Talk:Fusion power

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Totally Inaccessible

This article is totally inaccessible to any person without a good understanding of physics. At least one section needs to address the fundamentals of fusion power in a way that can introduce a novice to more advanced information contained later in the article. —Preceding unsigned comment added by 205.211.168.17 (talk) 17:28, 29 January 2010 (UTC)

The other fusion power?

I was just re-reading the intro, and I was struct by what appears to be a missing definition. The article currently talks about the "technical term", which is basically "the amount of energy being produced by a fusion reaction". But when I think of the term "fusion power", I normally think of something very different, a non-technical term that means "the entire concept of using fusion reactions as a commercal source of power". I'm not sure the body of the article doesn't cover the two terms in enough depth already, but am I wrong in thinking there is a missing intro paragraph that clearly defines this other use of the term? Maury 04:14, 4 January 2007 (UTC)

Bussard Presentation at Google TechTalks

Hi, just watched this rather interesting talk (Google Video) by Bussard at Google. He presents a non-grid-based ECF system that his team has been developing for the last 12+ years under a DOD contract. I'm no expert, so I dont know how credible the claims are in the presentation. However, he makes what appear to be rather controvercial statements, (related perhaps to thread above concerning Tokamak) and his views don't seem to be addressed in this entry. (first 20 or so minutes are fusion background, then talks about his recent work) --JulieKilo 04:11, 8 January 2007 (UTC)

I'm not sure how controversial the statements are -- I'm watching it now, and everything he's presenting seems to be on the up and up as far as physics is concerned, though he does quite a bit of humorous tokamak/mirror machine bashing. However, I'm not sure what place this should have in a general encyclopedia. It's quite cutting edge research at the moment.

I would really like to see some expert comments on the talk, since this can be a revolutionary discovery, thanks 202.82.238.30 08:01, 11 October 2007 (UTC)

Unsolved tag

I suggest that this tag should be removed. It short circuits and minimizes the major effort that is underway ( ITER ) to answer this complex question. ClaudeSB 22:34, 24 January 2007 (UTC)

I'm not even sure what section it was on! The article is a hotbed of undiscussed changes.

If the tag was on anything to do with materials or radioactive waste, it probably should have stayed. See IFMIF, and note that there is no mention of where it will be built, if it is. There's been a lot of silence lately, possibly because people are reluctant to ask for money for IFMIF until they are quite certain that it won't be at the expense of ITER, which is an enormous financial commitment already. Even worse, if IFMIF were to be cancelled as too expensive, that might mean ITER would be cancelled too, as pointless without IFMIF. So there's every reason to tread gently.

But IFMIF is critical to building DEMO, of course. Every delay to IFMIF means DEMO is also further away. Andrewa 19:44, 16 July 2007 (UTC)

tritium

I included the link for tritium to the article since it is relevant. --209.244.30.237 20:24, 10 May 2007 (UTC)

Fuel Cycles

Should someone put the 3He-3He or the D-3He fuel cycles into this? Matholomew 08:06, 15 April 2006 (UTC)

Should the letters in the fuel cycle equations have links, or explanations to what they are? For Example, the p in the The D-D fuel cycle equation. Is it representing proton or protium? Duncan Hill 05:16, 17 June 2007 (UTC)

It is actually irrelevant as protium is an atom with one proton and no neutrons. It is thus apparent that it can stand for both proton and protium. 72.1.206.17 (talk) 13:20, 15 December 2008 (UTC)

Future plans and predictions of development

I can't find future plans for fusion power and predictions of it's usage development in entire article. Can somebody add plans (which are referenced) and add some notable predictions of how long will it take to reach some level in development of fusion power, possible years or similar. I cant't find any future years in the article. It would be good if article gives reader a little sense of speed of research on this fields. Thanks. --83.131.77.136 10:36, 14 July 2007 (UTC)

The recent addition saying fusion is "not practical" seems to be an opinion based purely on an editorial in New Scientist and IMHO should be undone or relegated to a simple POV reference. Editorials often present a strongly biased viewpoint to stimulate discussion, so should not be presented as evidence.

The main issue raised, containment, might be solved soon - for example by measuring deviations and applying compensating magnetic fields. Relaxed stability algorithms as applied to unstable aircraft like the Grumman X-29 could be relevant here.

I can't find it this minute, but a few years back the electrical generation industry group published a report stating quite clearly that even if fusion were made to work in the short term they would be unlikely to deploy it commercially. The size of the reactors has to be quite large to make them economically viable, but large reactors have supply and demand effects on the electricity market that make them difficult to pay for. I'll see if I can dig it up. Maury 19:12, 26 July 2007 (UTC)

I wanted to comment on this paragraph:

The recent addition saying fusion is "not practical" seems to be an opinion based purely on an editorial in New Scientist and IMHO should be undone or relegated to a simple POV reference. Editorials often present a strongly biased viewpoint to stimulate discussion, so should not be presented as evidence.

