Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Science Technology

Team Confirms UCLA Tabletop Fusion 354

Posted by ScuttleMonkey from the doc-oc-not-available-for-comment dept.
An anonymous reader writes "A team of New York physicists has confirmed that a tabletop contraption made at UCLA does in fact generate nuclear fusion at room temperatures, using pairs of crystals and a small tank of deuterium. But unlike less reliable reports back in the 1980s, there's no talk this time of producing endless supplies of power. Rather, the technology could lead to ultra-portable x-ray machines and even a wearable device that could provide safe, continuous cancer treatment."
This discussion has been archived. No new comments can be posted.

Team Confirms UCLA Tabletop Fusion More

Team Confirms UCLA Tabletop Fusion

Comments Filter:

  • Key Application Overlooked (Score:5, Informative)

    by TripMaster Monkey ( 862126 ) * on Monday February 13, 2006 @12:39PM (#14708072)

    From TFA:
    Rather, the most immediate application may come in the form of a battery-operated, portable neutron generator. Such a device could be used to detect explosives or to scan luggage at airports, and it could also be an important tool for a wide range of laboratory experiments.
    I'm surprised that the article didn't go into more depth on the explosives detection angle, as a neutron generator is an excellent method for detecting fissionable material, and I'm sure the folks over at Homeland Security would like a better way to guard against nuclear devices being smuggled into our country.

    For more info on neutron generators and their possible application in fissionable materials detection, please look here (PDF warning) [latech.edu].

    • Re:Key Application Overlooked (Score:5, Interesting)

      by NitsujTPU ( 19263 ) on Monday February 13, 2006 @12:54PM (#14708270)
      Everyone's overloaded on hearing about people blowing up airplanes. Hunting down terrorists is the depressing fact harped at us constantly in all directions. A two sentence mention in the article is about all that is really warranted, don't you think? Perhaps they should have said "nukes," or "fissionable material." Fissionable material doesn't really hit home for most people though. Nukes sounds outlandish. Explosives is a bit too broad.

      Not being a scientific paper, the details of the procedure aren't germaine to the article.

      Eh, it's close enough, right?
    • Of course such devices are only of limited use to DHS. They presume that the potential terrorist must smuggle in his or her device through an airport in the United States.

      The reality is that the easiest way to smuggle in a nuclear device would be to get it first into Canada or Mexico. There are stretches of border there that go on for miles that are patrolled by a dozen or fewer officers -- often not even U.S. Border Patrol, but instead local law enforcement agencies that lack the training to properly pro
    • There's one thing I'm wondering, though.

      Assuming terrorists build a working nuclear device, why would they want to smuggle it into the country? Surely, detonating it near the coast would work just fine.

      • Re:Key Application Overlooked (Score:5, Informative)

        by lgw ( 121541 ) on Monday February 13, 2006 @02:19PM (#14709382) Journal
        Modern nuclear weapons are around 1 MT, usually a bit less, as that's the optimal size for a weapon you can target accurately. The larger nukes of old were designed to crack silos with a near miss, were extremely expensive for their mission, and were taken out of service long ago. If a terrorist gets a nuclear weapon, it's either going to be a sub-MT military weapon, or a quite a bit smaller "home made" fission only device (modern nukes are pretty sophisticated fusion-pumped-fission devices).

        Let's do the math [nuclearweaponarchive.org]. A 1 MT nuke detonated at optimal blast height will knock down residential structures at a radius of 10 km, more solid buildings at 7 km, and at 5 km knock down reinfored buildings and kill people outright from the blast (and all other effects, such as high doses of radiation, have smaller radii). A surface blast would have a far smaller effect. The only real point of a surface blast is to generate radioactive fallout (an air blast generates surprisingly little, though it would still hinder clean-up and rebuilding).

        So yes, in theory, a terrorist with a high-quality military nuke (let's imagine a few were sold out of the old USSR armory, and somehow still worked today (the tritium would have to be replaced, which is quite technical, but lets imagine a scientist came with the bomb)) could sit a couple of kilometers off the coast and destroy some structures along the coast. Good for psycological impact, but not much else, and insanely expensive to carry out. A 50 kt fission bomb, a far more likely scenario for a terrorist, would have less than 40% of the blast radius of the high quality military bomb, and would probably need to be within 1 km to be effective.

