Talk:Aneutronic fusion

Untitled

• Talk:Nuclear fusion/Annotated bibliography of p-B11 fusion is a somewhat dated (1998) list of references with my (POV warning!) comments on them. It doesn't have a clear place in this article, at least in the present form, but I thought it might be useful enough to be pointed out here. --Art Carlson 10:16, 8 September 2006 (UTC)

Consistent data set

Independent of the blood being shed on the front, I would like to come to an agreeement on the data we use, starting with <σv> as a function of temperature. The numbers I use are verifiable, but I think they come from multiple sources and may not be entirely consistent. Can we agree to use the functional form and coefficients given in

Cox, Larry T., Thermonuclear Reaction Bibliography with Cross Section Data for Four Advanced Reactions.,
AF-TR-90-053, Edwards Air Force Base: Phillips Laboratory Technical Services Office, 1991

and reproduced here? I'm open to other suggestions. --Art Carlson 08:19, 27 September 2006 (UTC)

New proposal for power density

(To avoid confusion, please limit comments in this section to the proposal above. Comments on other content should be put in the appropriate section. --Art Carlson 08:40, 3 October 2006 (UTC))

In every published fusion power plant design, the part of the plant that produces the fusion reactions is much more expensive than the part that converts the nuclear power to electricity. In that case, as indeed in most power systems, the power density is a very important characteristic. If the power density can be doubled without changing the design too much, then the cost of electricity will be at least halved. In addition, the confinement time required depends on the power density.

It is, however, not trivial to compare the power density produced by two different fusion fuel cycles. The case most favorable to p-B11 relative to D-T fuel is a (hypotheical) confinement device that only works well at ion temperatures above about 400 keV, where the reaction rate parameter <σ'v> is equal for the two fuels, and that runs with low electron temperature. In terms of confinement time required, p-B11 would even have an advantage, because the energy of the charged products of that reaction is two and a half times higher than that for D-T. As soon as these assumptions are relaxed, for example by considering hot electrons, by allowing the D-T reaction to run at a lower temperature, or by including the energy of the neutrons in the calculation, the power density advantage shifts back to D-T.

The most common assumption is to compare the power densities at the same pressure, with the ion temperature for each reaction chosen to maximize the power density, and with the electron temperature equal to the ion temperature. Although confinement schemes can be and sometimes are limited by other factors, most well-investigated schemes have, not surprisingly, some kind of pressure limit. Under these assumptions, the power density for p-B11 is about 2100 times smaller than that for D-T. If the device runs with cold electrons, the ratio is still about 700.

Are there specific objections to (1) the factual accuracy, (2) the point of view, or (3) the editorial style of this version? I tried to do justice to the complexity of the issue without being long-winded. Inline citations would be desirable. Footnotes could be used to add information or to reduce the length of the main text. We can talk about the exact values I used for the numbers. --Art Carlson 08:48, 2 October 2006 (UTC)

To make myself perfectly clear, I consider this expanded version to be adequate reply to Eric's objection that the two-sentence version did not do justice to the complexity of the issue. I will leave it here for a few days, during which time I consider Eric (or any other active editor) obligated to detail any objections. If no comments or suggestions are made (in enough detail that they can be responded to), I will consider this the consensus version, put it on the live page, and defend it against unargued or blanket reverts. --Art Carlson 09:48, 2 October 2006 (UTC)

Sure, Art, there is a lot wrong with that factually. First is the assumption that in any fusion device the cost is dominated by energy production, not conversion. That is the case for tokamak, but not, for example for the DPF. A tokamak without energy conversion that is capable of producing a GW of energy will, by any estimate I know of, have a capital cost in excess of $2/W, probably a lot in excess. A DPF, without energy conversion equipment, that is capable of reaching the breakeven conditions outlined in my own published research costs about $150,000 with current low production rates of components such as capacitors and fast switches. (This figure can be easily verified since I have priced the components myself.) It would be capable of producing 5 MW of net power, so has a cost of about $0.03/W. In that case the total cost is dominated by the cost of conversion, which would be around $0.80/W for thermal conversion, but probably around $0.10/W for direct conversion, again based on low-volume production.

A careful reading of what we both wrote shows that there is no disagreement on the facts. Since you evidently misunderstood me, we obviously need to work on the clarity. I first point out that the costs in published fusion power plant designs, like the tokamak designs you mention but not limited to them, are dominated by the nuclear island. I do not doubt that you have made some estimates for a DPF plant that are dominated by the balance of plant.--Art Carlson 21:18, 3 October 2006 (UTC)

Second, the power density of the reacting plasma does not have a direct link to costs. In the DPF, the reaction takes place in a volume that is tiny compared with the total size of the device and in a time that is a small fraction of the pulse repetition time. Therefore comparing power density in a DPF to that of a tokamak would give an estimate of relative cost that would be many orders of magnitude in error.

In other words, a DPF can produce enormously higher pressure per dollar than a tokamak. But the cost of power is not in the same ratio, although the DPF would be about two orders of magnitude cheaper.

It is tempting - but, as you point out, invalid - to estimate the output of a fusion plant by multiplying the fusion power density with some volume such as that of the reaction chamber. This is one of many reasons that, as we both agree, power density figures are totally useless to compare different power plant concepts like tokamaks and DPF. That is why I have never done so. My text specifically compares "two different fusion fuel cycles". So again, on a careful reading, we do not disagree on the facts.--Art Carlson 21:18, 3 October 2006 (UTC)

So altogether, the paragraphs are not accurate. Nor is the paragraph that you have, for the same reasons, so I am going back to my paragraph, which is accurate.Elerner 02:29, 3 October 2006 (UTC)

Now that it is clear that the problem lies more in understanding what I wrote, perhaps you can suggest a version that you find clearer? --Art Carlson 21:18, 3 October 2006 (UTC)

It has now been 9 days since I posted this proposal and 8 days since the last comments were made. Therefore I have incorporated it into the article. Improvements are welcome, but blanket reverts are out-of-place, --Art Carlson 08:06, 11 October 2006 (UTC)

Eric's justification for his reversions

Since Eric seems to have difficulty focussing on detailed arguments, I have created this section to give him a leg up. Specifically, he has several times made a reversion essentially identical to this one. I provide space here for him to explain why he made each of these changes. --Art Carlson 20:56, 3 October 2006 (UTC)

1. It is better not to provide a wiki link to the Lawson criterion when discussing the Lawson criterion because ...

2. It is better not to provide a wiki link to a calculation of the confinement requirement for D-T vs. p-B11 when discussing the confinement requirement for D-T vs. p-B11 because ...