Please see WP:NPOV, which is about representing fairly and without bias all significant views that have been published by reliable sources. This is non-negotiable and expected on all articles, and of all article editors. New Scientist is certainly a reliable source, and so should be included as part of NPOV. There can be no question of excluding this reference. -- Johnfos 21:14, 26 July 2007 (UTC)

New Scientist? Oh yes there can! Its the "reliable sources" bit that's at issue. Maury 12:36, 27 July 2007 (UTC)

How so? The only parts of New Scientist I've considered as not being reliable are the advertisements. (anonymous user who isn't registered here but has an interest in fusion, 12:26pm, Tuesday 31st July 2007)

New Scientist often publishes articles that have no scientific merit and are printed primarily because they are controversial. It is a news magazine, remember. For instance there was the NASA programmer who was going around telling everyone that aerospace engineers were all wrong and that lift is actually really simple. This topic comes up over and over, I believe the editors of NS are aware of this and find it somewhat amusing. There's ample examples of the debates that result of using NS as a source here on the wiki. Maury 12:33, 31 July 2007 (UTC)

I agree, an editorial is largely based on opinion, thus making it POV. Also, even reputable and reliable sources will often vary in opinions. I guarantee that those men working on ITER believe fusion to be practical, and they are equally knowledgeable compared to "New Scientist". We need to argue both sides to stay neutral. Intense adolescent (talk) 13:53, 15 December 2008 (UTC)

Updated diagram to SVG

I've created

to replace

. Please someone check it and replace the old one with the new one IF it is correct. Otherwise, notify me on my talk page. Thanks. wykis 17:10, 15 October 2007 (UTC)

Isn't the DT Gain scale odd in that it lacks 1 (10^0)? --81.216.218.158 (talk) 23:56, 7 January 2011 (UTC)

Accident potential, needs sources

I rewrote a bit of the accident potential section. It really isn't the fuel inventory that is the problem in fission reactors, but rather the physics of the reaction, which can ( in some designs ) cause it to run out of control, or lead to a meltdown. In particular, fission gives rise to very neutron-rich fission products that continue to produce heat through beta-decay for a long time after the reactor has been shut down ( and this was part of the problem in the three mile island accident ). A Chernobyl style runaway reaction really is an impossibility in most modern designs as they are designed with strong negative temperature coefficients, thou I guess you get that behaviour "for free" in a fusion reactor. I tried to clarify this. In either case the section is horribly short on sources, thou many should be easy to find in other articles on nuclear safety. I don't feel very confident with the reference system, so I won't try to do it myself. 85.230.195.192 03:06, 23 October 2007 (UTC)

Perhaps look into http://www.iter.org/safety, this is the official safety page of the ITER project. I'm also new-ish to references, anddon't know how best to break this down. LightRobb (talk) 13:27, 19 April 2012 (UTC)

Question on sustainability

I see no problem with this passage:

"Fusion power has been touted as a "renewable" energy source. This is incorrect - any scaled-up use of fusion power would consume more deuterium than the Earth would receive from cosmic sources. Heavy water is the only sizable natural source of deuterium on Earth. Over time, a stable fusion economy would slowly but steadily deplete the concentration of heavy water in the planet's water bodies from the natural ratio of one deuterium atom for approximately every 6400 protium atoms (i.e. one heavy water molecule per 3200 water molecules) as depleted stocks of water return to the planet's water bodies. Unless total energy consumption on the planet was increased by several orders of magnitude, then this would not pose a serious problem for millennia as the total amount of deuterium in the planet's oceans is estimated to contain at least fifty million times the equivalent energy content in the planet's remaining fossil fuel supplies. If the entire planet scaled up its per-capita energy consumption to the level of Qatar (which consumes almost three times the energy consumed per capita compared to the United States) using fusion power, then even with a world population exceeding ten billion the planet's deuterium reserves would still last for thousands of years at least. However, this does not take into account the tendency of the human population to grow exponentially. Nonetheless, over many centuries the energy costs related to extracting deuterium would steadily increase as the concentration of deuterium in natural sources steadily decreased (assuming no improvements were made to the extraction technology and methods). In the hypothetical event that humanity sustains itself for several millennia primarily on fusion power, then deuterium depletion could potentially create major challenges for our distant descendants."

Why shouldn't we include this? Yes, the fusion fuels on Earth won't last infinitely, but neither will the hydrogen in the stars.

Anyone care to discuss the worthiness of this section?

AWeishaupt (talk) 00:38, 18 December 2007 (UTC)

The above as presented is just straight WP:OR, it has no sources, it is just an essay, and is fatally flawed in two respects, one it talks about "would still last for thousands of years", a blink of an eye compared to the billion years we will be here, and it states "the tendency of the human population to grow exponentially", yet fails to observe the finite area of the surface of the earth. We are already close to what we expect the final population of the planet (within 50% or so), however it doesn't include populations expanding into outer space, in earth orbit, within the solar system, and beyond the solar system. The only way you can continue to project exponential population growth is to expand beyond the solar system at some point, and once you have left the earth you continually open up new sources for energy. At this point I think the article should discuss the hypothetical possibility of obtaining any energy at all from nuclear fusion, not the hypothetical possibility of sustainability of nuclear fusion. A short indication of the potential supply of availability of fuel is all that is needed. The way technology changes so rapidly it is difficult to speculate beyond about 300 years. Or even 30 years. 199.125.109.134 (talk) 04:01, 18 December 2007 (UTC)