        A surface blast over *land* is what a terrorist wants, because the radioactive fallout would cause a world of hurt. You'd get very little of that even 1 km off the coast, and even a ship at a dock would produce far less fallout than a bomb 1 km inland. It's *definitely* worth checking for nukes at ports of entry: the threat just goes down very fast as the bomb moves away from land.
    • guard against nuclear devices being smuggled into our country.

      Ahem... or out of the country. Keeping tabs on one of the worlds largest nuclear stockpiles is a major, fulltime job and not one to be taken lightly.

    • Re:Key Application Overlooked (Score:5, Insightful)

      by Temkin ( 112574 ) on Monday February 13, 2006 @01:01PM (#14708364)

      You missed the other key application... A cheap ready supply of neutrons is exactly what you need to transmute elements... Sadly, this includes the most common element transmutation carried out by mankind to date... U-238 to Pu-239. Cheap tabletop neutrons means cheap Pu-239 without the cost & mess of having a breeder fission reactor...

      This will make non-proliferation all the harder. :(

      • Re:Key Application Overlooked (Score:5, Insightful)

        by DerekLyons ( 302214 ) <fairwater.gmail@com> on Monday February 13, 2006 @01:19PM (#14708577) Homepage
        You missed the other key application... A cheap ready supply of neutrons is exactly what you need to transmute elements... Sadly, this includes the most common element transmutation carried out by mankind to date... U-238 to Pu-239. Cheap tabletop neutrons means cheap Pu-239 without the cost & mess of having a breeder fission reactor...

        This will make non-proliferation all the harder. :(

        Not really. You still have to mine and purify the uranium (a decidely non trivial task), then you have to bombard (literally) tons of U-238, then you have to extract the Pu from the U (extremely non trivial). Or, in short, while you avoid the messy step of a reactor - you still have a large and difficult (and messy) industrial process. (I.E. nation state level, not terrorist groups.)

        • Or, in short, while you avoid the messy step of a reactor - you still have a large and difficult (and messy) industrial process. (I.E. nation state level, not terrorist groups.)

          Which is bad enough. The question is, does this take it from being a nation state level threat confined to a dozen powerful players, down to a nation state threat within reach of nearly every nation harboring the desire?

          You're also assuming that some kind of bomb device is the end goal. This doesn't need to be the case. You can

          • Or, in short, while you avoid the messy step of a reactor - you still have a large and difficult (and messy) industrial process. (I.E. nation state level, not terrorist groups.)

            Which is bad enough. The question is, does this take it from being a nation state level threat confined to a dozen powerful players, down to a nation state threat within reach of nearly every nation harboring the desire?

            No, it does not. As I pointed out - you still need a substantial industrial infrastructure. (Unless you are c

        • The article is a bit thin about quantitative stuff, but if these devices really are cheap and they produce enough neutrons, they should prove quite practical for U238 or Thorium-to-fissile-Uranium transmutation. A lot also depends on their efficiency, and also on access to large quantities of Deuterium (not trivial).

          Right now, there are two practical ways to make material for a bomb: reprocess spent fuel from a nuclear reactor, or centrifuge the hell out of UF6 to produce highly enriched Uranium. Both of

        • Re:Key Application Overlooked (Score:5, Interesting)

          by aminorex ( 141494 ) on Monday February 13, 2006 @02:44PM (#14709669) Homepage Journal
          No, it does not require tons of U-238 to produce supercritical masses of Pu-239. Less than a ton will do very nicely. What it does require is a fair amount of Tritium. D-D fusion neutrons are too slow. D-T fusion neutrons are perfect for the production of Pu-239. Separating the Pu from the U is trivial. It is a purely chemical process. I did this with an IEC fusor using surplus DU from a 747 counterweight. Using the fusor it would have taken gigawatts of electric power to produce a critical mass in less than a decade, and the process was impractical for weapon production. I don't know enough about the new process to comment, but if it improved the electrical efficiency by a couple of orders of magnitude, it would result in a viable process.
      • Um don't you need protons for that also? Adding neutrons would just create isotopes...