3. It is better not to provide a footnote explaining the hot ion mode, even though two of the three mechanisms discussed later for achieving p-B11 ignition use this mode, because ...

4. It is better not to provide a reference for the idea of bremsstrahlung absorption in pellet fusion because ...

5. It is better not to disambiguate the wiki link Pascal to Pascal (unit) because ...

This argument is not worth the time devoted to it. I have merged part of your paragraph with part of mine. I will narrow my objection to the fact that your claim that one measure is most imortant is totally unsourced and is your own original opinion, so does not belong there. Find a citation for it and then say "according to so and so..." other wise drop it.Elerner 18:33, 9 October 2006 (UTC)

I can live with that. Speaking of dropping it, I guess you saw the light about points 4 and 5. I'm still looking forward to hearing your reasons for maintaining points 1 through 3, though. --Art Carlson 19:14, 9 October 2006 (UTC)

oh, put them back in yourself without reverting and let's end this!Elerner 20:58, 9 October 2006 (UTC)

Glady. Just for the record, there were eight rounds of reversions due to these differences, which you now concede without having once justified them. I hope we can work more efficiently in the future. --Art Carlson 21:18, 9 October 2006 (UTC)

edits by EngineerScotty

You may not be aware of this, but aneutronic fusion has been studied in the laboratory for decades. The fact that it produces the bulk of its energy in charged particles is vaidated by thousands of experiments. To portray, as you do, known, undisputed physics as the opinions of a minority is a gross distortion. I don't want to get into a revert war again, but I think you should do a bit of research before piling in on this. I stronlgy suggest you rever the changes yourslef until you look a bit at the field.Elerner 00:41, 10 November 2006 (UTC)

Got your note--I have an interesting perspective on the article that you might consider--it might explain better the reactions of some on Wikipedia (and outside as well).

Adding references to the article would be good--inline references would be better. At any rate, processes or technologies which have been proposed--even if studied in detail--but which haven't been built, probably should use the subjunctive voice. I'm not at all equating the topic with perpetual motion machines (as WAS 4.250 did on the arb page), but many agree the technical hurdles are immense.

I should let you know that my professional line of work (a software engineer) has long taught me to be skeptical of claims which are based entirely on theory and not on practice (here being empirical research)--with exceptions granted for things like mathematics.

I'm not doubting the scientific claims at all, nor am I agreeing with them. I have no intellectual basis to do so, not being a physicist. I pretty much left them alone. However, when the article ventures forth from the purely theoretical, into questions of "how can we build a device which uses this far-off technology, how much will it cost, and what will other properties of this thing be", it crosses a big bright line from theoretical science into engineering--my turf. Discussing engineering parameters of device which we currently have no idea how to harness the underlying technology of, and speculating on its properties, while using the present tense--strikes me as highly inappropriate.

My preference for this article, after much reflection, would be to remove most if not all claims concerning the properties of a powerplant based on aneutronic fusion. Such engineering analyses are far too speculative to include in an encyclopedia at this state of the underlying technology (infancy), regardless of the soundness of the underyling science. The information on the underyling physics--the various reactions and their properties, what aneutronic fusion is--certainly should stay. The science parts of the article aren't bad (better sources would be nice), but the detailed commentary regarding how a reactor and energy conversion device might work are simply pie-in-the-sky at this point. If you were to get a multi-billion-dollar grant to study this, Eric, I suspect you'd be at least a decade away from having a laboratory reactor up and running, let alone being able to prototype a powerplant (let alone being able to build one that is cost-effective). To make claims--even couched as speculation--as to how efficient such a beast would be, is simply not appropriate here. And--not to be rude--it does look like a sales job.

Thoughts from others?

--EngineerScotty 01:24, 10 November 2006 (UTC)

I'm following this, and thinking about it. Fred Bauder 01:50, 10 November 2006 (UTC)

Might it become a principle in the case? :) --EngineerScotty 01:52, 10 November 2006 (UTC)

But your edits are flat-out wrong. Of course aneutronic fusion reactions have been produced in the laboratory. It is not a proposed form of fusion power--it is a well-known form.

Again, you're intermingling the raw science, with the technical application. Aneutronic fusion is certainly a well-known form of fusion; but it remains a "proposed" form of fusion power--nobody's built a functioning powerplant that operates using aneutronic fusion.

If you are trying to say that it has not produced net energy, that is true of all forms of fusion energy.

From the article, the only mention of an actual aneutronic reaction being produced is this passage: "In 2005, a Russian team produced hydrogen-boron aneutronic fusions using a picosecond laser[13]. However, the number of the resulting α particles (around 103 per laser pulse) was extremely low." Never mind being able to recover positive net energy--has anybody even sustained a chain reaction yet?

Fusion reactions are not chain reactions. You are thinking of fission--that is a different process. Please learn just a bit of the physics before chopping up the article.Elerner 02:10, 11 November 2006 (UTC)

Yet fusion engineering is an active field of study--there are whole departments devoted to it at some universities. It is not theory that aneutronic reactions produce almost all their energy as charged particles--it is undisputed laboratory findings for decades past.

