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Power Technology

Ask MIT Researchers About Fusion Power 318

Nuclear fusion power is the process of fusing light nuclei together to release energy, and ultimately, to put electricity on the grid. Today, we have six researchers from MIT's Plasma Science and Fusion Center here to answer your questions about fusion power, tokamaks, and public support and funding in the U.S. for this research. The Obama Administration's budget request for fiscal year 2013 is paying for the U.S. share of ITER construction out of the domestic program, starting with the closure of the MIT fusion lab. The interviewees are ready to answer technical and policy questions, so don't be shy! And, as always, please break unrelated questions into separate posts. Read on for information about the researchers who will answer your questions.
Dr. Martin Greenwald is a Senior Scientist and Associate Director of the MIT Plasma Science and Fusion Center. His experimental work focuses on turbulence and transport, density limits, and pellet fueling of magnetically confined plasmas. More recently, Dr. Greenwald has been heavily involved with data management, computation, simulation, networks, and remote collaborations for fusion research.

Professor Ian Hutchinson is interested in plasma control in tokamaks, as well as spatially resolved measurements of the radiated power coming from the plasma. He is the author of the standard fusion textbook Principles of Plasma Diagnostics. Prof. Hutchinson also works on particle-in-cell simulations of astrophysical and laboratory plasmas.

Assistant Professor Anne White researches turbulence phenomena on the Alcator C-Mod tokamak, developing new diagnostics to resolve the small fluctuations which cause energy and particles to leak out. She is the recent recipient of the U.S. Department of Energy Early Career Award.

Professor Dennis Whyte pursues research into plasma–material interactions; that is, the way the hot plasma in a magnetic fusion reactor interacts with the surrounding solid materials walls. His team is also developing novel diagnostics for fusion nuclear science, which is critical as fusion reactors start producing power (and neutrons) over long periods of time.

Nathan Howard and Geoff Olynyk are Ph.D students on the Alcator C-Mod project. Nathan, who is in the final year of his studies, studies turbulent transport phenomena experimentally and through simulation. Geoff, in his fourth year, is working on disruption mitigation, which is a way to quickly and safely shut a tokamak plasma down in a few thousandths of a second.
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Ask MIT Researchers About Fusion Power

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  • Polywell fusion (Score:5, Interesting)

    by mknewman ( 557587 ) * on Thursday March 22, 2012 @10:55AM (#39440529)
    What do you think of the efforts at [] and [] ? They seem to be making real, measurable and open results but the mainstream physics community seems to ignore this progress.
  • by Soruk ( 225361 ) on Thursday March 22, 2012 @10:57AM (#39440549) Homepage

    > fusing light nuclei together

    Light nuclei? They're just photons.

  • by eldavojohn ( 898314 ) * <(eldavojohn) (at) (> on Thursday March 22, 2012 @10:57AM (#39440555) Journal
    Not to raise any fears -- rather out of genuine curiosity -- what happens when the magnetic fields that hold the 90,000,000 degrees Celsius plasma in place fail or loser power on the Alcator C-Mod? I understand it's probably in prototype mode but what sort of safety advantages or disadvantages do Alcator C-Mod designs offer over conventional large scale designs? Does the plasma come into contact with the toroidal super conducting coil? Then what?
    • by benjfowler ( 239527 ) on Thursday March 22, 2012 @11:18AM (#39440813)

      Ultimately, you'd have to ask an expert -- but I do know that there is a fairly substantial first wall between the plasma and the coils (and just as well -- a quench on a machine the size of ITER would truly be something to behold). Not sure what you mean by Alcator C-Mod being 'unconventional' -- were you referring to the superconducting magnets, as opposed to copper ones?

      Particularly on large machines, during disruptions, there is potential for serious damage to the first wall from heating, runaway electrons, and substantial mechanical forces. Disruption mitigation is considered a priority for ITER, because the problems get worse for large machines, especially research machines not designed with the duty cycles of actual, real power plants.

