Details to be explained or addressed

I'm starting to get a sense of what I think might be going on in the LENR experiments.  The idea is that there's a photoelectric effect involving a gamma or an X-ray and an electron, which gives rise to a bosonic quasiparticle which can then combine with a free proton in the metal lattice and yield a neutron. An earlier post has already noted some difficulties in adopting an explanation that involves neutrons.

In addition, there are other details which may not seem contradictory to an account involving neutrons but which nonetheless need to be explained or addressed.  Edmond Storms mentions some of these details in his excellent paper, "A Student's Guide to Cold Fusion." For a Pd/D electrolysis experiment, these details include (possible explanations in parentheses):

• Lack of correlation between neutron detection and heat (neutrons were absorbed during heat generation and so could not be detected).
• Far too few gammas for generated heat, lack of correlation (gammas are also absorbed in the reaction).
• X-rays are not always detected in proportion to generated heat.
• High Pd/D average loading is usually required (high loading is a proxy for the flux of free protons through the nuclear-active environment).
• High Pd/D average loading is not always required (there are sufficient free protons in the nuclear active environment, despite the low loading).
• Current must be maintained for a sufficient amount of time, but this time can be short for thin layers of palladium and a long time for bulk palladium (there has to be 1, sufficient proton flux, and 2, an energetic photon that comes along for some reason to set off the reaction).
• Impurities can activate inactive palladium (the palladium is not what is involved in the reaction; it is a catalyzer).
• Success in getting a reaction depends upon the batch of palladium (there has to be something that gives rise to the right optical phenomena, e.g., microcavities).
• H2O contamination will stop a reaction (the atomic hydrogen does not ionize and prevents the deuterium from entering the lattice).
• A higher temperature causes the reaction to go more quickly.

There are details in other types of experiments that need to be addressed as well:

• There is an effective positive charge for hydrogen migrating through palladium in some electrodiffusion experiments (I have speculated elsewhere that it is atomic hydrogen and not ions that migrate).
• Energy and nuclear products have been seen when >1 MHz sonic waves are used to react deuterium with solid metals.

Challenges for neutron production

Any explanation for cold fusion that involves neutrons will run into a number of objections.  Edmond Storms sets out several of these objections in section 8.2.1 of his invaluable book, The Science of Low Energy Nuclear Reaction.  (I highly recommend this book to anyone exploring cold fusion.)  In that section there is a numbered list of considerations, and considerations 2 and 4 seem to involve in part a lack of observed beta particle emission.  I wrote Dr Storms and asked him about these two considerations, specifically, and the basis for concluding that beta particle emission is missing.  I wondered whether this conclusion was based on the CR-39 evidence, which involves detecting tracks left in a kind of plastic that is used in sunglasses.  This plastic is typically inserted directly into the electrolyte.  A method of detection along these lines is necessary because beta particles cannot pass through the walls of the closed systems that are used in the cold fusion experiments.

In his helpful reply, Dr Storms seemed to indicate that these considerations were getting at something else in addition to the lack of beta particle emission.  Here is the gist of what he said:

1. Occasionally neutrons are seen, but their levels are very low and their source unknown and unrelated to heat production.
2. The radioactivity expected when neutrons interact with their surroundings is easy to detect using a cheap Geiger-Muller counter and has been sought and rarely seen.
3. Neutrons are short-lived, with a half-life of ~ 16 minutes, so they must be constantly replenished in a sustained reaction.  This is not possible in ordinary materials.

Storms' points have obviously been given some thought, and I hope to learn more about each of them.  I understand that he discusses the low levels of neutrons that are occasionally seen in his "Student's Guide" and offers a possible explanation, so I will read that paper first before drawing any conclusions in the present connection.

Ionization of hydrogen isotopes

I'm redacting an email I sent to vortex-l and putting it up here, since the list appears to be down.

In a recent thread on vortex-l, Axil mentioned that tungsten has a low hydrogen permeability and that this causes problems for Brillouin's and Widom and Larsen's hypotheses. He provided some interesting links, and he appears to be correct about the permeability of hydrogen-1 in tungsten.