That appears to be by definition.

If you eliminate from this article all discussion of engineering problems, you would have to knock out 80% of the article on fusion power, which deals with engineering problems of tokamaks.

A better solution, I think, would be to separate the aneutronic fusion and aneutronic fusion reactor--one could focus on the science, the other could focus on efforts to harness this sort of reaction.

Again, this article was gone over with a fine-toothed comb by Art Carlson, who is no friend of aneutronic fusion. Please don't take a bull-in-china-shop approach. Again I offer to provide review articles so you can see what the state of the field is.

Please. Also please note that you and Art do not constitute a consensus. While your work to improve the article is appreciated; many of us think it could be improved further.

Also we do not need a half billion dollars because the devices cost less than $300,000 to build. Many have been built--this is not theory this is ongoing experimental work dating back decades.Elerner 02:00, 10 November 2006 (UTC)

Which devices, exactly? And with what properties?

--EngineerScotty 17:55, 10 November 2006 (UTC)

Dense plasma focus is one device that is very cheap to build and has been researched experimentally for over forty years. This is not a new field--it is an ongoing program. Elerner 02:10, 11 November 2006 (UTC)

Elerner 02:00, 10 November 2006 (UTC)

I don't get this, "power," to me, means sustained output. This is a reaction, but not power. Fred Bauder 02:42, 10 November 2006 (UTC)

This is not correct. Power in science and engineering has a very specific meaning—energy produced per unit time. Fusion devices can produce power either continuously ( which has never been achieved, but is theorized as possible with some devices) or in pulses that are repeated. Aneutronic fusion is just another form of fusion energy from the more commonly studied DT reaction. It is no more theoretical than DT and has been studied experimentally very extensively. Fusion power has been produced in many devices and aneutronic fusion power has also been produced.

You are confusing “power” with “net power production”. That is very different. This is when you get more power out of the device than you put into it. This has not been achieved for any controlled fusion device

If you look at the “fusion power” article, you will see power is correctly referred to. None of the devices mentioned come at all close to producing “net power production”: more power produced than electricity than is needed to run the device. But they all are correctly described as producing power.Elerner 03:52, 10 November 2006 (UTC)

Still confusing. I know the Amazon is a "stream", but I don't think that's even mentioned in Amazon River. Fred Bauder 13:00, 10 November 2006 (UTC)

Did you look at the fusion power article? Rivers have nothing to do with this, but fusion power does. Please look at it and see the correct use of the terms.Elerner 02:10, 11 November 2006 (UTC)

I think the best approach to this article is that I will provide, over the next few days, additional verifiable references to everything that I can. Then you can get rid of things that are not cited? How about that?Elerner 02:10, 11 November 2006 (UTC)

I'm not very happy either with a lot of the edits by EngineerScotty. Unfortunately I won't have time before Thursday to go through them in detail. --Art Carlson 18:03, 11 November 2006 (UTC)

It seems that EngineerScotty struck my bogosity-meter with the simple statement, "If you were to get a multi-billion-dollar grant to study this, Eric, I suspect you'd be at least a decade away from having a laboratory reactor up and running". It is now less-than four years later, Eric has received a thousandth this amount of funding, and has his laboratory reactor. Perhaps the problem is, that vast amounts of funding actually slows research down? -- 99.233.186.4 (talk) 13:17, 15 August 2010 (UTC)

I think this section is wrong...

In the candidate area I found this passage:

"The next two reactions are usually treated as a chain in the hope of attaining an enhanced reactivity due to a non-thermal distribution. The product 3He from the first reaction..."

I believe this needs to be fixed. The first reaction has no 3H3 product, nor does the first reaction on the list. I think this needs to be re-arranged.

Maury 22:28, 16 November 2006 (UTC)

The reactions in question are

p	+	6Li	→		4He	(1.7 MeV)	+		3He	(2.3 MeV)
3He	+	6Li	→	2	4He		+		p	+ 16.9 MeV

Add them together and you get

2 6Li → 3 4He

I suspect you were confused about which reactions I meant. Would it be better to number the reactions? --Art Carlson 09:09, 17 November 2006 (UTC)

I made some changes that might make things clearer. --Art Carlson 09:27, 17 November 2006 (UTC)

Yes, much better now. Maury 13:21, 23 November 2006 (UTC)

References in section on "Technical challenges"

We now have 12 inline references in fifty-some lines of text in Aneutronic fusion#Technical challenges. Do we still need the {{References}} template? --Art Carlson 10:00, 17 November 2006 (UTC)

Contradiction?

In every published fusion power plant design, the part of the plant that produces the fusion reactions is much more expensive than the part that converts the nuclear power to electricity.

This equipment is sufficiently expensive that about 80% of the capital cost of a typical fossil-fuel electric power generating station is in the thermal conversion equipment.[citation needed]

Not really a contradiction, but the latter seems irrelevant. — Omegatron 00:46, 23 November 2006 (UTC)

Actually I think with some re-wording this is actually useful information. If the second sentance is correct, and I believe it is, then it would seem the capital costs of a fusion plant would be very different, and that seems to be worth mentioning. That said, I'm not sure this is the proper article to do it in! Maury 19:04, 23 November 2006 (UTC)

Odd question, but... Why is Bussard pushing aneutronic fusion?

I realize this might not be the right place to ask this, but it seems to be getting everyone's eyeballs, so...

Why is Bussard pushing aneutronic fusion? And for that matter, why does it seem that everyone with a "non-conventional" design (of which there are only a few, admittedly) always push aneutronic devices? Don't get me wrong, there are major advantages here that are evident to all, but given the fact that we're nowhere near ready to commercialize any design, wouldn't it be prudent to test using D-T to start with? Any of the reactions mentioned here are much more difficult to get working, so it would seem to me that any machine capable of supporting aneutronic fusion should be able to generate much higher rates using D-T, at least for a short time (embrittlement, etc.)