      The plasma DOES come in contact with the 'divertor', which is a part of the interior of the reactor where the cool outer edge of the plasma outside the last set of closed field lines is drawn out over a large surface area to trap and remove the helium 'ash' and other contaminants from the plasma. The plasma is held tightly within the closed magnetic field lines within the torus, and only the 'scrape off layer' ever comes anywhere near the walls. This is key to performance, as performance is closely related to purity (contaminants wastefully radiate away energy).

      • But do you contain the exotic particles or push them into a parallel universe?
      • The plasma DOES come in contact with the 'divertor', which is a part of the interior of the reactor where the cool outer edge of the plasma outside the last set of closed field lines is drawn out over a large surface area to trap and remove the helium 'ash' and other contaminants from the plasma.

        Actually the plasma never comes into contact with the divertor The divertors are at the bottom of the torus where the field lines are twisted and the contaminants can be pulled off. There is no plasma here but the heat of the reaction is still very much present.

        The plasma never comes into contact with anything as doing so means it would cool enough to lose the reaction

  • by monsted ( 6709 ) on Thursday March 22, 2012 @10:59AM (#39440577)

    When will fusion power my house?

    • 2050 (Score:4, Funny)

      by Anonymous Coward on Thursday March 22, 2012 @11:09AM (#39440703)

      just skip the Microwave Power Plant in 2020

    • Expanding on this: (Score:5, Interesting)

      by Anonymous Coward on Thursday March 22, 2012 @11:28AM (#39440987)

      Could you break down the various barriers/bottlenecks to the introduction of commerical fusion?

      What are the technical problems in the state of the art, what other factors (political, economic, etc.) do you see at play?

      How do you and your labs collaborate with others, and how is technology transferred? Is there much international cooperation?

      Are there policy communities (China, India?) that might be more primed for the introduction of fusion technology into their grids than in North America? What would need to happen for North America to start using fusion?

      I have many more questions, but those are the ones that popped into my head first. This is such a great opportunity -thank-you for taking the time today!

    • or my DeLorean?

    • When you get your flying car?

  • by Bucc5062 ( 856482 ) <bucc5062 AT gmail DOT com> on Thursday March 22, 2012 @11:03AM (#39440623)

    As a non-scientist, what are the biggest stumbling blocks for effective fusion reaction? is this truly throwing money down the energy hole, or are there verifiable, measurable benchmarks that lead us from one point to the next. Something like, we got x to work, now we need y, when we get y, we get z and then we get fusion. Is it technology holding us back, politics, or the science?

    • by Dynetrekk ( 1607735 ) on Thursday March 22, 2012 @11:10AM (#39440719)
      Fusion reactors generate enormous amounts of neutrons, which interact only weakly with matter. Making a reactor casing that can withstand the radiation damage and collect the heat for useful purposes (power generation, desalination of water, heating for industrial processes etc.) for long enough is extremely hard. This is expected to be the ultimate limit to how well fusion power can work. I don't have a citable source, but I got this from a talk at CERN by the guy in charge of the ITER [] project.
      • Mod parent up. Advanced materials are a BIG issue for future machines. Everyone else recognises this, and are trying to find ways to get a head start on the problem now, instead of in 20 years time.

      • by tragedy ( 27079 )

        Do neutrons react weakly with matter? That's kind of news to me. In fact, the radiation damage that you mention would seem unlikely to happen if the neutrons interact weakly. Are you sure you're not thinking of neutrinos with that first line? The rest of the post seems to make sense. There are some fusion reactions which don't directly produce neutrons, such as hydrogen-boron-11, but even those would almost certainly produce some neutrons through secondary effects.

        • I'm 100% sure. Neutrons are uncharged and interact very weakly with matter compared to electrons and protons. Hence, they penetrate deeply into any material. We're talking on the order of magnitude of meters, though. Neutrinos, however, will interact only once per several thousand light years when passing through solids - that's a whole different business.

          tl;dr: Neutrons interact weakly enough to penetrate, but strongly enough to be annoying.