I find the low hydrogen-1 permeability an encouraging result, for roundabout reasons. A conjecture that I think we should consider is that ionization of the hydrogen isotope (hydrogen-1, hydrogen-2, etc.) is a requirement for a cold fusion reaction to proceed. One of the questions that has been bugging me is why hydrogen-1 appears to work well with nickel but palladium seems to require deuterium, and hydrogen-1, if anything, seems to interfere. This could be an overstatement; there have been many experiments, and I wouldn't be surprised if there is some countervailing evidence, but this seems to be the general trend of what is being seen, as far as I can tell.

The low hydrogen-1 permeability of tungsten lends credence to the notion that the size of the lattice (and, apparently, it's Miller number -- 100, 110, etc.) is a factor here. So we might guess that palladium allows for the diffusion of monoatomic hydrogen, but it does not yield high levels of hydrogen ions, whereas nickel perhaps does. The following link is suggestive concerning the migration of monoatomic hydrogen (rather than unshielded protons) in palladium:

http://pureguard.net/cm/Library/Palladium_Membrane_Purification.html

Like others, I think the heat-after-death effect, where a reaction continues after the current has been stopped, is not central to what is going on, so I see no strict need to require diffusion of hydrogen in the bulk of the cathode. Indeed, there is evidence that what is going on is a surface or near-surface reaction; the low permeability of hydrogen in tungsten seems to point in this direction as well. There is the question of the need for high loading in Pd/D electrolytic systems to see an effect; one possible explanation here is that you just need a high enough concentration of free deuterons on (or near) the surface of the cathode to see results in a situation in which we barely control the reaction, and high loading gives rise to this as a side effect, due to the desorption over time of large numbers of deuterons.

Ionization is also something that would happen in the glow discharge and electric arc experiments.

What role might ionization play? To pursue my pet hypothesis, perhaps you need an unshielded proton or deuteron in order for something to happen in connection with the its electrostatic charge. If bulk loading only plays an indirect role in specific systems and it was not needed in previous tungsten experiments because, for example, sufficient ionization was brought about through other means, it's not clear what the implications are for Brillouin's, Widom and Larsen's, or for that matter, Peter Hagelstein's hypotheses.

Optical microcavities and a possible photoelectric effect

One possibility that I'm entertaining is that cold fusion is a photoelectric effect, operating at X-ray or gamma energies.  There are some interesting correlations in this connection.  The basic idea is that the cathode has cavities in which photons resonate, in turn triggering an unknown process.  There are cavities and structures on cathodes on the order of hundreds of nanometers that have been observed using scanning electron microscopes.

An interesting review paper in Nature titled "Optical microcavities" (2003) discusses a number of developments in exploring optical microcavities.  A typical cavity is several micrometers across.  These microcavities have a parameter Q, which is a measure of the resonance quality.  The higher the Q, the less likely photons are to dissipate.  A high Q permits strong coupling to take place.  Strong coupling implies a coupling constant g that is around or larger than 1.  When it occurs, you can get a phenomenon in which an atom in an exited state emits a photon which transfers to a "cavity mode" and then eventually is reabsorbed by the atom many times, an effect called the Rabi cycle.  With a g << 1, there will be weak coupling, which will lead to the photon being dissipated too quickly to see such an effect.  Some of the experiments exhibit a Q ~ 13,000, which is very high.  Also, systems in which strong coupling takes place must be modeled using non-perturbative methods.  One possible implication is that such systems are less well-understood by physicists, who are unable to rely on perturbation theory, a basic tool in quantum mechanics.

Is it even possible for a gamma or an X-ray to resonate in a cavity on the scale of hundreds of nanometers?  If not, what are the wavelengths associated with the cavity modes for cavities on this scale?