Is there some feature of the alternative designs that precludes this? As far as I am aware the initial fusion experiments in both the fusor and the migma used D-T, so I don't see any problems there. I don't fully understand Bussard's new design, but it doesn't seem to have any major differences that would require higher mass ions or anything that obvious like that.

Bussard's Polywell design uses Inertial electrostatic confinement which depends on the concept of wiffle-ball confinement. This effect has recently been demonstrated. Now this is particularly suitable for Boron-11 + proton aneutronic fusion because we don't want two similar nuclei to smash into one another in a plasma as we do with D-T, what we want is for protons to smash into Boron-11 nuclei. We can possibly have the Boron-11 nuclei plasma at relatively low temperatures inside the wiffle-ball and fire protons accelerated by compact plasma acceleration at that target. — Preceding unsigned comment added by Hal2k1 (talk • contribs) 12:39, 12 August 2015 (UTC)

Is there some sort of economic or legal issue here? Or is it, as it appears to these untrained eyes, a way of avoiding having to demonstrate the machines actually work at a small scale before moving on to the full-sized devices?

Maury 19:01, 23 November 2006 (UTC)

There are three good reasons: 1) everyone knows tokamaks have not a prayer of ever doing aneutronic reactions, so it's a differentiator, 2) aneutronic reactors would potentially eliminate the thermal cycle, which would remove a very large amount of the power loss that thermal-driven power plants suffer, in addition to being more economical due to containment issue, and so 3) a commercially viable fusion power source would probably have to be aneutronic (these guys always want money, and VC funders require something more than a cool science project -- and yes, there really is VC money out there for IEC fusion). If you had a reactor design that could do both, you could reasonably regard D-D/D-T as a waste of time and money. OTOH, there is approx zero chance a "full-sized device" would be built without a small demo first (and as with Bussard's current (posthumous) effort, those almost certainly will burn D-D/D-T, not p-B11 or other aneutronic reactions) 24.13.35.175 (talk) 00:25, 22 January 2008 (UTC)

I never understood that either. There is certainly no compelling technical reason. (Psychologically, I suppose once you start divorcing yourself from reality there is no reason not to go whole hog.) When I brought up the advantages of using D-T in a dense plasma focus, Eric Lerner reacted very allergic. --Art Carlson 08:42, 24 November 2006 (UTC)

Hmmm, not a very scholarly critique, but I suppose once you divorce yourself from objectivity there is no reason not to go whole hog. 24.13.35.175 (talk) 00:25, 22 January 2008 (UTC)

Bussard's experiments are D-D fusion, and he talks about burning up conventional nuclear waste in the neutron flux from D-T fusors. He also talks about retrofitting conventional power plants by tying the steam lines to external boron-blanketed D-T fusors. I don't understand why everyone's so hard on him when they clearly haven't paid any attention to what he's actually doing.

He clearly states that his proposed demonstration prototype would cost $150M for D-D or $200M for p-B11 and that the Navy is more interested in p-B11 for electric boats. He definitely likes the idea of aneutronic fusion (as anyone would), but it doesn't sound like he's being irrational about it to me.

He also emphasizes that the resulting alpha particles could be neutralized by grids to generate DC directly instead of the inefficient heating things up with neutrons and boiling water. I don't know if that's possible with other reactions. — Omegatron 23:34, 24 November 2006 (UTC)

Primary competing reaction is "absorb p, emit neutron" or <p,n>. Since B10 + n > B11* > alpha + Li7 and fast protons can provide this energies in elastic collisions with the nucleus. Both p & n are ~2000x electron mass. TaylorLeem (talk) 18:34, 25 June 2020 (UTC)

p+6Li fusion efficiency?

The second paragraph doesn't give a very convincing explanation why this reaction chain is impractical:

p + 6Li   → 4He (1.7 MeV) + 3He (2.3 MeV)
3He + 6Li → 2 4He + p + 16.9 MeV
3He + 3He → 4He + 2 p

All it says is that the non-thermal distribution of 3He provides an insufficient enhancement to the later stages. Is the cross-section of 3He+6Li too low? Does electromagnatic repulsion require too high a reaction temperature? Can someone elaborate or reword this section a bit? --Dgies 21:04, 4 December 2006 (UTC)

Fusion power wikis give low req energies for T+D and higher for He3 + D (= He4 + p) and D + D reactions (giving He3+n). Fusion generates a nucleus with too much energy to be stable hence like U236m it needs to fission or lose the energy via gamma ray. Small n atoms are much less likely to emit a gamma so a particle is emitted. Note that reaction of 2 He3 generates 3 products which work against the high pressure already required to react. Note that (per 'neutron source' wiki) Deuterium splits at 2 MeV and Lithium 7 loses a neutron ~1.5 MeV. TaylorLeem (talk) 16:16, 25 June 2020 (UTC)

Note Lithium is used in nuclear weapons because at thermonuclear reaction temperatures it breaks down ino He4 + Tritium. TaylorLeem (talk) 16:21, 25 June 2020 (UTC)

Given Densities?

"For given densities of the reacting nuclei, the reaction rate for hydrogen boron achieves its peak rate at around 600 keV (6.6 billion degrees Celsius or 6.6 gigakelvins) while D-T has a peak at around 66 keV (730 million degrees Celsius)."