        • Um don't you need protons for that also? Adding neutrons would just create isotopes...

          No. You have to overcome the charge of the protons to get them to enter the nucleus. If it were easy to get protons to enter a nucleus, we would have had fusion decades ago.... Of course the universe wouldn't exist as we know it, but that's not really germane to the discusison. Neutrons, having no charge at all, fly right in and collide, unimpeded by the electron cloud or the protons.

          If I remember correctly, there's a

        • No, you don't need protons. What happens when a neutron hits a U-238 nucleus is that one of the neutrons is converted into a proton, and an electron is emitted, carrying off the extra negative charge. This leaves a Pu-239 nucleus. Sorry, I don't know how that maps to events on the quark level.

          SpeakerToManagers
    • Seriously Trip, you are trying waaay to hard.
    • Sounds like this could be used to generate seeds for a portable version of the Radioactive Random Number Generator [slashdot.org]

  • Tabletop fusion (Score:5, Funny)

    by Bit_Squeezer ( 824571 ) on Monday February 13, 2006 @12:41PM (#14708099)
    Crystals and holy water?

  • I predict the #1 application for this technology (Score:2, Funny)

    by Anonymous Coward
    ...will be for mood rings that give you finger cancer.

  • Interesting (Score:4, Informative)

    by hey! ( 33014 ) on Monday February 13, 2006 @12:42PM (#14708119) Homepage Journal
    It's quite an accomplishment. However, as the article noted, they don't mention even the remote future possibility of creating a self-sustaining reaction. So I'm assuming that there is no way even in principle this technology could be scaled to yield more power than it uses.

    • Re:Interesting (Score:5, Informative)

      by Vellmont ( 569020 ) on Monday February 13, 2006 @12:54PM (#14708279) Homepage

      So I'm assuming that there is no way even in principle this technology could be scaled to yield more power than it uses.


      From the sound of what's going on, I think that's correct. The thing about a confined fusion generator is that it works through having the plasma at enormous temperatures. At these high temperatures the particles are slamming into each other at high speed, occasionally so hard they fuse together. This fusion itself produces more heat, so there's a feedback loop that's sustaining the reaction. This device sounds like it works through just accelerating particles with an electric field to high speeds, and then smashes the particles into one another. I don't see any potential for feedback here, so a sustained reaction seems unlikely.

  • Better than two (Score:5, Funny)

    by DigitlDud ( 443365 ) on Monday February 13, 2006 @12:42PM (#14708120)
    "Our device uses two crystals instead of one, which doubles the acceleration potential," says Jeffrey Geuther

    Yeah well, now I'm going to use three!

  • Room temperature? (Score:3, Interesting)

    by sploxx ( 622853 ) on Monday February 13, 2006 @12:43PM (#14708126)
    Although the device as a whole may be at room temperature, the region where the fusion reactions occur is at a much higher temperature (10^6K or similar) - as it is needed for fusion.

    Speedy particles smashing into each other have a lot of kinetic energy in the center of mass inertial system. This is nothing different than 'heat'.

    • Re:Room temperature? (Score:2, Informative)

      by pclminion ( 145572 )
      Speedy particles smashing into each other have a lot of kinetic energy in the center of mass inertial system. This is nothing different than 'heat'.

      Wrong. Heat is random motion. If simple kinetic energy was all it took to have heat, then any gas cloud out in space with a large velocity relative to us would be extremely "hot." But we all know intuitively that things do not change temperature just because they speed up. The air in a moving car is not hotter than the air in a parked car. Heat is the random

      • I don't see what point you are trying to convey here. The energy translates into heat, are you saying that a bullet hitting a metal plate doesn't translate some of that kinetic energy into heat? In this case, the particles aren't being shot into a void, like your gas cloud in space example. Take a nuclear bomb for example, the neutrons are bouncing all around within a beryllium sphere, the thing explodes into a fireball. What is the difference?

        No really, what is your point? I don't claim to be a genius on

        • The energy translates into heat, are you saying that a bullet hitting a metal plate doesn't translate some of that kinetic energy into heat?