Isn't there a section in this article that says that fusion power could last for billions of years, not just thousands? —Preceding unsigned comment added by 65.34.82.144 (talk) 18:56, 29 August 2008 (UTC)

I know this is an old discussion, but it seems to still be relevant, so I would like to note that fusion power might be possible using regular hydrogen, not deuterium. However, it is a lot easier with deuterium, which is why all the research uses it. Second, Deuterium can be produced. I don't know the specifics, but you need a neutron generator, liquid hydrogen, and some additional non-expended components to conduct the neutrons into the liquid hydrogen. Anyways, deuterium CAN be generated, it's just a lot cheaper and more efficient to gather it. --Robert Wm "Ruedii" (talk) 20:44, 18 May 2012 (UTC)

It could in principle be produced, but only in miniscule quantities compared to those existing naturally (since there are no mass-scale "neutron generators"), and possibly losing more energy than the deuterium can later produce itself, so that makes no sense at all. --Roentgenium111 (talk) 20:24, 26 July 2012 (UTC)

Waste (helium and oxygen)

How much waste would a large scale implementation of fission-technology produce? At what point would it make an impact on the atmospheric conditions? MX44 (talk) 13:16, 12 February 2009 (UTC)

A fusion reaction produces about 10^7 times more energy per atom than a chemical reaction. If it takes hundreds of years to produce enough CO2 to influence the climate by burning coal, then it would take billions of years to produce the same quantity of helium. Of course, helium isn't a green house gas, and it is lost to space from the atmosphere on a scale of millions(?) of years. Not a problem. --Art Carlson (talk) 15:23, 12 February 2009 (UTC)

Good Article

Any objections to listing this article as a WP:Good article candidate? References a sparse, especially in the beginning, so that's something that will need to be addressed. - RoyBoy ⁸⁰⁰ 00:37, 20 February 2008 (UTC)

How will the world look like when the first fusion plant is ready

I think we will have so much photovoltaic, that it's not possible to sell electric power in the summer time. But the high investition for a fusion power plant is uneconomic, when the plant can sell only in winter electric power. Here my study. --Pege.founder (talk) 15:16, 14 April 2008 (UTC)

I would like to hedge the bets for my children future on this planet between as many potential energy sources and technologies as possible. Even if we had a feasible technology today we should still invest into alternatives. Roeschter (talk) 05:25, 3 January 2009 (UTC)

Wrongly interpreted source.

I removed the phrase about "long half-life waste" being generated in a fusion reactor as it states as its source this article from BBC News site. What I found the article states and would match the assertion is: "It has been calculated that after 100 years of post-operation radioactive decay, Iter will be left with about 6,000 tonnes of waste. When packaged, this would be equivalent to a cube with about 10m edges.". As I see it the cube of waste mentioned is non-radiactive in the common sense. What could be misleading is that in fact these materials would be "very long half-life waste" as all so-called stable isotopes are. Please tell me if I've been too hasty with this, I'm a newbie contributor. Preymond (talk) 18:25, 6 July 2008 (UTC)

make the oceans lighter?

seems a rather odd comment i know... but if we started to extract all the "heavy water" from the oceans, wouldn't they get lighter? i am sure that could upset some of the marine ecosystem?--UltraMagnus (talk) 17:15, 31 July 2008 (UTC)

The biological effects of deuterium are well researched, just take a look at the article. Removing it completely has no effect. Increasing concentration to >30% does have an effect. Roeschter (talk) 05:26, 3 January 2009 (UTC)

Since deuterium is naturally present at only about 1 part in 6400 in water (see the Deuterium article), there would be no effect even if all the deuterium was consumed. Gierszep (talk) 02:27, 15 April 2011 (UTC)

There probably would be the effect that the oceans would get somewhat smaller (on the order of a sea level decrease of ~0.5 m) if the heavy water is removed without replacement (e.g. the D-T reaction does not produce any hydrogen-1), since no large amounts of elementary hydrogen is available on Earth to replace the missing (heavy) water molecules. --Roentgenium111 (talk) 19:32, 26 July 2012 (UTC)

Image copyright problem with Image:JointEuropeanTorus internal.jpg

The image Image:JointEuropeanTorus internal.jpg is used in this article under a claim of fair use, but it does not have an adequate explanation for why it meets the requirements for such images when used here. In particular, for each page the image is used on, it must have an explanation linking to that page which explains why it needs to be used on that page. Please check

• That there is a non-free use rationale on the image's description page for the use in this article.
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This is an automated notice by FairuseBot. For assistance on the image use policy, see Wikipedia:Media copyright questions. --02:00, 17 September 2008 (UTC)

Figure seems to have been removed. Problem solved. Gierszep (talk) 02:27, 15 April 2011 (UTC)

History of research

I thought the sentence "In a hydrogen bomb, the energy released by a fission weapon is used to compress and heat fusion fuel, beginning a fusion reaction which can release a very large amount of energy." is misleading since there is no mention in the section that most of the energy released in a fusion bomb comes from fission rather than fusion. Fusion is utilized because it produces large amounts of neutrons, which promote a much more complete fission reaction.