What are these "given densities" that the article speaks of, and why are they the important ones for aneutronic fusion such that the article mentions the (I assume) ion energy of the p11B peak for these particular densities and no others. -- TristanDC 20:51, 4 January 2007 (UTC)

It means, choose any densities you want, but keep then constant while you vary the temperature. No matter what densities you take, you will always find the maximum reaction rates to be maximum at 600 keV and 66 keV respectively. --Art Carlson 09:55, 5 January 2007 (UTC)

I'm going to change the wording to "For any given density of the reacting nuclei, ..." -- TristanDC 20:24, 6 January 2007 (UTC)

MHz theta pinch

Bp fusion engin thepry by MHz theta pinches plasma focus fybrid Toyokawa High Phyisics Labratory, Japan T&F 0533-87-3880, Shigetaka Ikegami

10~-6Ω　one turn resistance MHz strong magnetic field C-L resonance elements bundle first mode coil, 1m dia., is easy. It is found that linear relation between coil conductance and elements number is hold for C capacity part with air or gass space, as well as L fine coated wires number.　Vortex Jule loss is constant for 0.01mm dia. coated steel wires number. Theta pinch and plasma focus system hybrid is easy.

By Bp fusion engine the sea containing boron becomes more than oil. By BxJ acceleration of expanding magnetic field mat piston, 200～600kev velocity snowplow plasma of high density 10ev is possible. Skin current Jule heat is recovered by heat cycle. During acceleration and expansion, plasma is recombined with hｖ radiation. It is efficient to acclerate low density large volume ｐlasma by large width cylinder boundary, with slops for plasma slips to center boundary. At pinch, leaks from both plasma ends are impossible by composited millor magnetic field of skin current and axial focus current. Adiabatic compression without shock is considered. And verfied with shallow water suimlation experiment. High density is confitmed with isothermal ionizing cooling compression. High density small quanrity plasma dia. is vey very small. Pinch time, solitary wav pass time through pinched plasma, is vey small so that electron radiation is small. Fusion energy is larger than sum of all losses. Fusion energy, compressed plasma energy and piston magnetic field energy are compleatly recovered every MHz cycle by piston withdrow. Fusion pulses series generates power with efficiency of abou 0.6～0.7.

--(Contributed on 05:18, 2007 March 12 by user 211.129.222.223)

This is so incomprehensible that it is impossible to refute. More to the point, the citation of the source (if indeed that is what it is) is also incomprehensible. With all reluctance to revert without detailed discussion, I have no other choice here. --Art Carlson 11:34, 12 March 2007 (UTC)

OK. It looks like the ref. is S. Ikegami, "A new type of low-loss, strong-field RF coil for commercial nuclear fusion", Electrical Engineering in Japan, Vol.111, No.4, 1991, pp. 52-59. I can't find it online. I can check, but I doubt that it's in our library. Has anyone read this? Can anyone vouch for the reliability of the source? (peer-reviewed? conference proceedings?) Can anyone justify why this particular article/concept is notable enough to be singled out in this article? (Does this paper have a significant number of citations? Is the author a well-respected expert in the field of fusion energy?) Finally, assuming positive answers to these questions, the language and NPOV are so poor that they would have to be cleaned up before going live. --Art Carlson 09:16, 15 March 2007 (UTC)

There are full text issues of EEJ online here, but they only go back to Vol 118 (1997). If that is the most recent (perhaps the only) publication on this concept, that is an additional indication that it does not come from a reliable source. --Art Carlson 11:40, 20 April 2007 (UTC)

Sorry. I messed up that last edit summary. I wanted to say that Wikipedia doesn't care about aneutronic fusion one way or the other. What Wikipedia wants is well-written, informative articles, based on reliable and verifiable sources, from a neutral point-of-view. --Art Carlson 08:56, 20 March 2007 (UTC)

Edits from folks who aren't logged in and aren't really good with English

I've noticed that there are edits here that are probably very interesting but aren't written well enough to keep. Unfortunately, that seems to be making alot of work for Art. I would ask that whoever is doing those edits to seek a friend who speaks better English or to put your contributions on the Japanese wikipedia. Here are the IP addresses that have been loading down this article with hard to understand edits:

210.249.100.16 
211.129.222.223

Temperature or velocity?

I am not a physicist, but from what I understand, the idea behind Polywell is that high velocities can be reached without high temperatures, which would enable p-B11 fusion. So should this:

To begin with, hydrogen-boron fusion requires ion energies or temperatures almost ten times higher than those for D-T fusion.

Be changed to emphasize velocity? — Omegatron 14:52, 17 May 2007 (UTC)

That quote is correct. Temperature is somewhat misleading, but essentially no different. Ion energy (eV) and temperature (K) are interchangeable, except that temperature is usually referring to the average energy of a whole species of particles. A Polywell is a hot fusion device. You would not want to stick your hand in the plasma (if that were even possible). The idea is the same as any other IEC device. Instead of using ECR heating to increase the average velocity (I.E. temperature) of a magnetically confined maxwellian plasma to the point where significant fusion occurs, you set up an electrostatic potential well to accelerate ions to the optimal velocity for fusion. This creates a nearly monoenergetic (non-maxwellian) plasma in the reaction area. Instead of increasing the energy of the whole plasma, it manipulates the plasma to move the high energy ions together. — Blane Dabney 20:57, 31 May 2007 (UTC)

Helium-3 Abundance

The article states that Helium-3 provides a fuel supply problem but its abundance on the moon is relatively higher, some fraction of a part per million. The words relatively higher link to the helium-3 page which states its natural abundance as 0.00013% or so. If i'm correct, that works out to 1.3 ppm which would make helium-3 much more abundant on earth, so either this article or the helium-3 nat. abundance figure is incorect! -ZMiller —Preceding unsigned comment added by 24.183.44.109 (talk) 12:21, 8 March 2008 (UTC)

One figure refers to the fraction of all the stuff in the material on the Moon's surface that is Helium-3. The other figure refers to the fraction of all Helium atoms, wherever they occur in the Solar System, which have the isotope number 3. The numbers are in no way comparable to each other. --Art Carlson (talk) 12:47, 8 March 2008 (UTC)

Conditional case used where positive statements /should/ be made (pun intended)

There are a lot of "could"s, "should"s, and "would"s in this article which should refer to who thinks these things might be the case and why. As it is it reads like journalism. I know a lot of those parts were written by a former science journalist so it's to be expected, but it could do with being made more sure of what it's saying. I suspect that a good few fact tags will have to show up when they are changed. Does anybody agree that these sentences should be bolder about what they are saying and fact tags should be added? TristanDC (talk) 02:37, 24 March 2008 (UTC)

"Proposed economic benefits" section

I have reverted this edit, which introduced a new section titles "Proposed economic benefits". The content rejected is reproduced here, with my detailed objections interspersed.