          It does, but that energy wasn't heat BEFORE the bullet hit the target. If an object being in motion was equivalent to heat, then the temperature of objects would depend on their relative velocities to us. That is clearly an absurd concept.

          No really, what is your point?

          He asserted that because the colliding particles have lots of kinetic energy, they are therefor

      • Re:Room temperature? (Score:4, Insightful)

        by sploxx ( 622853 ) on Monday February 13, 2006 @06:29PM (#14712033)
        [[Speedy particles smashing into each other have a lot of kinetic energy in the center of mass inertial system. This is nothing different than 'heat'.]]

        Wrong. Heat is random motion.

        Well, the 'smashing' part I explicitely stated accounts for the thermalization.

        If simple kinetic energy was all it took to have heat, then any gas cloud out in space with a large velocity relative to us would be extremely "hot." But we all know intuitively that things do not change temperature just because they speed up. The air in a moving car is not hotter than the air in a parked car. Heat is the random motion of particles with respect to each other .
        No, not 'respect to each other', in respect to the center of mass, as I wrote. Heat is the average kinetic energy of particles (in classical statistical mechanics).

        The collision of a few particles doesn't qualify.
        And why not? Care to explain?

        When gas quickly depressurizes, it cools down. Ever wonder why? It's because as the gas escapes, the particles which are near each other tend to all move in the same direction (outward) and thus their random motions with respect to each other are decreased. Thus, the temperature drops.
        Yes, the temperature drops. But the gas still carries the same amount of heat (transportation by photons excluded). Smash two nuclei, they interact, a hot ball of reaction products results and cools down as the particles move away from each other according to a law similar to pV=NRT.
        The temperature drops, the amount of heat in this ensemble of molecules/atoms/particles stays the same.

        Or consider how a rocket nozzle works by focusing the molecular motions in a particular direction (by forcing the gas through a small opening to increase the pressure and then into a cone to suddenly decrease it), thereby converting the high pressure and heat of the exhaust gas into directed kinetic energy.
        What do you want to say with this paragraph?

        Learn more before making these kinds of proclamations.
        Sigh. Bold and derogatory statements like this activate /.'s groupthink and your post gets moderated higher than mine. ("He's louder so he knows better...") I infer from your arrogance that you probably have a PhD in theoretical physics - but you should've learned some communication skills, too :-)
    • You're missing the point. The byproduct of this reaction is heat, not the other way around. Previous fusion devices use heat and/or pressure from magnetic fields, or lasers, or other methods to cause fusion. This does not.

  • What? (Score:5, Funny)

    by Odin_Tiger ( 585113 ) on Monday February 13, 2006 @12:44PM (#14708134) Journal
    "application may come in the form of a battery-operated, portable neutron generator"

    Wait, what? We finally got cold fusion, but 'batteries not included'?

    • Re:What? (Score:2, Informative)

      by massivefoot ( 922746 )
      No, we do not have cold fusion. This isn't a power source at all (i.e. over all the process is endothermic), we just have a small "neutron-making-machine".
      • It is cold. It is fusion. It is cold fusion. Then again, it is quixotic to argue with anyone who does not accept FOPL.

  • Key chain application overlooked (Score:5, Funny)

    by SEWilco ( 27983 ) on Monday February 13, 2006 @12:46PM (#14708164) Journal
    Also overlooked is the forthcoming businesses selling crystal pendants and key chains which "fight" cancer and provide other beneficial effects.

  • Licensing... (Score:5, Funny)

    by lukewarmfusion ( 726141 ) on Monday February 13, 2006 @12:46PM (#14708167) Homepage Journal
    I will now take bids on licensing my screenname.

  • Incredible (and im not talking about the article) (Score:5, Insightful)

    by MrTester ( 860336 ) on Monday February 13, 2006 @12:52PM (#14708250)
    Its amazingly clear that not only have few of you RTFA, most have not even gotten past the title before you threw out a post.

    Its a whole 4 sentences which make it clear that this is NOT a power source, and half the posts are talking about its potential as a power source.

    Now if I could just find a way to bottle the power of human stupidity...