Isaac 150.243.39.17 (talk) 04:54, 5 October 2008 (UTC)

I agree the section states that hydrogen bombs release most of the energy is from fusion, when the pages on nuclear weapons state that the purpose of the fusion is only to release neutrons to increase the rate of fission, were most of the energy comes from. I’m going to go ahead and change it. --Disagreeableneutrino (talk) 07:41, 21 October 2009 (UTC)

Recycling of heat through endothermic fusion of Iron

When Iron fuses with itself, the result is an endothermic reaction. Normally endothermicity absorbs heat and makes it unavailable. However, due to the nature of the strong force - whatever occurs inside a particle having it also occurs in every other particle having it. The absorbed heat in a nucleus of Iron does not have to be shared through normal means in order for its expression. The inherent magnetism of Iron makes heat highly recyclable, and through that releases energy. Invest in Iron-based catalysts for the Oil industries, yes. 74.195.28.79 (talk) 21:28, 25 October 2008 (UTC)

Theoretical power plant design: Materials

This section is taken directly from the IFMIF article on Wikipedia. Considering that IFMIF hasn't been built yet, perhaps it would be wise not to solely include the potential materials for this specific experiment. I'd suggest including information about previously used materials in fusion experiments, how effective or ineffective they were, whether or not their effectiveness was adequately tested base, on realistic situations in a commercial fusion reactor, and the hypothetical reason that they are/were effective or ineffective. Does anyone else agree? Intense adolescent (talk) 13:42, 15 December 2008 (UTC)

volatility and biological activity of waste products

This sentence was recently removed:

Furthermore, there are fewer unique species, and they tend to be non-volatile and biologically less active.{{Fact|date=April 2008}}

with this edit summary:

Removing irrelevent sentence. Species in nuclear fission reactions???

I regret that I don't have a source for this, but the sentence does express important differences in the wastes from fusion and fission. Fission products consist of essentially every element from hydrogen to uranium, and many different isotopes of those elements. So you get a lot of nasties, like iodine and cesium and strontium that are both volatile and biologically active. Leaving tritium aside, radioactive waste from fusion is mostly activation products from impurities in the structural material. There are only a handful of these impurity elements, and they tend to be both relatively inactive from a biological standpoint, non-volatile, and locked into the matrix of the structural material anyway. I think the info should be kept in some form. --Art Carlson (talk) 16:28, 18 February 2009 (UTC)

Fusion bomb vs Fusion power

In response to this edit summary, "rm digression - this article is about fusion power, not about the political arrangements of the NIF," you are absolutely correct. This article is about Fusion power. And to mention the information in the disputed section is incredibly misleading. It was developed to aid the US nuclear arsenal. This is mentioned several times in the source. The article says the super laser can produce more power than was put into the system. Hooray, so can nuclear bombs. At this point, literally no steps towards fusion power have been produced by this system. So whether or not it deserves a mention in this article is very much debatable. If it needs to be mentioned, we need to explain that this is part of a weapons system. As the section stands now, it seems to imply that we've overcome the largest technical obstacle and that fusion power is right around the corner. AzureFury (talk | contribs) 11:13, 11 September 2009 (UTC)

The whole paragraph is strange! I agree that it talks things up quite a lot - the NIF has only just been completed, it hasn't yet produced results. But the idea of using laser confinement for fusion power is entirely reasonable. I'm not sure it's realistic to describe the NIF as a weapons system though - it's a research facility which does research both for civilian (fusion power) and military (nuclear weapons) purposes. Ultimately, NIF is funded by the US Department of Energy (which also has a split focus between civilian power and nuclear weapons). In any case, I think this is all a digression from the topic. Djr32 (talk) 21:11, 11 September 2009 (UTC)

NIF is the first inertial-confinement fusion experiment to stand a chance of reaching ignition (self-sustaining burning), after the Nova laser failed to do this. So, I'd argue that it's relevant to mention it (just as it's relevant to mention ITER in the context of magnetic-confinement fusion). --Christopher Thomas (talk) 21:44, 11 September 2009 (UTC)

This is from the article: "Although it took less than ten years to go from military applications to civilian fission energy production,[3] it has been very different in the fusion energy field; more than fifty years have already passed[4] without any commercial fusion energy production plant coming into operation." This contradicts the implication made in the disputed section that being able to produce weapons and produce usable energy are near equivalent. AzureFury (talk | contribs) 19:43, 12 September 2009 (UTC)

You seem to be making very strange assumptions about what the National Ignition Facility is and does. It is a large laser system that zaps a small pellet of hydrogen isotopes, trying to get significant amounts of fusion to occur. The weapons-related application of this is to allow better study of hydrogen plasma at fusion conditions (which is important for designing better fusion bombs). This is enough for it to get military funding, as the US military likes being able to design improved weapons without having to conduct nuclear tests. NIF itself produces no weapons of any kind (it's a prototype inertial confinement fusion reactor).

