10 million degrees Celsius and pressures comparable to 1,000 million earth atmospheres at sea level.

      This is NOT cold fusion, this is sonofusion.

  • Quick DIY Guide to Fusion in your basement (Score:4, Funny)

    by Mr.G5 ( 722745 ) on Sunday July 17, 2005 @12:10AM (#13085159)

    Seems pretty easy to me:

    Step One: Build a sonoluminescence apperatus using an ocilloscope, a sine generator, audio amplifier, piezo transducers and spherical flask. Details here: http://www.physik3.gwdg.de/~rgeisle/nld/sbsl-howto .html [physik3.gwdg.de]

    Step Two: Build a neutron supply source, problalby most easily constructed is a farnsworth-type fusor: http://en.wikipedia.org/wiki/Fusor [wikipedia.org] (makes a great science project too)

    Step Three: Get some deuterium and dissolve it in acetone, place in your sonoluminescence apperatus and start tuning it to produce bubbles. Availible at your local scientific supply store.

    Step Four: Build your own neutron detector and confirm the bubbles are producing fusion: http://home.earthlink.net/~jimlux/nuc/ncount.htm [earthlink.net]

    Step Five: Become the envy of the neighbourhood as the only guy on your block with a nuclear fusion device in your garage! (to avoid police suspicion call it a magical glowing bubble maker)

    Step 6: Profit!

  • Source? (Score:3, Insightful)

    by nyri ( 132206 ) on Sunday July 17, 2005 @12:21AM (#13085189)
    Ok, let me ask this. Why is this on AScribe and not on Nature?

    I won't belive it until it's published on a peer reviewed journal.
    • Conceptually, this is one of those ideas that ought to work, but, when push comes to shove, more often seems to be a test of adherence to current orthodoxy rather than merit. Too often the reviewers seem to read the title in order to form their opinions rather than reading through the work and, if necessary, replicating the experiment. Eddington's response to Chandrasekar's work comes to mind.

    • I won't believe it until Netcraft announces it.

    • Re:Source? (Score:5, Informative)

      by jericho4.0 ( 565125 ) on Sunday July 17, 2005 @01:17AM (#13085351)
      It was published in Nuclear Engineering and Design [sciencedirect.com] in May (last article in list).

      5+ standard deviations against the control is interesting. Should be easy to reproduce. (or not).

  • cheaper source of neutrons? (Score:3, Funny)

    by slapout ( 93640 ) on Sunday July 17, 2005 @12:47AM (#13085263)
    That's right folks, come on down to Crazy Harry's Particle Superstore. Electrons! Protons! We've got neutrons for half the price of our competition! Mention this ad and get 10% off your next order of quarks!

  • methods of fusion detection (Score:3, Interesting)

    by icejai ( 214906 ) on Sunday July 17, 2005 @12:51AM (#13085283)
    It's interesting that the original professor's experimental results were discredited by the methods he used to detect fusion. First he detected neutrons, but then there was controversy about whether he was detecting fusion neutrons or png neutrons. Then, when he changed certain things, and still detected neutrons... everyone questioned whether or not they were background neutrons or fusion neutrons. Basically, they wanted to see the moment of neutron detection coincide with the moment of light creation down to the nanosecond (I think).

    Now, these guys are using other methods of detecting fusion by neutron energy levels, and tritium. I just hope that the levels they detected were WAY above the statistical normal amount of 2.5MeV neutrons and tritium in deuterized-acetone controls.

  • Doing H2 or H3 or H3-HE, will give off gamma. HE-HE will not. In fact, it only gives off alpha (electrons), which allow for direct harvesting without heat issues. So if they have this working for deuterium, I wonder if it is possible to get Helium to fuse?
    • HE-HE will not. In fact, it only gives off alpha (electrons),

      For one, electrons are beta, not alpha. Alpha's are helium nuclei, so if He-He really gave off alpha, you'd be right back where you started.

