Cold fusion

[UncleAl]

Pons and Fleishman; old as the hills; beaten to death by the Japanese amongst others. In short, deuterium nuclei were to closely approach and fuse by quantum tunneling, their charge repulsion compensated by the palladium lattice. MeV nuclear events were to be modulated by eV chemical events.

In practice, the thing is totally irreproducible if it does anything at all. No radiation release and no fusion products are validly detected in any case. Absent LiOH electrolyte, nothing at all happens aside from the occasional explosion of D2/O2. Exotherms are caused by an Li-rich Li/Pd rind violently alloying with bulk Pd. Li/Pd braze alloys are common. Li dissolving in Pd outputs a purely amazing amount of heat plus a mjaor depression in melting point, alloy vs. Pd metal. Sodium dissolving in mercury also has a huge exotherm - enough to boil the mercury even at low Na final concentrations.

[Qfwfq]

Originally Posted by UncleAl

Pons and Fleishman

That's what those names were! I couldn't remember them. They made the bogus claim that got so much more resonance than mu catalysis, which is on perfectly reasonable grounds.

[BlameTheEx]

I posted on this topic before here:

Cold Fusion comes back from the cold.

The gist of my post was a link to this article which suggests that Cold Fusion may not be quite the "Junk Science" we have all assumed:

http://www.spectrum.ieee.org/WEBONLY.../0904nfus.html

There is a very short article here which suggests to me a possible mechanism. Could collapsing bubbles provide the necessary temperature and pressure?:

http://www.eurekalert.org/pub_releas...-tic022805.php

[Qfwfq]

Your second link talks of temperature four times that of the sun's surface and presumeably more inside. The temperature in the centre of the sun is far greater than at the surface. I'm a bit skeptical about a collapsing bubble being sufficient for causing fusion.

Actually, 20,000 Kelvin is a little over three times the surface of the sun and anyway I'm a bit doubtful of it being reached in the collapsing bubble.

[BlameTheEx]

Qfwfq

Doubt all you want. It can't be concidered better than a long shot - but it is valid science.
More links here:

http://www.physicstoday.org/vol-55/iss-4/p16.html
http://www.nature.com/news/2005/0502...0228-7_pf.html

[Qfwfq]

I don't rule out that a tiny amount of plasma may form in a collapsing bubble but 15 or 20 thousand K isn't nearly enough to cause fusion, afaik.

Originally Posted by BlameTheEx

but it is valid science.

What do you mean by "valid science"? Some of the things these articles say don't seem to match up. In particular, I smiled at the notion that "only in a plasma" could an oxygen molecule become ionized without breaking up.

In any case, considering the way they induce the phenomenon, I think we'll be waiting a while before we see a breakeven.

Wouldn't it make more sense, to research purposes, for them to take a saturated solution of deuterium in pure heavy water and see if any helium was produced?

[BlameTheEx]

I would call it valid science because valid scientists are co-operating in research on this and publishing results. There is apparently theoretical reason to believe that bubble fusion is possible. Only possible mind you, not probable or certain. Given the benefits of success that is good enough reason for scientists to research the matter.

Sadly I am not an expert on bubbles collapse to tell you if heavy water would have been a better bet.

[Qfwfq]

Originally Posted by BlameTheEx

Only possible mind you, not probable or certain.

I can agree with that but I am wary of loose expressions such as "valid science" that have an ample semantic range.

Originally Posted by BlameTheEx

Sadly I am not an expert on bubbles collapse to tell you if heavy water would have been a better bet.

I'm not an expert on bubble collapse either but I can tell you that, if one wants to investigate the chances of employing the effect for fusion, what I said would be a perfectly logical step and perhaps in parallel with measurements on other fluid compositions.

I queried friends of mine that are more expert on fusion and one of them is still doing tokamak research in a national lab over here, but she is at Cadarache (http://www-cad.cea.fr/) for a few days. The guy that did reply grants that order could be a significant factor as well as temperature. Ordinarily a plasma temperature of 100 million kelvin is necessary.

I still tend to think the bubble effect is even less likely to reach a breakeven than with the muon catalysis effect.

[Qfwfq]

I received my friend's reply from Cadarache, I'll just say the jist of it in English. She says that she hadn't heard of this but Oak Ridge is the lab Ralph Isler comes from, not that this rules out there being the odd jerk there, but she esteems that lab. Isler was one of her superiors when she was working in California, after a fire at the lab in Padova where she is again working. She also says the full criteron is the product of temperature, density and confinement time being sufficient. Thus inertial confinement requires higher density to make up for briefer time. Of course an even higher density could also make up for lower temperature.

This is what she said, I would remark that a temperature less than a thousandth of that in a tokamak, as well as the briefer time of inertial confinement, would sure require a huge density!!! IMHO, even if they can cause fusion I doubt they'll get a breakeven more easily than with laser confinement or other methods.

[paultrr]

While I have not studied the whole cold fusion issue enough to answer much I have wondered if its possible the bubble effect is not related to the Casmir effect. In essence the bubble boundry in liquid forms its own shrinking conductive wall of sorts. If one considered lower internal quantum energy states than external the question might be asked would the signature of fusion and the thermo signature of such be the same as one normally would expect?