Possible errors in the evidence of transmutations

Abd ul-Rahman was kind enough to provide this reference for further reading on possible errors in Iwamura's experiments:

• "Journal of Condensed Matter Nuclear Science," vol. 6, Feb. 2012, http://iscmns.org/CMNS/JCMNS-Vol6.pdf

Evidence on the transmutation of heavy elements

I've reactivated this blog after a hiatus of several months.  At some point sometime back I joined the vortex-l mailing list.  This is perhaps the best place to find the latest news and commentary on what's going on with cold fusion.  I still have quite a bit to learn about the basic science involved in LENR.  Sometimes, however, I like to jump into a technical thread, which I invariably seem to turn into a philosophical discussion; for example, there was this exchange today:

The present mode of academic research, of excluding from consideration anything that has not been entered into the official record, is only suitable for legal courts and the obtaining of tenure.  It's not the most efficient way of getting at the truth by any means, and as I become more and more familiar with academic research, I'm grateful not to feel bound by it.

Also, over the weekend, I somehow felt confident enough to offer the outlines of my own theory about what is going on with LENR, which proceeds from a recent article in Science that discusses a new quasi-particle that is created from a photon and an electron.  The basic idea is this:  when hydrogen atoms are drawn into the nickel lattice, the electrons and protons are dissociated, and the electrons enter into the free moving electrons of the metal.  Then comes along a high energy photon, which combines with one of the electrons, creating the new quasi-particle, a so-called "dipolariton."  The new particle is a boson rather than a fermion and is a static dipole, apparently meaning it has a positive and a negative charge.  I would imagine that the negative side is instantly attracted to a nearby proton, and because the two are not both fermions, they readily combine, yielding a high energy photon and a slow neutron.  The photon bounces around a cavity in the metal lattice until it combines with another electron, starting the process anew.

The slow neutrons react primarily with impurities in the lattice.  I'm guessing that any palladium atoms that it encounters quickly re-emit it.  For reasons that have yet to be worked out, the reaction only takes place between free protons and free electrons, so you have to have a flux of hydrogen, which agrees with the evidence.

I'll need to look into the possible Pd-104(n,*) reactions and what their half-lives are.  I also need to better understand Fermi-Dirac statistics, Einstein-Bose statistics, the possible interactions between fermions and bosons.

In the exchange above, with a fellow by the name of Abd ul-Rahman, who is quite knowledgeable about particle physics, he presented additional details on Peter Hagelstein's latest thinking as well as an experiment that is being prepared for publication.  He primarily took issue with the specifics of Widom and Larsen's theory, while I was concerned solely with neutron flux as a general phenomenon, and to a certain extent I think we ended up speaking past one another.  But he mentioned that there are questions about reliability of the evidence on transmutations, and I need to better understand these issues.  What he mentioned about Peter Hagelstein's work with lasers also squares well with my dipolariton explanation, although he's looking at a Bose-Einstein condensate of deuterons and at specific laser frequencies, and I don't have any opinion on these things yet.

Here are some links to further reading that came up during the thread:

• "About the possibility of decreased radioactivity of heavy nuclei," http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=512913
• "Cold Fusion and Decrease of Tritium Radioactivity," http://www.lenr-canr.org/acrobat/Reifenschwcoldfusion.pdf
• "Reduced radioactivity of tritium in small titanium particles," http://www.lenr-canr.org/acrobat/Reifenschwreducedrad.pdf
• "Debate Between Douglas Morrison and Stanley Pons & Martin Fleischmann," http://lenr-canr.org/acrobat/Fleischmanreplytothe.pdf
• "Robert Godes of Brillouin Energy Comments on LENR Research," http://www.e-catworld.com/2012/04/robert-godes-of-brillouin-energy-comments-on-lenr-research/
• "Carbon nanotubes: The weird world of 'remote Joule heating,'" http://phys.org/news/2012-04-carbon-nanotubes-weird-world-remote.html
• "10th International Workshop on Anomalies in Hydrogen Loaded Metals" (abstracts), http://www.iscmns.org/work10/Abstracts.pdf