          • by tragedy ( 27079 )

            I see what you mean about nuetrons, but, relative to other things that are said to interact weakly, neutrons seem to interact pretty strongly. When physicists talk about things interacting weakly, they generally seem to be talking about things that are much harder to detect than neutrons which is what led to my objection.

            • Neutrons interact through the strong and weak forces, but not the electromagnetic forces. The weak force is, in fact, weak, and the strong force is strong, but really short-range only. Basically a neutron has to run smack into an atomic nucleus to "feel its presence", whereas a proton will hit a wall of electrons (both protons and electrons are charged) when it enters a material. Thus a neutron can very well interact strongly (in any meaningful sense of the word, both in physics-speak and regular-english-sp
  • NIMBYA (Score:5, Interesting)

    by GeneralTurgidson ( 2464452 ) on Thursday March 22, 2012 @11:03AM (#39440625)
    How do you explain the safety/benefits of fusion to a generation of people terrified of nuclear anything?
    • Not In My Back Yard ... Asshole?

      • I don't know how it became trendy, but frankly I think if people don't want things in their back yard asshole, then they shouldn't have put an asshole in their back yard.

    • Difficult becuase the people against fusion (most likely for traditional power generation) simply have to spread FUD and the people start freaking out. Its like the Superconducting Super Collider; people threw some FUD out there claiming it would create a black hole, even though the physics clearly showed that was impossible, remember that? The fact is that people are going to be scared of it until its in production and delivering the power.
      • The fact is that people are going to be scared of it until its in production and delivering the power.

        It should, perhaps, be noted that people are still terrified of fission plants, in spite of them being "in production and delivering the power"....

  • by gyepi ( 891047 ) on Thursday March 22, 2012 @11:04AM (#39440637) Homepage
    Are there any good guesstimates on how small a tokamak-based fusion reactor (which produces more energy than consumes) can become? Theoretical limitations on size of the reactor would have obvious implications for pragmatic issues. AFAIK there is very little limitation on how small fission-based reactors can get.
  • by Erich ( 151 ) on Thursday March 22, 2012 @11:05AM (#39440661) Homepage Journal
    ITER is a hugely expensive project, and won't produce a commercially viable power generation system.

    In a lot of areas where research is done on things which don't work yet -- rockets, bridges, transmission systems, etc -- there's a general idea of how things might be able to "scale up" to meet the goals.

    Is tokamak fusion really in sight of being commercially viable source of energy? If we need unobtanium to make a commercially viable reactor, wouldn't it make sense to wait until the materials are viable before making even larger tokamaks? What do we learn from making these new, bigger, more expensive reactors?

    Or are we trying to build ever-bigger spark gap transmitters as a way to make radio better? Maybe we should look at other schemes?

    Or, alternatively, we know of a nice, large, gravity-fed fusion reactor fairly nearby, is the engineering simpler to harness energy from that on a large scale?

    • I wouldn't call ITER cheap either, but it's an international project (and the Chinese aren't locked out, as is currently the case on the ISS) and the cost is distributed over several decades and billions of people. Germany's share is on the order of $2bn over 35 years. That's $0.70 per capita per year. Much less than a lottery ticket, but with much better chances than 1 in 140mio for winning the jackpot.

  • Careers in fusion (Score:5, Interesting)

    by benjfowler ( 239527 ) on Thursday March 22, 2012 @11:06AM (#39440663)

    As practicing researchers, can you tell us about the health of the pipeline of young researchers coming into the field? Is there a glut of trained physicists at this stage, or is there still a need for trained specialists to enter the field, especially with ITER and follow-on machines coming online in the next couple of decades?

  • IEC's / Fusor (Score:5, Interesting)

    by claytongulick ( 725397 ) on Thursday March 22, 2012 @11:08AM (#39440681) Homepage

    Why aren't IEC reactors based on Farnsworth's designs taken more seriously? From what I understand, IEC's have been more effective at producing fusion, and they are cheap to build. People even build them in the garage []. From everything I've read, no one really takes the "fusor" seriously in the fusion science realm, and it's considered a dead line of inquiry. I've never understood why.