The potential of this approach towards achieving net gain of fusion energy in an economical way consists of the following :

• a proposed conventional fusion reactor utilizing deuterium-tritium fuel produces neutrons that create heat, thus the energy will require expensive turbines and generators to form electricity, opposed to the focus fusion approach where the energy is released mainly in the form of a high energy pulsed beam of helium nuclei, being already electric current , thus no expensive thermal conversion is needed , no expensive turbine , pressurized equipment

There is already a section in this article on Direct conversion of energy.

• the reactor utilized is small and cheap in comparison to ( nuclear reactors , coal power stations , fusion tokamak reactors)

The claim that reactors using aneutronic fuels will be small and cheap - or that they will work at all - is rejected by almost all fusion researchers. The connection between alternate confinement concepts and alternate fuel cycles is in most cases very tenuous.

• cheap , extremely condensed and abundant fuel is used

This is a benefit of fusion power generally, not something special about aneutronic fusion.

• no radioactive waste issues, since no neutrons are produced as by-product

There is already a section in this article on Residual radiation from a p-11B reactor.

• no fossil fuel related issues and hidden society costs ( although worldwide carbon taxes are not officially paid the use of fossil fuels does create additional costs to society, such as all the diseases, caused by coal burning toxic by-products, climate change etc. )

This is a benefit of fusion power generally, not something special about aneutronic fusion.

• the proposed power station will be base-load with comparably height availability. The small size of the units will enable their massive production and rapid ramp-up

Whether a power plant is more economical when it runs as base-load or load-following is debatable. The availability of a fusion power plant is tightly related to the confinement concept, and loosely if at all related to the fuel cycle. Claims of "small" were dealt with above.

--Art Carlson (talk) 07:54, 29 April 2010 (UTC)

Our edits crossed. The section was in the version I started editing, and the serializer apparently didn't notice when I saved my changes. I have no objection to killing the section... Lfstevens (talk) 04:06, 1 May 2010 (UTC)

Oh. Sorry to suspect you of being evil. Strange that you didn't see an edit conflict, but shit happens. I thought about leaving the copy edits, but I wasn't sure about some of them anyway.

• Since there is a separate article (albeit stubby) on lithium-6, and a section in an isotopes-of articles for lithium-7 and boron-11, why do you think it better to link to the article on the element in general?
• Are you sure that "p–⁷Li" (without a space) looks better than "p –⁷Li" (with one)?
• I'm not sure, but I believe that the title of the article by Kernbichler et al. uses a superscirpt (p–¹¹B). Why did you want to change it?
• Are you sure that "n - 2.8 MeV" looks better than "n − 2.8 MeV"?

My main concern is the content, so if you are confident of your copy edits, I certainly won't revert them next time. --Art Carlson (talk) 07:30, 1 May 2010 (UTC)

I have no opinion on the punctuation. I was just trying to smooth the wording and make it more parallel. I'm also not knowledgeable on this subject which is why I tried to stick to copy-editing. Lfstevens (talk) 20:13, 1 May 2010 (UTC)

Suggestions for the last section

Since I am a layperson, I cannot implement changes myself, but I think the section on "Direct conversion of energy" could be improved in a couple of ways.

i. A wikilink could be added to each of the mentioned conversion techniques, since they are not obvious. For example, I would like to know more about microwave technology that would enable harvesting the energy from an aneutronic reactor. As for electrostatic methods, do they mean Electrostatic generators? If so, it is not obvious from the relevant link how they could be applied to the case. The same applied to inductive techniques, although this case is more down to earth to the eyes of a layperson (after all, the basic laws of electromagnetism are a common topic in Secondary School).

ii. They say that aneutronic reactors generate most of their energy in the form of charged particles. I can see that in the case of the protrons in the first, fourth and fifth reactions in the candidate section. But the remaining reactions only generate uncharged atoms such as helium and carbon. Where would the energy come from in these cases, which include the p-B reaction? Plus, what is the form of the electromagnetic energy that is released by the reactions (the MeV numbers in brackets next to each one)? Is this just heat (i.e., infrared radiation), or is it a more coherent wave such as X-rays, gamma rays, visible light etc., that can be harvested as well? —Preceding unsigned comment added by 144.92.43.122 (talk) 21:07, 23 July 2010 (UTC)

Questions? Comments.

1. Aneutronic here seems to be reactions that do not generate neutrons to the outside world or are we talking no contamination (reactor structure) whatsoever. Would seem that n + 10B > 11B* > 7Li + 4He generates energy without producing neutrons.
2. This article seems to concentrate on magnetic containment methods that, for all the excessive energy input, can't get more than a few percent conversion.
3. Example the p + 11B reaction: are the energy thresholds from actual fusion reactions or proton beam tests or what?
4. 1H + 11B > 12C* > 3 4He We do some engineering testing and have a "tube head" type X-ray for metals that will max out just under an MeV. The asterisk on the previous equations refers to the high energy metastable isotope e.g. 236U is stable but 236U* (from n + 235U) fissions. 9Be generates neutrons when exposed to x-rays, can we generate energy or initiate reactions with x-rays on 7Li? 6Li + n > 7Li* > 4He + 3H + 4.7 MeV and 7Li + n > 6Li + 2 n + 3 MeV. The Thermonuclear Wiki section notes that most of the 238U fission and Li fusion reactions were caused by x-ray and gamma from the initiator.
5. See neutron Source Neutron Generator and Fusor Wikipedia articles also including ion beams for p + 11B reaction. Notes high efficiency of D_T reaction with 160KeV ion source.
6. Industrial size ion generators: c.f. the Thyratrons used to commutate (DC to AC) the 1400 Megawatt 500KV DC lines from Bonneville dam to California.
7. Find any proton absorbtion cross sections? Apparently 9Be + 1H > 2 4He + 2H has a low ion beam voltage threshold.