      And yes, it is possible to get He to fuse. Routinely happens in supernovas and even novas, and presumably if you slam two high energy beams of alphas together. The thing is, as you go up the table you get less gain on the amount of energy you put in.
      • You are right, I was meaning beta (just wasn't thinking or the fact that all my radiation classes and work were 25 years ago).

        What I was thinking was that rather than have a large reactor, it might be interesting to have a very small reactor in which we simply harvest the electrons directly. Nothing gets radioactive (well nothing is totally clean, so there will be some side reactions, but it will be as minimal as it gets). The initial product is non-radioctive, and so is the output. Of course, that depend
  • If you accelerate a bunch of nuclei fast enough at a bunch of target nuclei, all sort of stuff tumbles out of the rubble, including free neutrons, positrons and other alphabet particles (alpha, beta, gamma, etc.) This has been done and done again for decades in various labs and facilities around the world. This is a low cost particle accelerator you can fire up in your garage. Cool, but not novel.

    It is very cool to see researchers hacking atoms any way they can. Don't listen to the "experts". The peop

  • tabletop fusion has been around for decades (Score:5, Informative)

    by cahiha ( 873942 ) on Sunday July 17, 2005 @02:19AM (#13085511)
    You can get tabletop fusion with a TV high voltage supply, a glass bulb, some wire, and deuteriums gas. That's been known for decades and is used as a neutron source commercially. People build those things for science fairs. It's called the "Farnsworth Fusor [wikipedia.org]" (I know, in light of Futurama it sounds like a joke, but the fictional character was named after the real one).

    Why don't we all have flying cars, then? Because you can't get a net energy gain with the Farnsworth Fusor--it seems to be impossible in general to do so, the numbers just don't work out.

    Of course, even if you do make it efficient, it's not exactly "clean energy": even with so-called aneutronic fusion, a few percent of the fusion reactions will generate neutrons, which, for realistic power generation, results in a neutron flux that causes the power generation to be quite dirty. Not as dirty as fission--disposal should be easier--but don't expect something harmless you can just run in your basement.

    So, tabletop fusion isn't really anything impressive: there are probably lots of ways of getting fusion on your tabletop. The question is how you make it efficient enough to useful amounts of energy out of it. And cavitation seems no more promising there than inertial confinement in the Farnsworth Fusor. But maybe if enough people keep playing around with this, someone will get lucky and find something that works.

  • Rusi Taleyarkhan's fusion debunked by BBC Horizon (Score:5, Interesting)

    by wagdog ( 230574 ) on Sunday July 17, 2005 @06:56AM (#13086070)
    There was a BBC Horizon [bbc.co.uk] documentary on this nuclear fusion sonoluminescence phenomenon [bbc.co.uk] that casts strong doubt on the validity of previous work conducted by this researcher. The acid test for the occurence of fusion is the release of a neutron at the exact instant that the flash of light from sonoluminescence occurs. The Horizon team used a detector that can record the neutron releases at the required instant in time. After recreating Taleyarkhan's experiment according to his published journal papers, results were disappointing. None of the neutrons that were detected occurred at the same instant of any of the sonoluminescence flashes. The extra neutrons were explained away as originating from the emitter used to generate bubbles, or from external sources. No doubt rivals will challenge the statistically significant tritium claim. Tritium does occur naturally in significant quantities in any mass of heavy water (deuterium oxide).

  • Okay, what if this does pan out?

    presume: "Cheap nuclear fusion" power plants generate electrical power for equivalent of 1 cent / KWh.

    * Coal usage drops to drastically (still used in off-grid locations)
    * Oil production drops drastically;
    * Natural gas still produced as portable energy source;
    * someone figures out electrical generation of methane or propane (electricity + carbon + water) and cars start using that instead of OPEC oil;
    * OPEC countries have vast revenue drops, destabilize, and undergo drastic

  • hydrosonic pumps (Score:2, Interesting)

    by RusDavies ( 900439 )
    So what would happen if you used deuterated acetone in a cavitaion device such as the hydrosonic pump? (see, http://www.hydrodynamics.com/product_pics.htm [hydrodynamics.com])

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