    • Re: (Score:3, Informative)

      by Anonymous Coward

      I spent my fusion time at NBTF (Neutral Beam Test Facility at Berkeley). Fusor type stuff is really easy and the plasma discharge is great to watch (got lots of photos). Making a few D-D fusion neutrons is easy. Making enough to be useful requires a larger machine. After a bit of quality slide rule time one ends up with a REALLY BIG tokamak or mirror machnine (MFTF, my project).
      Sorry, fusor type setups are for show. I did work with a fusor like project afew years ago that might work as a neutron source, b

    • "Good news everyone!"
  • by Tragek ( 772040 ) on Thursday March 22, 2012 @11:08AM (#39440685) Journal

    Is fusion power going to be feasible in the next 60 years (extrapolating my expected lifespan)?

  • by Tragek ( 772040 ) on Thursday March 22, 2012 @11:10AM (#39440713) Journal

    Do you think a program of the size of the Apollo program could kickstart fusion to general availability? Or would a rather smaller program suffice?

  • Patents (Score:5, Interesting)

    by Anonymous Coward on Thursday March 22, 2012 @11:10AM (#39440721)

    Will patents get in the way of your research?

  • by Iskender ( 1040286 ) on Thursday March 22, 2012 @11:11AM (#39440733)

    From the outside fusion research looks like a desperate field that's always struggling with its fundamental research/engineering questions. I know more than most laymen: I know the reactions work, I know the sun is powered by (very slow) fusion, I know fusion reactors have produced at least around 50% return on the electricity put in. Still, it feels like it's possible it'll never work, even knowing that difficult problems take time to solve.

    This is the outside view. What does the future of fusion look like when you experts look at it from the inside? Does it look like a gamble? Or does it look more like "just give us proper funding and we'll give you your reactor."?

  • by Anonymous Coward

    The late Dr. Bussard of EMC2 [emc2fusion. org] claimed that the fundamental concepts of Tokamak fusion did not provide a platform for cost-effective positive-return power reactors. With the enormous ITER project reactor still not expecting positive return, at what point, if ever, will Tokamak research benefit the power grid?

  • by petes_PoV ( 912422 ) on Thursday March 22, 2012 @11:15AM (#39440785)
    Given $1Tn, the pick of the best brains in the world to work willingly on the project, a large enough location away from any and all governmental regulation and every facility you could ever need - WHEN WILL IT BE COMMERCIALLY AVAILABLE?
    • by hattom ( 1876314 )
      I was told that a similar question was asked of someone in the UK fusion programme about 2 or 3 years ago by the director. The guy went away and did some sums to answer the question: Given the money to build it now, how well could a fusion plant be constructed, and what would be the cost of electricity produced. His answer was something like as follows: To build a power plant now would require working around the current problems (such as ELMs) by creating a machine to run in L-mode (low confinement mod
  • Thanks for taking the time to do this, I went to a lecture given by someone who worked on the JET reactor and it was fascinating.

    Given that fusion creates (shorter-lived) nuclear waste, the cost of it is unknown and the timeframe is unknown, how can you justify the relatively large amounts of money going towards fusion research reactors when so little goes towards fission research reactors?

    I know that the economics of larger reactor = more economical are well known with tokomaks. Does this mean you ha
    • Oh and how does it feel to be working on something which you probably will never see come to fruition in your lifetime?
    • by tragedy ( 27079 )

      Since fission power is actually a (theoretically) commercially successful industry, one could expect funding for fission research to be more readily available from private sources. More speculative, but still potentially valuable, research like fusion is more the domain of public funding. Then, when the public funding has produced something that could be commercially viable, the private interests get to swoop in and the ones with the right connections get patents on everything.

  • by gestalt_n_pepper ( 991155 ) on Thursday March 22, 2012 @11:20AM (#39440835)

    I understand that long term, we would want fusion, but we face increasing energy problems over the next 50 years and severe energy problems before 2100. Wouldn't it make sense to allocate research and development resources to something that we know works?

