Talk:Inertial confinement fusion

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Contents 1 Barrel of Oil 2 NPOV 3 mr flibe 4 Removal of "pure fusion weapons" section 5 U of R 6 Definition of ICF 7 Requested Move

[edit] Barrel of Oil

" Theoretically, if the reaction completes with perfect efficiency (a practically impossible feat), a small amount of fuel about the size of a pinhead releases the energy equivalent to a barrel of oil.", Since when is a barrel of oil a unit of energy? This is just bad on so many levels, please reword. --PoorLeno 19:02, 12 January 2006 (UTC)

A barrel of oil is a standard unit of energy in the oil industry, corresponding to around 6GJ.

[1]

[2]

However, considering that most electricity is derived from fission and coal perhaps better units would be tonne of coal or kg of E.U. If you don't like, you reword. On what levels is it bad? njh 21:48, 12 January 2006 (UTC)

I guess you are right, but it felt very wrong the first time I read it. Obviously the BTU energy is derived from burning the said oil, though it still feels wrong to say that matter equals energy in a physics related article, and imply burning the matter... There are so many ways to extract energy from matter; it just seems unprofessional to automatically assume that everyone should understand what is meant from context. --PoorLeno 20:10, 13 January 2006 (UTC)

Ok, rewrite it in terms of kW hours or GJ or something. Then you can say, 'which is equivalent to burning a barrel of oil in a diesel generator'. I'm not sure how big a pin head is in anycase. njh 04:20, 14 January 2006 (UTC)

I changed it, but then the whole damn article just disappeared and I can't get it back by editing an older version!--Deglr6328 06:59, 14 January 2006 (UTC)

I really like the new version! --PoorLeno 19:41, 15 January 2006 (UTC)

[edit] NPOV

"If this is to be typical of the development of such systems, it is unlikely they will ever be a practical power source." - this comment sticks out in an otherwise excellent article as a piece of irrelevant opinion and should be deleted - Discuss! -Rich 00:37, 24 December 2005 (UTC)

I don't know, it smacks of unnecessary editorializing but I do completely agree with the statement itself. It's reasonable. Anyway, I would not revert if you removed it. --Deglr6328 02:55, 24 December 2005 (UTC)

The style is editorializing and I would like to see a source for the numbers. We have to know the original budget to know if it is now massively over budget., and it is important to know if the comparison is with an early estimate or the official budget at groundbreaking. Details belong in the article on the National Ignition Facility, which currently barely mentions the budget. I've sanitized it. --Art Carlson 09:43, 24 December 2005 (UTC)

And on that note, I have re-written the NIF article. It contains complete details. BTW Art, I personally consider "one order of magnitude" to be a very reasonable definition of "massively"! Maury 12:10, 13 September 2006 (UTC)

[edit] mr flibe

I thought flibe was LiF and BeF₂ rather than just generic salts. Does anyone know precisely? Should it be a new article, FLiBe?

flibe is just Li₂BeF₄ --Deglr6328 09:31, 31 December 2005 (UTC)

Molten_salt_reactor#The_molten_salt_reactor_experiment says that it is 2LiF-BeF₂. Is this different or merely a notational change? (I'm guessing that in a mixture of molten salts all the atoms are free anyway, so the two are identical, but when it solidifies perhaps they are different?)njh 23:22, 31 December 2005 (UTC)

[edit] Removal of "pure fusion weapons" section

I removed the section with the aforementioned title for the following reasons. 1- it is highly speculative at best, there is no accepted method by which a fusion weapon without a fission trigger could be built. it is thought to be impossible. 2- what is the connection between laser/ion/Z ICF research and pure fusion weapons?! there is little to none so far as I can see. 3- the section is a VERBATIM COPY of the "pure fusion weapon" article! redundancy on articles like this is not how wikipedia is intended to be built. just put a link.--Deglr6328 16:54, 17 July 2006 (UTC)

The material in that section was not an exact copy of the pure fusion weapons article (although some material should be merged). Note the different references, etc. Since there was actually a reference to a paper explaining how a pure fusion weapon might be possible (using current day technology), it seems unreasonable to just claim that fusion weapons are 'impossible' without any explanation. In fact, building an economical power station using ICF may actually be more difficult than building a deliverable weapon (the technical hurdles are different, of course).

The link between ICF and pure fusion weapons is that any pure fusion weapon would be inertially confined, would use similar fuel, etc (after all, the aim in ICF is to produce small fusion explosions). Quite a few people have thought seriously about how to weaponise ICF (and written articles about it). ICF research would be essential to the development of a pure fusion weapon: certainly ICF research has more relevance to developing new weapons than to weapons stewardship. So I think the link between ICF and pure fusion weapons is just as strong as to weapons stewardship or fusion power (even though ICF is not publically promoted as a path to new weapons). I have rewritten/removed some of the material from the end of the ICF and nuclear weapons section because it seemed a bit vague and unreferenced. I think that weaponization of ICF deserves some more writeup. Dashpool 07:25, 18 July 2006 (UTC)