Shjacks45 (talk) 01:10, 24 July 2010 (UTC)

i have nothing to add except for (1), that because neutrons are unstable, they have to come from somewhere, so n + 10B > 11B* > 7Li + 4He isn't aneutonic after all. -- 99.233.186.4 (talk) 14:21, 15 August 2010 (UTC)

Fusion misnomer

Surely p+B, p+Li and p+N are fission reactions, not fusion reactions. The products have lower atomic number than the fuel. That p is an element is irrelevant: the fission induced by p hitting U238 is always referred to as fission, not fusion. Qemist (talk) 05:03, 29 June 2011 (UTC)

There is a brief thread on this on Talk:Nuclear fusion. If you want to discuss this further, that article is probably a better place. The upshot is that you can make a case to call it either one, but everybody has been calling it fusion for decades, so Wikipedia will too. --Art Carlson (talk) 07:23, 29 June 2011 (UTC)

Totally agree. No matter how many people in how many places keep calling this a fusion reaction (because it sounds fancier and because fission has come to be associated with radioactive byproducts), this is nevertheless a fission reaction. All that matters for fusion is that small particles enter and a big (stable) particle emerges - as in stars. Boron getting bombarded by protons in order to break it into Helium, is fission. 190.25.37.118 (talk) — Preceding undated comment added 13:54, 1 February 2022 (UTC)

At the risk of sounding weird : cold fusion - 2 Japanese articles

Consider underground oil versus "methane hydrate". We have "proven" oil reserves yet, even though there is estimated to be ten times that energy in gas hydrates, all we hear of methane hydrate are disasters attributed to it.

Muon mediated fusion via tunneling is a given, yet due to foolish attempts to duplicate "excess heat" generated in an open system delegates "cold fusion" to the scrap heap of history. With some experience in metals testing and trace analysis, (and having come from one of the few schools with a reactor on campus) the claim of Deuterium fusion seems unlikely. However the reaction conditions for the testers who reported success all seemed to required Lithium in alkaline Deuterium Oxide at high currents. The H-H bond requires 104KCal/Mole to break yet only a gentle pressure is required to force Hydrogen through a Palladium disk. At higher Hydrogen pressures pure Palladium can exhibit an explosive phase change. I have worked on high pressure (50,000 psi) Palladium Hydrogenations. Purportedly the Deuterium nuclei exist interstitially surrounded by the metallic electron cloud which like the Muon, theoretically allows close approach by the nuclei especially if they both occupy the same interstitial location, say at a deformity, their close approach allows tunneling of a nucleon. The reaction conditions however are similar to Copper plating where I observed Potassium diffused several microns into the Steel underlying the Copper plating. My experience tells me there is something occurring between the Deuterium and the Lithium. Weather Balloon (like from Area 51) Hydrogen Generators used 1 mm Pd(Ag 5%) membranes to purify Hydrogen as that alloy didn't fracture like pure Pd. Of course can't test with ⁶Li, it is illegal. Unlike Deuterium and Lithium, Helium is immobile in the Palladium lattice, and has been noted when Pd cathodes were sacrificed. I cannot abide the "excess heat" argument because of electrical energy entering the system unmonitored and gaseous Hydrogen and Oxygen escaping the system, but no matter how impure there is no way to explain the Helium in the Palladium.

My reason for going into this much detail is two well documented Japanese articles. One which proved that Lithium with normal water, normal Hydrogen, did not show excess heat, or other sign of reaction, until Borate was added. Note that the first historical discovery of Boron was electrolysis of aqueous solution of Borate. The second note was Electrolysis of (alkaline) Potassium Hydroxide solution at high currents using Nickel cathode and normal water. The reacted cathode on dissolution showed traces of Calcium but the control cathode did not.

Consider: there are major differences between the reactivity of ²³⁵U and ²³⁸U to thermal neutrons and fast neutrons and X-rays. (From 10-15% of a reactors power comes from fission of 238 from fast neutrons; 40% of the energy of a "Hydrogen Bomb" comes from Gamma rays causing ²³⁸U fission. Binding energy calculations suggest ⁹Be extra neutron is held by 500KeV yet neutron energy admixed with ²¹⁰Po suggest a 1.2MeV barrier. Could the ⁹Be neutron tunnel to ¹⁰B ? ⁷Li has a low thermal neutron cross section (absorbs a neutron then rapidly decays to 2 alpha) yet fast neutrons give n + ⁷Li = 2 n + ⁶Li. Under high energy plasma conditions you discuss high temperatures and short contact times; read the description of the Muon catalyzed reaction and the higher contact time noted in the tunneling based processes. And particles only are mentioned yet X-rays can give ¹¹B* = ⁷Li + ⁴He and ⁷Li* = ⁴He + ³H.

²H + ⁶Li = 2 ⁴He

¹H + ¹¹B = 3 ⁴He

¹H + ³⁹K = ⁴⁰Ca as another aneutronic energy possibility?