  • But about capturing the power? Are we generating heat that will drive steam turbines?

    What schemes to capture and harness the power exist?

    • A tokamak power plant would use a thick wall, called a blanket, which slows the fast neutrons from the reaction, and using the resulting heat to heat a working fluid, driving a turbine. Note that this hasn't been demonstrated yet though -- they'll do this on ITER.

      • by majanz ( 2601225 )
        So it'll just be like Fission, Gas or Coal? Provide a heat source to boil water to drive a turbine? How's that going to power my starship? Is there anyway to use something like an MHD generator ( to convert the fusion plasma directly into energy?
    • by tp1024 ( 2409684 )

      JET almost broke even in 1997 - they got Q=0.7. Theoretically, they could achieve Q=1, but what's the point in that? The turbine has an efficiency of about 33% (give or take), so you'd need Q=3 just for steady state operation without further losses. Economical power generation will need more than this, on the order of q=20. However it's not as bad as it sounds. The plan is to try to achieve plasma ignition at ITER (which is Q hitting infinity - the fusion reaction sustaining itself, needing no outside heati

  • Dense Plasma Focus (Score:5, Interesting)

    by mbradmoody ( 732860 ) on Thursday March 22, 2012 @11:21AM (#39440849)
    Do you see any merit in the "dense plasma focus" approach to commercial fusion power production, specifically the work of the Lawrenceville Plasma Physics group?
    • by Dr_Barnowl ( 709838 ) on Thursday March 22, 2012 @11:42AM (#39441213)

      I would mod up, but I have already commented.

      Their reactor design is certainly the most elegant, being the only device I've seen that proposes collecting the energy in a solid-state manner, and not just boiling a damn great kettle like everything else. It's also one of the smaller scale devices, the design reactor fitting in a shipping container and projected to cost on the order of a million dollars rather than being in the billions, producing on the order of 5 MW, making it a shoe-in for military funding to prime the development pump (the military would go ape for something the size of a shipping container that can produce 5 MW without having to ship in diesel fuel).

      It doesn't require rare and expensive tritium fuel. If their project manages to prove over-unity it would also seem to have the fewest engineer hurdles to becoming a commercial product, the difficulties mostly surrounding the construction of really fast high power switches, and an X-photoelectric collector.

      Their operating budget is tiny compared to the likes of NIF and ITER as well ; it would be great to see even a few percent of these budgets distributed to alternative approaches.

  • by Baldrson ( 78598 ) * on Thursday March 22, 2012 @11:23AM (#39440887) Homepage Journal
    In 1992, with the assistance of fusion technologists such as Robert W. Bussard, I developed legislative language for a series of 12 milestones, each of which would be awarded a $(1992)100M prize for the achievement of objectives toward the attainment of practical fusion energy []. This legislation also provided a grace period during which scientists and technologists that had been working on the US fusion program would be provided full salaries, without obligation, during which time they could seek support for their ideas to achieve these milestones. This legislation presaged a number of other prizes including the X-Prize and BAFAR []/CATS prize [].

    In 1995, Robert W. Bussard submitted this legislation to all relevant Congressional committees, copying all US plasma physics laboratories.

    Needless to say, the legislation wasn't passed.

    Do you think the time is right?

  • by tp1024 ( 2409684 )

    I haven't really found a concise statement on this so far. Assuming the current state of the art in plasma dynamics, how do fusion reactors scale with respect to size and magnetic field strength? Both in terms of the Q value of D-T reactions and D-D reactions. So, what happens when you scale up the size or magnetic field strength by a factor of 2?

    (What Q values have been achieved with D-D fusion anyway? I've seen 0.7 for JET in a real-world D-T trial in 1997. What's typical fori D-D? How much effort does it

  • by MpVpRb ( 1423381 ) on Thursday March 22, 2012 @11:31AM (#39441033)

    Is the ITER project good science?

    Or, is it a politically motivated, pork laden boondoggle?

  • Researchers studying different types of reactors (Bussard polywells, tokamaks, LENR like the Rossi eCat, Farnsworth fusors, etc.) seem to spend an inordinate amount of time making negative public statements about each others' work.