  • Darn (Score:4, Funny)

    by Nom du Keyboard ( 633989 ) on Monday February 13, 2006 @12:52PM (#14708255)
    Darn, now I have to go sell my palladium stash that I have put away just in case someone actually made it work the old fashioned way.

  • could provide safe, continuous cancer treatment. (Score:3, Insightful)

    by JustNiz ( 692889 ) on Monday February 13, 2006 @12:54PM (#14708271)
    Yeah beacuse everyone knows being continuously bombarded with X-Rays is safe.

  • 200,000 Electron Volts (Score:5, Funny)

    by sarlos ( 903082 ) on Monday February 13, 2006 @12:55PM (#14708282)
    But can it crank out 1.21 gigawatts?
  • Are we talking x-ray laser sort of technology? Is 200,000 electron volts enough to do significant damage? Surface burns and radiation poisoning?

  • Jerks (Score:3, Insightful)

    by breckinshire ( 891764 ) on Monday February 13, 2006 @12:58PM (#14708319) Homepage
    Is it just me, or did this article make the Renselaar folks seem like smug jerks? As in, "Yes, not only did we prove that it works, but we proved that we can do it a lot better than those toking, surfing, hippies!"

  • Get the paper here (Score:5, Informative)

    by Anonymous Coward on Monday February 13, 2006 @12:59PM (#14708330)
    The paper [rpi.edu].

  • tabletop fusion (Score:3, Insightful)

    by penguin-collective ( 932038 ) on Monday February 13, 2006 @01:01PM (#14708356)
    Tabletop fusion has been in use for quite some time. This device looks like it's a little bit simpler than the Farnsworth fusor, but it's an incremental improvement, not a radical breakthrough.

    The breakthrough would come should anybody ever figure out how to break even energetically in a tabletop fusion device, and I think it's quite possible that that will happen sooner or later.

  • question (Score:2, Funny)

    by kevin.fowler ( 915964 )
    What if the crystal cracked?

    http://www.imdb.com/title/tt0083791/ [imdb.com]
  • Tabletop fusion is hard. You have to be rolling 20's to get it started.
  • "wearable device that could provide"

    Similar to a backpack capable of firing a ectoplasmic containment stream? Or portable power supply for a flux capacitor?
  • They could use it to make a "suitcase" neutron bomb! Sure, it might take hundreds of hours per individual to dispatch them, but terrorists have time on their hands!

  • From TFA: "Our device uses two crystals instead of one, which doubles the acceleration potential,"

    Ladies and gentleman, we have found di-lithium crystals!

  • If they think practical applications in medical imaging and airport scanning are in the foreseeable, commercial future... well, if you can produce enough power to do that, you certainly can produce enough power to injure people.

  • Ob. Ghostbusters Quote (Score:3, Funny)

    by GJSchaller ( 198865 ) on Monday February 13, 2006 @02:25PM (#14709459) Homepage
    Dr Ray Stantz: You know, it just occurred to me that we really haven't had a successful test of this equipment.

    Dr. Egon Spengler: I blame myself.

    Dr. Peter Venkman: So do I.

    Dr Ray Stantz: Well, no sense in worrying about it now.

    Dr. Peter Venkman: Why worry? Each one of us is carrying an unlicensed nuclear accelerator on his back.

  • Could Fusion/Fission Hybrids be made? (Score:3, Interesting)

    by DumbSwede ( 521261 ) <slashdotbin@hotmail.com> on Monday February 13, 2006 @02:58PM (#14709805) Homepage Journal
    There have been a number of discoveries recently about how to generate neutrons from fusion albeit at a large energy loss.


    What I'm wondering is whether this could be used to create a hybrid device that blast fissionable material with reaction initiating neutrons, rather than balance the fissionable material on the knife's edge of criticality. If so then fission reaction would stop immediately upon loss of initiating neutrons from the fusion source and you have a much safer nuclear reactor design. Could this also be used to burn our existing stockpiles of waste, and if not practical with these neutron sources, could future more efficient fusion reactors be used to extract additional energy from nuclear waste while consuming and disposing of it at the same time?

Slashdot Top Deals

"The vast majority of successful major crimes against property are perpetrated by individuals abusing positions of trust." -- Lawrence Dalzell

Close