Shjacks45 (talk) 13:56, 2 August 2011 (UTC)

Side reactions

See http://www.tpub.com/content/doe/h1019v1/css/h1019v1_108.htm Boron-11 plus alpha generates neutrons in neutron source. Shjacks45 (talk) 17:26, 5 August 2011 (UTC)

Deletion of vacuum cross section data

I object to this deletion because the statements about temperature are confusing when they are not stated in the energy cross sections. We should include the vacuum cross section. 75.166.192.187 (talk) 20:37, 5 July 2012 (UTC)

1. Why are you concerned about the local maximum at 2.6 MeV? It is several times lower than the absolute maximum at 550 keV. (See, e.g., Fig. 1.3 in http://fds.oup.com/www.oup.co.uk/pdf/0-19-856264-0.pdf)
2. What do you mean by using the peak "efficiently"? Why would low pressure be advantageous for that? What is your source for that statement?
3. Exactly which statements do you find confusing? (There is a detailed discussion of figures of merit in the Nuclear fusion article, especially in the intro to the Requirements section and the last three subsections of the Important reactions section. That might help reduce your confusion. If so, then we should probably link to it.)

Art Carlson (talk) 07:16, 6 July 2012 (UTC)

Let me read (1) so I can make sure I can answer (2) correctly. Then if there is confusion remaining I'll answer (3). Thank you for your help with this. 75.166.192.187 (talk) 21:16, 6 July 2012 (UTC)

(1) The shape of the peak is interesting. I don't know why I didn't see the larger cross section at 550 keV. I am still working on the other two. 71.212.249.178 (talk) 08:58, 8 July 2012 (UTC)

I removed that statement from the article again, pending the results of your research. Art Carlson (talk) 11:37, 2 September 2012 (UTC)

Merger proposal

I propose that the article Proton-boron fusion be merged into this article, Aneutronic fusion. Proton-boron fusion is a very small article already, and there is a lot of content overlap in this article. This article contains a lot of information about p –¹¹B fusion, while there is comparatively virtually nothing in the P-B fusion article. And, there is not a single link to Proton-boron fusion in this article, even though it talks about that a lot, so it seems like both articles have been developed separately. It would be better to merge the former into the latter. Llightex (talk) 09:06, 21 July 2014 (UTC)

• merge Riventree (talk) 02:29, 25 September 2014 (UTC)
• merge Seems logical to me. Martin Hogbin (talk) 07:33, 25 September 2014 (UTC)
• keep separate, the articles are both evolving and there is a long list of other candidate aneutronic reactions in this one. Since the candidate reaction is only a small part of the overall reactor, it seems there is enough to discuss regarding aneutronic infrastructure independent of each fusion reaction. — Preceding unsigned comment added by 24.224.172.34 (talk) 07:58, 8 March 2015 (UTC)

Since this was proposed over a year ago, I have not performed the merge, and placed the result into a separate chapter, with no further edits to speak of (to make it easier to follow the edit history). I'm sure it would be benefical with further cleanup. -- Egil (talk) 08:56, 15 December 2015 (UTC)

D+D?

Does the D+D reaction qualify for this article? The source below says it produces "no" neutrons...

https://www.sciencedaily.com/releases/2015/09/150925085550.htm

Lfstevens (talk) 02:42, 11 October 2016 (UTC)

Copyedit

I noticed that the article refers to this reaction:

¹¹B + α → ¹⁴N + n + 157 keV

I thought the reaction was

¹¹B + p

what's up? Lfstevens (talk) 16:27, 11 October 2016 (UTC)

cold fusion

https://newsroom.unsw.edu.au/news/science-tech/pioneering-technology-promises-unlimited-clean-and-safe-energy should be added to at least this article.

And why doesn't this article even mention LENR or even have a link to cold fusion, and why doesn't that article even mention boron-hydrogen fusion or even boron? --Espoo (talk) 15:02, 25 February 2020 (UTC)

Problem with protonic fusion.

High energy proton irradiation, in literature, seems less likely to fuse than to knock out a nucleon. (Thresholds for Fast Neutron Fission in Thorium and UraniumW. E. Shoupp and J. E. HillPhys. Rev. 75, 785 – Published 1 March 1949) Article uses proton irradiation of Lithium to generate neutrons. N14>p,n>C14 is generates Carbon14 on Earth. Be9>+n -2n>2He4 n>2MeV energy. We know tha 18% of neutrons absorbed by U235 become U236 and 82% fission. This wiki does not discuss the cross sections for proton absorption versus other reactions such as the p,n reaction or elastic collision. And no wiki article re proton absorption cross sections. TaylorLeem (talk) 16:50, 25 June 2020 (UTC)

Accelerator-based neutron source for boron neutron capture therapy-Yoshiaki Kiyanagi

Pretty high p to n conversion to be called "Aneutronic" - TaylorLeem (talk) 17:55, 25 June 2020 (UTC)

At http://tro.amegroups.com/article/view/4713/html&ved=2ahUKEwjr8OHmuZ3qAhXBs54KHeCbB0MQFjACegQIAhAB&usg=AOvVaw3QpIVDXYzl9nIC9kHf-v0u TaylorLeem (talk) 17:58, 25 June 2020 (UTC)

Unclear table under Reaction rates

The table in the Reaction rates subsection has a confusing right hand column. The section has no source to check with. The text says the column is cross-section (and the values could fit), but the column heading is <sigma.velocity>/T^2. Perhaps the values are the cross section, in which case the column heading should be explained, or the text is wrong and the column is somehow related to maybe the Lawson criteria. A source for the table, or the values in it, would be helpful. - Rod57 (talk) 12:36, 8 November 2020 (UTC)

Confusion regarding proton-Boron methods that employ two lasers

I am not an expert, but have read a bit about this topic today, and it seems to me that while the fusion reactions are the same, the way in which two lasers trigger fusion in the work by Cohen et al. (the paper in Nature) differs from the mechanism proposed by Hora et al. (and patented for the Australian company HB11). Am I right? Elias (talk) 19:30, 12 October 2021 (UTC)

High crossection?

If Li7 has a high cross section for p(,n) reaction then what about Li6 (p,n) = 2× He3? TaylorLeem (talk) 12:48, 8 December 2021 (UTC)