There is no implication, in the disputed section or elsewhere, that producing fusion weapons and producing fusion power are equivalent. That is, in fact, the core of the dispute (you seem to feel that NIF is a weapons plant of some kind). --Christopher Thomas (talk) 20:33, 12 September 2009 (UTC)

The comments in the source about the applications of this technology state that it will be used to aid the US nuclear arsenal. So I guess that isn't an implication. It's an explicit statement. The source also labels the NIF as a "weapons lab." Don't know where I got that crazy idea. I admit I'm not an expert on the subject matter. All I have to go on is the article and the source. This is what the source says, "a US weapons lab has new technology that will be used to improve fusion bombs." This is what the article says, "a scientific lab has made a fusion reaction that produces more energy than was put in." These are not the same statements. AzureFury (talk | contribs) 20:53, 12 September 2009 (UTC)

I direct you to the large number of references and sources cited at National Ignition Facility#References. You may also wish to read the National Ignition Facility article itself. --Christopher Thomas (talk) 00:22, 13 September 2009 (UTC)

I see nothing contradicting the statement made in the source that it is a weapons lab that created this technology. I'm re-adding that. AzureFury (talk | contribs) 16:15, 13 September 2009 (UTC)

Neither of the sentences you put in quotes above are actually direct quotes - the second one is not even an accurate paraphrasing (the news article relates to the end of construction of the NIF, they haven't yet demonstrated ignition). But most of what you're asking for is already covered in the section on Laser inertial devices above: "Most research in this field turned to weapons research, always a second line of research, as the implosion concept is somewhat similar to hydrogen bomb operation. Work on very large versions continued as a result, with the very large National Ignition Facility in the US..." I propose replacing the whole discussion in the "Current status" section with a simple statement along the lines of "construction of the NIF has been completed, and it is hoped to demonstrate ignition in 2010". Djr32 (talk) 17:50, 13 September 2009 (UTC)

That would force interested people to research the NIF in more detail, which I think would be a fair compromise. AzureFury (talk | contribs) 18:45, 13 September 2009 (UTC)

I have re-worked the paragraph in question, only mentioning that LLNL is primarily a weapons lab. I agree that the weapons connection is of peripheral relevance in the context of an article on fusion power. The temperatures needed for controlled fusion do not occur in planetary cores, and such cores are irrelevant to the subject of this article. It is also silly to talk about the laser having "the ability to strike a hydrogen atom", so I dropped that; only hydrogen plasmas are relevant here (hydrogen atoms cannot even exist as atoms at the temperatures required for fusion). Wwheaton (talk) 20:09, 13 September 2009 (UTC)

I endorse your rewritten version ([1]). --Christopher Thomas (talk) 02:05, 14 September 2009 (UTC)

Tritium decay energy

Regarding this change, does tritium's low decay energy actually make it less harmful? It certainly reduces the penetration distance, but since it's acting from within the body either way, that shouldn't be an issue. I can see an argument for it scattering fewer electrons and ions and producing fewer secondary showers as it passes, so it could very well cause less damage, but higher-energy beta radiation has a lower interaction cross-section, so should produce fewer events per unit distance travelled. I'm leaving it in, but I'd feel more comfortable if a reference for this change could be dug up. --Christopher Thomas (talk) 06:44, 21 September 2009 (UTC)

Good question. I think it depends on whether you are interested in the damage per decay (less) or the damage per energy (more). I have often been guilty of mentioning the low energy as a plus, but it is in fact a poor measure of biological damge potential. The short half-life could be viewed in a similar way. The problem is not around as long, but the damage done by each atom released is higher. --Art Carlson (talk) 07:54, 21 September 2009 (UTC)

Continuing this train of reasoning, it looks like it depends on whether we're reporting release of radioactive materials in terms of decays per second per unit mass/volume of contaminated material, or in terms of power per unit mass/volume of contaminated material. Tritium would have a much lower dose per decay but not per unit energy. I seem to recall that waste activity levels are reported one way (Becquerels) and dosage of people exposed another (Grays). Presenting this accurately in the text will be a challenge. --Christopher Thomas (talk) 08:32, 21 September 2009 (UTC)

More info on Polywell Fusion

This recent blog post was an incredibly enlightening source of links to resources on Polywell Fusion. [2] I don't see it in the article external links but will place it here for other editors to consider if it is article linkworthy. N2e (talk) 14:32, 5 October 2009 (UTC)

I'm not sure if there actually a policy against it, but I am uncomfortable with linking to a collection of links. If the target links are really such high quality, then we should sift out the best of those and link directly. --Art Carlson (talk) 15:09, 5 October 2009 (UTC)

Levitating Dipole Experiment

Here is an interesting news article about a "Levitating Dipole Experiment" that might be an interesting addition to this article. I'm not sure if Live Science would be regarded as a reliable source. Would anyone object to me adding a brief mention of this development? One runs the risk of yet another "fusion is just around the corner" pep rally, I know. CosineKitty (talk) 19:24, 28 January 2010 (UTC)

help with old reference

many years ago, Science magazine, published by the AAAS, and widely regarded as one of the most prestigous science magazines in the world, published an editorial or comment by an engineer on fundamental problems with fusion power, which addressed real practical engineering issues like heat transfer. does anyone have a citation, or, better a PDF ?Cinnamon colbert (talk) 17:23, 29 January 2010 (UTC) http://www.sciencemag.org/cgi/pdf_extract/199/4336/1403 —Preceding unsigned comment added by Cinnamon colbert (talk • contribs) 17:26, 29 January 2010 (UTC)