    Are there any researchers outside your own field that have attacked your work? Do you see this as a problem? Is it an unavoidable consequence of trying to gain funding when fission is the favored technology? Does all non-fission research suffer when fusion researchers fight amo

  • NIF (Score:4, Interesting)

    by Grond ( 15515 ) on Thursday March 22, 2012 @11:33AM (#39441059) Homepage

    Is the NIF approach even plausibly capable of generating electricity in a useful way, or is it purely a research platform / smokescreen for nuclear weapons research?

  • I've always heard that fusion was very, very difficult without Helium3, which is in short supply Earth-wise, but more available on the moon.

    How is your process dealing with the Helium3 issue (if at all), and how did you overcome the difficulties involved?

    Ironically, if we still had a space program, we'd probably have had fusion since the mid-80's since we'd be mining all that Helium3....

    • Sorry to tell you, but the whole He-3 story is a bunch of crap.Neither is He-3 rare, as it is absolutely no problem to make Tritium out of Lithium - you just need to wait 11 years for half the tritium to turn into He-3.

      That said, D-He-3 fusion is as hard to achieve as D-D and certainly much harder than D-T fusion. Worse yet, in D-He3 fusion there is a parasitic D-D fusion process that is actually favoured (by nature) over D-He-3. The whole thing is just irrelevant and a huge strawman.

  • by Rei ( 128717 ) on Thursday March 22, 2012 @11:40AM (#39441183) Homepage

    and even ignoring all questions of whether they can generate net useful, saleable electricity... how likely do you feel that descendants of tokamaks like ITER are to produce economically viable electricity (including capital cost amortization), given their large scaling requirements, and on what sort of timeframe? What about inertial confinement alternatives based on the HiPER [] approach? As an ousider, it seems to me that the HiPER concept can be scaled down much more, and hence looks more attractive as a generation method.

  • Your Favorite Books? (Score:4, Interesting)

    by eldavojohn ( 898314 ) * <(eldavojohn) (at) (> on Thursday March 22, 2012 @11:40AM (#39441185) Journal
    So I'm not a physicist (software guy) but I've taken a few physics classes. At an early age I found a tattered copy of George Gamow's One Two Three . . . Infinity [] which, although incorrect in some parts (I guess that's why they revised it and that's why 'speculations' was in the title), was perfectly written for my then fifth grade mind. It set me on a path toward science and a few weeks ago I saw the same 1960s Viking Press edition and flipped through it noticing what was slightly off and remembering it. I've since grown to love other obvious books like Hawking, Penrose, Hofstadter, etc.

    So, quite simply, what are your favorite books for all minds young and old? Also, can you annotate which are written for the layman's entry into the given field and which are written to encompass the field for the researcher? I find that some books start off with the jargon so strong and the references and footnotes so thick that you start to have to reread every paragraph as they're clearly condensing entire historic papers into lengthy sentences. Any fiction books worthy of influencing your work and desires?
  • by Anonymous Coward on Thursday March 22, 2012 @11:40AM (#39441187)

    There are many potential routes to economic fusion. Assuming each of these concepts were funded at ITER levels, how would you rank the potential for economic fusion (cost competitive with nuclear) coming from each of the following concepts within the next 25-30 years:
    1/ Field Reversed Configuration - eg Helion Energy, Tri Alpha
    2/ Electrostatic Confinement - eg Polywell/EMC2
    3/ Magnetised Target Fusion - eg General Fusion
    4/ Laser Inertial Confinement - eg NIF, HiPER
    5/ Heavy Ion Inertial Confinement - eg Fusion Power Corporation
    6/ Tokamaks - eg ITER, DEMO
    7/ Stellarator - eg Wendelstein 7-X
    8/ Levitated Dipole - eg MIT LDX

  • I figure everyone that is actively working on this project has an overall understanding as to what needs to be done before their part of the project "kicks in." But what of Logistics? Consider that glory of glories, tomorrow, it works. Someone is going to eventually call up and ask the question, "Great work team! But where do I plug in?"