ok maybe it wasn't verbatim but the only difference was the middle bit claiming that they are possible. I added that paragraph to the page. I would vey very much like to read that article, but who the heck has a copy of Science and Global security, Volume 7 p129-150? Anyway, I still seriously doubt the claim that it is possible to have a pure fusion weapon with anything near today's technology and would be willing to bet that the article lays out either some wildly exotic method for non fission triggered fusion or that it is an absurd extrapolation of pulsed elelectric power device miniaturization scheme. Arjun Makhijani has written several articles breathlessly worried about the possibility [3] but frankly I find the arguments contained within to be somewhat silly. His only (extremely remotely) plauseable suggestion for a possible pure fusion weapon seems to involve EPFCGs studied at Arzamas-16 which purportedly barely reached a yeild of 10^14n. That's at least a factor of 1-10 thousand away from just breakeven and probably (very roughly estimating) somewhere around a factor of a billion off of what would need to be achieved to do something like a Kt of tnt. So yeah, I just don't buy that its possible. However, Hans Bethe apparently thought that it was worrysome enough a prospect though that he actually warned the president not to pursue research in the area. But he was obvously badly shaken by previous experiences and such cautiousness is fully understandable. I just don't know where you would start with regard to edits linking ICF to pure fusion weapons research when there seems to be virtually no literature linking the subjects. --Deglr6328 08:05, 18 July 2006 (UTC)

May be you are not aware of all EPFCG devices designed in Russia, the EPFCG english article not being comprehensive. Have a look on fr:Générateur magnéto-explosif (if you can read French), or on this LANL document. Croquant 10:58, 18 July 2006 (UTC)

yes I have already read that document.--Deglr6328 20:55, 18 July 2006 (UTC)

This does bring up the question of why we do not already have a MTF article though.--Deglr6328 22:10, 18 July 2006 (UTC)

[edit] U of R

Why is there no reference to the University of Rochester's Laboratory for Laser Energetics? It jas the OMEGA laser system there, where they carry out tests now, not years from now when the NIF of ITER will be finished/started.

Perhaps because you haven't added it yet ;-)? Feel free to be bold and edit your information into the article!

Atlant 13:28, 15 August 2006 (UTC)

[edit] Definition of ICF

The article seems a bit inconsistent as to what constitutes ICF. The introduction defines ICF as involving lasers or heavy ion beams. Some of the article is written as though lasers are the only possible drivers, but there is a mention of Z-pinch and heavy ions as well. In the template an the bottom, 'Inertial confinement' has laser driven, z-pinch, and bubble fusion next to it. Does it only count as ICF if lasers or heavy ions are involved? Seems like Z-pinch driven hohlraums are very similar to laser driven hohlraums. And what about laser fast ignition of a fuel compressed by a Z-pinch? (Also, I second the idea that there should be an article on magnetised target fusion.) --Dashpool 12:10, 18 August 2006 (UTC)

I've tried to clean this up a bit. Maury 12:34, 13 September 2006 (UTC)

I don't think a heavy ion irradiation facility has ever even been built. all the papers I've ever seen are theoretical or are plans for facilities that were never pursued..... --Deglr6328 05:43, 9 October 2006 (UTC)

[edit] Requested Move

This article is entirely about lasers, while ignoring inertial electrostatic confinement (IEC) and acoustic inertial confinement (AICF). It should therefore be renamed to Laser inertial confinement fusion or similar. Actually, Laser fusion redirects here. It should be moved there. — Omegatron 15:04, 27 November 2006 (UTC)

No. The term "inertial confinement" is almost always used to refer to compression of pellets with beams, so this should remain the main article. I would like to see more on heavy ion beams, light ion beams, and electron beams here. We could put a note at the top mentioning IEC and bubble fusion, if we are worried about the occasional stray. --Art Carlson 16:13, 27 November 2006 (UTC)

Historical problem only. To date no-one's actually gone ahead and built a full-sized machine using anything other than lasers. Focusing was the primary concern. The recent move to indirect drive and hohlraums has changed things, however, and now there is some ongoing research into heavy ion beams again. In a couple of years "laser fusion" will no longer be appropriate. Maury 22:28, 27 November 2006 (UTC)

Beam confinement fusion, then. Look at our own navigation template. Magnetic and inertial confinement are the two large categories, within which are many specialized types. Acoustic, electrostatic, Z-pinch, and various types of beams are all types of inertial confinement with their own articles. Naming this article after the general category when it's only about beams is misleading. — Omegatron 22:42, 27 November 2006 (UTC)

The problem with that title is that it's a neologism. Searching Google for it gives me zero hits. - mako 00:03, 30 November 2006 (UTC)

No. The term ICF is not generally used to refer to IEC or AICF. Also, the physics of these is different enough that it would be out of place in this article. I agree that it is confusing that some techniques which utilise inertial confinement to produce fusion aren't classified here as 'ICF' but we have to stick with the established usage. I don't like Beam confinement fusion either: is a neologism and too restrictive. I think a slightly broader definition than Art suggested is appropriate: ICF is compression of pellets with pulsed energy sources (I rewrote it this way in the intro to include indirect drive and Z-pinch). It is also logical for this article to explain Z-pinches/ion beams/indirect drive because the physics is so similar. Even though direct laser compression is historically dominant, I think a wikipedia audience will be interested in a more broad discussion of the concept of ICF and the various promising techniques (these are emerging technologies, so competing approaches are worth considering). I'm not sure what a 'full size' machine is but the Z machine looks pretty big to me.--Dashpool 15:11, 30 November 2006 (UTC)

Inertial confinement fusion (beams), then. I'm sure one of you can come up with a name that is accurate, sticks with established usage, and isn't misleading, but no one is trying. — Omegatron 14:29, 12 December 2006 (UTC)

If somebody types in "inertial confinement fusion" then this is probably the article they want to see. If the name is changed, then I would plead for a REDIRECT from [[inertial confinement fusion]] to [[Inertial confinement fusion (beams)]], so what's the point? --Art Carlson 15:35, 12 December 2006 (UTC)