Any AAAS member can download a pdf out of the Science archives, as part of their AAAS membership. I am a member, and have just looked into their archive, where I find: "Engineering Limitations of Fusion Power Plants", by W. E. Parkins, Science, Vol 199, pp 1403-1408. 31 March 1978. The author was the Director of Research and Technology at Atomics International in San Diego, CA. The two problems highlighted were (1) non-competitive capital costs of proposed plant designs, and (2) the operational limitations from the effects of radiation on the first wall of the containment vessel for D-T reactors or others producing high-energy neutrons. Of course after 33 years, I presume some progress has been made on these issues, but I cannot say to what extent Parkins's concerns have been addressed. The article is the second of two in that issue of the journal; although I have not downloaded the first, the concluding paragraph ends, "... nevertheless, the strategy outlined here suggests that tokamak fusion power could be demonstrated with reasonable expenditures of money." Wwheaton (talk) 02:46, 5 March 2011 (UTC)

This Article lacks Citations

Nuff said. 173.75.234.3 (talk) 23:17, 22 July 2010 (UTC)

Confinement methods mixup

Magnetic confinement - ok

Pinch devices - there should be a clear distinction between pinching the fusing plasma itself or pinching plasma in order to hit the fusion target. The latter (as in Z-machine) is a subtype of inertial confinement (fast moving mass hits the target).

Inertial confinement - should be Inertial electrostatic confinement or maybe just electrostatic confinement. It is very different from other inertial confinement methods (laser, ion/electron beam, z-pinch, etc) —Preceding unsigned comment added by 89.77.86.97 (talk) 19:16, 15 August 2010 (UTC)

Economics

The economics section is misleading in that it compares budget fusion research vs other research for one EU agency. The overall effect is that it seems like fusion is getting disproportionate funding when research for other fuel sources are funded through other agencies. —Preceding unsigned comment added by 128.195.141.204 (talk) 08:52, 5 January 2011 (UTC)

Error in figure?

It looks to me as if there is probably an error in the "IFE and MFE parameter space.svg" figure here, as the DT gain contours look wrong. There are five contours (labeled 1e-5 to 0.1) with a claimed spacing of 10× to the lower left, and then three (labeled 10 to 1000) at the upper right, also spaced 10×, but the "DT gain"=1 contour is missing. If it were present between 0.1 and 10, the spacing for just that one contour would be about half all the others before and after, so I think the labeling must be incorrect. Can one of our experts check this? Thanks. Wwheaton (talk) 15:22, 13 March 2011 (UTC)

Balance of article

I'm a bit concerned the article doesn't fully balance tokamak and laser designs with due weight. Can someone take a look? FT2 ^{(Talk | email)} 15:01, 30 March 2011 (UTC)

Solved it, I think - review? FT2 ^{(Talk | email)} 15:53, 30 March 2011 (UTC)

Advantages

I have editted this section as follows:

- Used more precise in discussion of renewables and sustainables. Fusion is not renewable, but is effectively indefinite energy source. I also fixed the link to the paper documenting this long life.

- I moved up the discussion about no greenhouse gases and dependable power, as I think these are stronger than the next couple of arguments.

- I simplified the discussion on fusion and economies of scale. Fusion power stations would be large and require sites with cooling water, at least with current technologies. This will also limit the number of optimal fusion power sites. I can see arguments both for and against fusion economies of scale relative to other options. I have left the point, but reduced the claim as I am not entirely convinced and it is not presently defended by references.

- The discussion on desalination is also challengable. It is hard to see that the probable lack of fresh water this century in much of the world could be solved by a very expensive energy source. And if indeed desalination was feasible with expensive energy, it is not obvious why that would be an advantage for fusion, and not for a variety of other energy sources. Also, the concept that the process used to extract the fusion fuel would itself provide useful amounts of water seems to me to be irrelevant. The energy released from the fusion fuel would provide much more desalination power than the small amount of water possibly associated with fuel extraction. Again I have left the main point for now, but reduced the amount of discussion.

- I think there are some other advantages that might be raised here, but I have not yet done so. E.g. large (industrial) amounts of power, possible high conversion efficiencies in advanced fusion concepts, and ultimately possible role is space travel.

Gierszep (talk) 03:51, 15 April 2011 (UTC)

Your edits show a more neutral point of view, which is good. Concerning the advanatages that are not pointed out yet, what role may fusing power bring for space travel? A better and contained energy source? Some current unmanned missions use fission nuclear power for on-board systems. I even wonder if SMART-1 didn't use such a power source for its ion thrusters, more specifically its Hall effect thruster, Snecma's PPS-1350.

I have changed the "citation needed" flag to a "fact" flag for the following passage:

Another aspect of fusion energy is that the cost of production does not suffer from diseconomies of scale. The cost of water and wind energy, for example, goes up as the optimal locations are developed first, while further generators must be sited in less ideal conditions. With fusion energy, the production cost will not increase much, even if large numbers of plants are built.

In fact, the point which is made here is not that some sites may or may not have as much water needed to cool the reactor (and some reactors don't even need water if I'm not mistaken) but more that wind turbines impact the actual wind, rendering the installation of wind turbines near other problematic, and idem for water energy plants which require a minimum of current to operate efficiently. In other words, you can build as many fusion plants as you want, the price of these plants shouldn't increase with regards to its location because the location just doesn't matter.