    I figure, right about now, that in the back of the room that holds the team meeting for this project, 3 or 4 Engineering Gieniuses are vapor locking.
  • Where are the answers posted?

    • there's usually a follow up post in a few days or a week or so with Answers to a number of questions. It's not a live chat.

  • Achieving break-even fusion seems like it has to be an eventually achievable goal. After all, stars show us that it's just a matter of scale in the end and it's been achieved non-sustainably with fusion bombs (some have argued that sustainable fusion power is achievable now by detonating fusion bombs in giant underground chambers). The question I have is, once we have sustainable fusion reactors, are they really viable as a general-use power source? The reason I wonder is because, unlike stars which run on

  • by onyxruby ( 118189 ) <<ten.tsacmoc> <ta> <yburxyno>> on Thursday March 22, 2012 @11:44AM (#39441257)

    How do you extract the heat once you are successful in fusion? Is there a safe zone where it is just right to run water to convert to steam? With fusion running so hot and containment being such an issue it makes me think that extracting the energy could also be a fair challenge.

  • by reovirus1 ( 722769 ) on Thursday March 22, 2012 @11:44AM (#39441269)
    If the president came to you and said, "We have a national emergency. We need this to become a viable form of energy as soon as possible. You have the entire resources of the nation available. I will use my executive powers to make it happen. Whatever resources, funding and people you need..." What kinds of things would you ask for? How long with the entire backing of a nation and the political will to make it happen would it take?
  • by mwk88 ( 633079 ) on Thursday March 22, 2012 @11:45AM (#39441275) Homepage
    Focus Fusion Society [] is posting research on their project to do aneutronic e.g. Proton Boron (pB11) fusion. The concept sounds great, and as an engineer several parts of their design such as direct extraction of electric power are elegant. Is this credible research or pie-in-the-sky? I have not seen much mention in mainstream fusion research.
  • Making fusion power with a massive laser and a tiny bit of deuterium, is what's holding them back, it's rediculous! How about speeding a matter stream of deuterium atoms around a toroid, in a vacuum using superconductive "pinch points" around the circumference? it would set up tiny shockwaves of very high temperature and pressure. As the system is refined the matter stream could become self propelling, sacrificing only a very small percentage of deuterium atoms per cycle. And the potential power generation could be accomplished not through heat, but by using the spinning matter stream as the armature (rotating center) of a generator/alternator.


  • Do you have an estimate for how much fusion will cost per kWh relative to today's technologies, like fission, coal, and natural gas?

    I'm interested in knowing whether fusion will bring down the cost of electricity. A pet idea of mine for some time has been that commercial fusion power could bring down the cost of desalination enough that access to fresh water will no longer be a problem for countries that can afford to build the infrastructure in the first place.

  • What is your opinion of General Fusion's ( approach to a fusion reactor design?
  • It takes a long time to build merely the infrastructure needed to house and support a fusion facility. For political reasons, the sooner fusion is on-tap after we know how to achieve it. It probably wouldn't be a bad thing if there was a massive construction job program right now, given the current slump.

    Do we know enough about the needs of a fusion facility to start work on these surrounding projects?

    • Of all the phases needed to build a nuclear plant, the one that takes the longest is the planning stage. Getting all the permits, overcoming protests, NIMBYs, bribing the right (or left) politicians and quelling the opposition. We should be starting the publicity campaign and "educating" people that fusion is their future right now. That way, they'll actually welcome the arrival of commercial fusion power (changing the name to something less politically loaded is always a good idea, too).

      That will knock at

  • At this time, it seems prudent to say that the only reaction likely to ever produce commercially useful energy will involve copious quantities of tritium. Would you please address the main points of tritium self-sufficiency raised by Swiss physicist Michael Dittmar?
    The issue is raised in part 4 of his study, page 20, The illusions of tritium self-suciency []

    More background: []

  • by jank1887 ( 815982 ) on Thursday March 22, 2012 @12:26PM (#39441807)

    Fusion is one of those technologies that is always '50 years away', even 50 years ago, maybe even 50 years from now. So, looking at what's actually happened recently:

    What do we actually know now that we didn't know 10-15 years ago that gives support to the notion that we're making progress? Or, what are the 'big' things we know now?

    Similarly, what are the things we still don't know that we could reasonably expect to find answers for in the next 10-15 years?

    I'm assuming it's not that we've figured it all out and it's just a matter of engineering a working prototype.

  • This may be a stupid question, but...

    The power that it takes to generate electricity from a nuclear plant, I assume, is fairly immense. Does the power that a nuclear plant generate put out more pwer than it takes to generate it? I know that, for the most part, it is steam pwer, right? The rods get hot and they boil water that, in turn, generates steam. some of these plants seem pretty massive and must take a lot of power to operate.


  • I am bothered by the fact that people know full well that many inventions come about from different things being combined together, yet as far as nuclear fusion research is concerned, the researchers are largely divided into camps, each of which thinks its own approach is the One True Way. There are the magnetic confinement people, the electrostatic confinement people, the inertial confinement laser-blast people, the inertial confinement electron-blast people, the inertial confinement sonic-blast people, an
  • by Marrow ( 195242 ) on Thursday March 22, 2012 @12:37PM (#39441969)

    The byproduct of fusion is Helium? Or is it some other atomic number they are shooting for now (boron?) Anyway, if the plan is to make this a drop-in replacement for coal and natural-gas burners, then how will you keep the unit up and running if its filling up with waste prodcuts. Does it have to be taken down intermitantly? Then what is the startup-time / power requirements / redundancy requirements of a fusion reactor that has to be restarted every 10 days.

  • Why are 3 US tokamaks necessary for the US to benefit from ITER? Do they have different specialties or something?

    The argument here seems to be that in order to benefit from ITER construction, the US needs to have a domestic program counterpart. However, why, in a technical sense, are all the current facilities necessary in addition to the new ITER facilities? I'm sure particle physicists would love to keep Fermilab up and running, but its a harder argument to keep the hardware (the expensive part) in p

  • by ansak ( 80421 ) on Thursday March 22, 2012 @12:58PM (#39442241) Homepage Journal
    ITER/Tokamak has been around for a long time with, to say the least, disappointing results in the long haul.

    At some point, practical planning would say that a portion of the money -- even a very small portion -- being spent on ITER projects should be redirected to make sure that the pre-occupation with ITER isn't starving other options that may turn out to be better ideas. It's often been the outliers that succeed even in technology areas where lots of attention and money have been spent on some "standard" solution.

    I'm not against pure science but in this situation I'm likely to appear so to some: it's annoying to me that ITER, the long term "solution of the future and always will be" is getting so much money that other options are being starved out. Am I completely out to lunch for some reason?
  • by cjonslashdot ( 904508 ) on Thursday March 22, 2012 @01:09PM (#39442385)

    Given that solar energy is so plentiful, and that it will likely be widely available in the time frame that fusion power will be available, would it make more sense to apply the expertise of scientists into using fusion for spacecraft propulsion, which is an application that absolutely requires concentrated and compact energy? It could be a game-changer for travel within our solar system.

    In addition, could the techniques used for fusion (both magnetic and inertial confinement) be applied to fission propulsion, for compressing fissile pellets to critical density? And would that be more within reach of current technology than the very high temperature and pressure needed for fusion? Why is no one researching that? It would literally open up the solar system for us.

  • by Crispy Critters ( 226798 ) on Thursday March 22, 2012 @01:42PM (#39442793)
    What is the best estimate of the operating size of tokomak power plant? How many do we need to convert the US away from coal & gas power plants while switching to electric cars? What is the answer if we look at 100-year projections for population, energy usage patterns, and density? Will a tokamak-based power grid be more or less useful in parts of the world with different needs, like Europe, Japan, India, or China?

In less than a century, computers will be making substantial progress on ... the overriding problem of war and peace. -- James Slagle