Xionbox^₪ 06:29, 15 April 2011 (UTC)

There's more to economies of scale than just real estate and resource quality. You'll see a theoretical increase in price(especially early on) due to skilled labor shortages, according to the basic economic theories. Nuclear engineers and technicians aren't cheap, and there are only so many. If we're willing to accept original research as a basis for statements in the article, you'll be faced with the real problem that the inverse can be claimed just as easily. Please keep the fact tag, as there's a reason WP:OR exists. Truth or falsehood has little to do with it. I also removed some of your change because of the tone and redundancy against the previous sentence. i kan reed (talk) 13:54, 15 April 2011 (UTC)

JT60, Q>1

The article lacks mention of the japanese JT60 tokamak, which operation lead to some outstanding achievements. As given on the JT60 project homepage http://www-jt60.naka.jaea.go.jp/english/jt60/project/html/history.html this reactor has already achieved *more* fusion output power than consumed power (Q>1) since 1996. In the paragraph "Current Status" the article just states "Several fusion D-T burning tokamak test devices have been built (TFTR, JET), but these were not built to produce more thermal energy than electrical energy consumed." It should be corrected, since this phrase sort of suggests, that Q>1 was never reached. In fact Q>1 *was* reached, but due to the fact that the machines were not built for such high power removal from their structures (as the quoted sentence from the article nearly correctly states), it was only sustained for short periods of time in order not to damage the machines.

Current Status updates please

Could use updates including Focus Fusion and Polywell with respective sources (Focus Fusion webpage and recovery.gov - the latter is just a step away from a peer reviewed journal, as the funding would dry up if the project goals are not demonstrated). — Preceding unsigned comment added by 74.232.3.28 (talk) 17:51, 22 August 2011 (UTC)

Scientists claim that power from nuclear fusion is just 30 years away. That's kind of a running joke. (They claimed this back about in 1960, and were still claiming the same in 1990. I don't think they're so optimistic these days.)--71.38.171.80 (talk) 16:39, 28 October 2011 (UTC)

File:Wires array.jpg Nominated for speedy Deletion

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laser induced fusion energy

This press release from Sept 2009, starts with: "Attention is given to a rather shocking new discovery: NUCLEAR ENERGY WITHOUT RADIOACTIVITY".

Is this a topic that should be added to this article ? --POVbrigand (talk) 08:53, 27 October 2011 (UTC)

No. Or rather, the topic is already covered. Look at the section Fusion_power#p-11B_fuel_cycle, which links to Aneutronic_fusion#Residual_radiation_from_a_p.E2.80.9311B_reactor. Furthermore, a press release is not generally a reliable source, there is no sign that anyone else is paying attention to this, and the accuracy of the content is questionable. --Art Carlson (talk) 09:42, 29 October 2011 (UTC)

Thanks for the clarification. --POVbrigand (talk) 16:00, 29 October 2011 (UTC)

Neutron reflection and absorbtion; waste reduction

Neutrons reflected into the plasma can be used up breeding Tritium from Lithium instead of activating the PFCs, the coolant or other materials behind. Does anyone know sources for materials and designs which achieve that kind of reflection, and about their efficiency?

1. Neutrons are hard to reflect.
2. You don't want lithium in your plasma because it will radiate away the energy.
3. The mean free path of neutrons in a fusion plasma must be millions of kilometers.

--Art Carlson (talk) 07:54, 14 November 2011 (UTC)

Also, can radioactive isotopes be efficiently separated from non-radioactive isotopes in the aforementioned materials, limiting the amount of waste produced? Can these radioactive materials be in any way reused in the same facility, so that the don't need to leave the grounds and be deposited as waste.

Doomguy (talk) 17:21, 13 November 2011 (UTC)

Recent edits

A lot of sourced material and associated citations seem to have been dropped from the article recently. On 24 December 2011 the article had 45 references (see [3]), but now the article has only 37 references ([4]).

A particular concern is that several important references, which helped to bring some balance to the article, are now missing (See Scientific American and New Scientist).

What is going on? Johnfos (talk) 20:43, 1 January 2012 (UTC)

Have reverted edits by FT2, to restore sourced material and missing citations. Johnfos (talk) 04:24, 3 January 2012 (UTC)

LENR, etc?

I posted the same question in the list of fusion experiments page, but...

Is there any particular reason why the multitude of LENR experiments (MIT, NASA, Osaka University, DARPA, Navy SPAWAR, (Navy) NRL, Andrea Rossi, etc) aren't even given mention here as an experiment?

Barwick (talk) 13:51, 29 May 2012 (UTC)

Bueller? Anybody? If you don't have any opposition, I'll work on putting together a short writeup about LENR experiments. Barwick (talk) 15:05, 6 June 2012 (UTC)

Fusion as economic energy source

I've been reading recently about entropy and remembered reading once about how inefficient energy wise the fusion process is in the sun. Maybe I'm been a complete porridge head here as I'm not a scientist, but how is fusion as an net energy source not a violation of the second law thermodynamics. I understand with fission fuel the work was put in during the supernova implosion but I'm confused with regards to fusion fuel.

W66w66 (talk) 19:49, 12 September 2012 (UTC)

It's the Big Bang. The universe started with essentially infinite temperature, i.e., zero entropy. For the most part, it remained in thermal equilibrium while it was expanding, including a soup of protons and neutrons. But that soup cooled down a bit too fast for all those particles to glob together into helium. Only 25% of them made it. The rest are left over as protons that would like to form helium, if someone would give them a second chance. Art Carlson (talk) 08:01, 13 September 2012 (UTC)

The energy isn't coming from nowhere, it's coming from the matter being fused; note that there is an actual mass difference between the products pre-fusion and post. The difference in mass is what we get as energy. IRWolfie- (talk) 15:28, 14 September 2012 (UTC)

Kir Komrik links

These links have been added under "External links" four times now, once by Special:Contributions/75.61.203.110, twice by Special:Contributions/75.247.196.89, and once by Special:Contributions/75.208.86.211:

• Twenty-One Castle Mike Twenty-One Castle Mike by Kir Komrik under commission of [name withheld] Marine, LLC.
• Twenty-One Castle Mike Diagrams Twenty-One Castle Mike diagrams by Kir Komrik under commission of [name withheld] Marine, LLC.

These links are a violation of a number of the content guidelines specified under WP:LINKSTOAVOID, in particular

1. Any site that does not provide a unique resource beyond what the article would contain if it became a featured article.

2. Any site that misleads the reader by use of factually inaccurate material or unverifiable research, except to a limited extent in articles about the viewpoints that the site is presenting.

and especially

11: Links to blogs, personal web pages and most fansites, except those written by a recognized authority. (This exception for blogs, etc., controlled by recognized authorities is meant to be very limited; as a minimum standard, recognized authorities always meet Wikipedia's notability criteria for people.)

The editor adding these links (presumably), left me this message at User talk:75.208.86.211:

Art -

I've read the policies here and there is no policy violation for these links, nor do I see why you denominated it a "crank" website. You are vandalizing legitimate links, please knock it off.

I have reverted this edit twice, and will do so again, but it would be better if other editors were also involved. Art Carlson (talk) 22:50, 4 November 2012 (UTC)

I just removed these links again. I should make it clear that there are a number of reasons they should not be included, but the most straightforward one is point 11 of WP:LINKSTOAVOID: They link to personal web pages of a person who is neither recognized as an authority nor otherwise notable. Art Carlson (talk) 16:30, 5 November 2012 (UTC)

Not sure if I'm responding in the correct place and space, but in any case, I will grant you that the policy application is necessarily subjective. However, there are references within the article to peer reviewed, mainstream research regarding traditional tokamak fusion. So, that policy is not violated. As for factual inaccuracy, if you could point out some mistatement of facts it might advance the conversation since I can't find any, nor can hundreds of other readers. The part about blogs is surprising because I see links from wikipedia "all the time" to blogs. So, it isn't clear to me how that is being applied. But let me say this, if an article happens to be served up in the domain space of a blog, should that really disqualify it by itself? Finally, anyone who deletes links to this article without realizing what they are deleting is harming the advancement of research in fusion power. Not all research is published in traditional peer-reviewed material when corporate America is obssessed with trade secrets (and there is a reason why this was published in this manner). Furthermore, I cannot provide all of the information I would like to for the reader because I am under obligation of a non-disclosure agreement. I really think someone competent in the field of magnetic tokamak fusion should read the article and vet it as a peer review might do, because I believe you are making a mistake by deleting these links. I understand that you have a valid interest in maintaining site credibility but if you take this too far you are truncating knowledge in an unnatural and myopic manner. Thank you, Kir Komrik — Preceding unsigned comment added by 75.210.255.194 (talk) 19:13, 5 November 2012 (UTC)

Yes, this is the correct place to respond, and thank you for doing so. Whether or not you think it is reasonable, the policy is that blogs are not considered to be a reliable source. If you think an exception should be made in this case, the burden of proof is on you to convince the other editors of that. The purpose of Wikipedia is to hold a summary of notable information from all branches of knowledge. Its job is not to advance the research of fusion power or to promote any particular ideas, no matter how good they are. If you want to include your ideas here, you must first attract significant attention to them on the outside. Once other people start writing about your ideas, then they can be discussed in this article. (I've tried twice to look at your article, but I got bogged down. It lacks a decent summary.) Art Carlson (talk) 20:51, 5 November 2012 (UTC)

:: Thank you for the response. Overall, I can only say, "fair enough". I will work on a better summary and wait until it percolates up in google. But I can tell you this, this is a real program funded by real serious money worked on by real physicists who are real convinced a major breakthrough has occurred that rests squarely on the considerable amounts of research previously in magnetohydrodymanics and tokamaks. Unfortunately, it is being researched by a very secretive industry. The sad truth is that gobs of money (literally billions) can be thrown on something like this privately when public projects like ITER get nothing by comparison. I am in a position to discuss some aspects in public and I will do that in hope of garnering the interest you referenced - kk Art Carlson (talk) 20:51, 5 November 2012 (UTC)