Known mechanisms that increase nuclear fusion rates in the solid state - Metzler et al. - August 2022

  • Quote

    We investigate known mechanisms for enhancing nuclear fusion rates at ambient temperatures and pressures in solid-state environments. In deuterium fusion, on which the paper is focused, an enhancement of >40 orders of magnitude would be needed to achieve observable fusion. We find that mechanisms for fusion rate enhancement up to 30 orders of magnitude each are known across the domains of atomic physics, nuclear physics, and quantum dynamics. Cascading such mechanisms could lead to an overall enhancement of 40 orders of magnitude and more. We present a roadmap with examples of how hypothesis-driven research could be conducted in—and across—each domain to probe the plausibility of technologically-relevant fusion in the solid state.

    Known mechanisms that increase nuclear fusion rates in the solid state
    We investigate known mechanisms for enhancing nuclear fusion rates at ambient temperatures and pressures in solid-state environments. In deuterium fusion, on…
    arxiv.org


    Well worth everybody's time.

  • This paper is totally consistent with the general tone of the presentation given by Metzler at the ICCF24 and with the idea of Solid State Fusion that was embraced by the ICCF 24 organizing committee, to bring LENR to a level of being an alternative approach to hot fusion research. I have nothing against this approach, it’s very helpful to bring funding opportunities for research.


    My concerns on this approach are more on the side that this is still viewing the phenomena as something explainable by classic approaches and theories but only poorly understood or overlooked so far. I personally think that taking that approach is a dead end.

    I certainly Hope to see LENR helping humans to blossom, and I'm here to help it happen.

  • This is probably what Sabine read or discussed with Florian Metzler before doing the script for her video.

    Transcript from Sabine's CF video. She has some very positive things to say about LENR, especially towards the end:


    Cold fusion could save the world. It’d be a basically unlimited, clean, source of energy. It sounds great. There’s just one problem: it’s not working. Indeed, most physicists think it can’t work even in theory. And yet, the research is making a comeback. So, what’s going on? What do we know about cold fusion? Is it the real deal, or is it pseudoscience? What’s cold fusion to begin with? That’s what we’ll talk about today.If you push two small atomic nuclei together, they will form a heavier one. This nuclear fusion releases an enormous amount of energy. There’s just one problem: Atomic nuclei all have a positive electric charge, so they repel each other. And they do so very strongly. The closer they are, the stronger the repulsion. It’s called the Coulomb barrier, and it prevents fusion until you get the nuclei so close together that the strong nuclear force takes over. Then the nuclei merge, and boom.

    The sun does nuclear fusion with its enormous gravitational pressure. On earth, we can do it by heating a soup of nuclei to enormous temperatures, or by slamming the nuclei into each other with lasers. This is called “hot nuclear fusion”. And that indeed works. There’s just one problem: At least so, far hot fusion eats up more energy than it releases. We talked about the problems with hot nuclear fusion in this earlier video.
    But nuclear fusion is possible at far lower energy, and then it’s called cold fusion. The reason this works is that atomic nuclei don’t normally float around alone but have electrons sitting in shells around the nucleus. These electrons shield the positive charges of the nuclei from each other and that makes it easier for the nuclei to approach each other.

    There’s just one problem: If the atoms float around freely, the electron shells are really large compared to the size of the nucleus. If you bring these nuclei close together, then their electron shells will be much farther apart than the nuclei. So the electron shells don’t help with the fusion if the nuclei just float around.
    One thing you can do is strip off the electrons and replace them with muons. Muons are basically heavier versions of electrons, and since they are heavier, their shells are closer to the nucleus. This shields the electric fields of the nuclei better from each other and makes nuclear fusion easier. It’s called “muon catalyzed fusion”.
    Muon catalyzed fusion was theoretically predicted already in the 1940s and successfully done in experiments in the 1950s. It’s cold fusion that actually works. There’s just one problem: muons are unstable. They must be produced with particle accelerators and those take up a lot of energy. The muons then get mostly lost in the first fusion reaction so you can’t reuse them. There’s a lot more to say about muon catalyzed fusion, but we’ll save this for another time.
    There’s another type of “cold fusion” that we know works, which is actually a method for neutron production. For this you send a beam of deuterium ions into a metal, for example titanium. Deuterium is a heavy isotope of hydrogen. Its nucleus is a proton with one neutron. At first, the beam just deposits a lot of deuterium in the metal. But when the metal is full of deuterium, some of those nuclei fuse. These devices can be pretty small. The piece of metal where the fusion happens may just be a few millimeters in size. Here is an example of such a device from Sandia Labs which they call the “neutristor”.
    The major reason scientists do this is because the fusion releases neutrons, and they want the neutrons. It’s not just because lab life is lonely, and neutrons are better than no company. Neutrons can also be used for treating materials to make them more durable, or for making radioactive waste decay faster.
    But the production of the neutrons is quite an amazing process. Because the beam of deuterium ions which you send into this metal typically has an energy of only 5-20 kilo electron Volt. But the neutrons you get out, have almost a thousand times more energy, in the range of a few Mega electron Volt. It’s often called “beam-target fusion” or “solid-state fusion”. It’s a type of cold fusion, and again we know it works.
    There’s just one problem: The yield of this method is really, really low. It’s only about one in a million deuterium nuclei that fuse, and the total energy you get out is far less than what you put in with the beam. So, it’s a good method to produce neutrons, but it won’t save the world.
    However, when physicists studied this process of neutron production, they made a surprising discovery. When you lower the energy of the incoming particles, the fusion rates are higher than theoretically expected. Why is that? The currently accepted explanation is that the lattice of the metal helps shielding the charges of the deuterium nuclei from each other. So, it lowers the Coulomb barrier, and that makes it more likely that the nuclei fuse when they’re inside the metal. This isn’t news, physicists have known about this since the 1980s.
    But if putting the deuterium into metal reduces the Coulomb barrier, maybe we can find some material in which it’s lowered even further? Maybe we can lower it so far that we create energy with it? This idea had been brought up already in the 1920s by researchers in the US and Germany. And it’s what Pons and Fleischman claimed to have achieved in their experiment that made headlines in 1989.
    Pons and Fleischman used a metal called palladium. The metal was inside a tank of heavy water, so that’s water where the normal hydrogen is replaced with deuterium. Ponds and Fleischman then applied a current going through the palladium and the heavy water. They claimed this created excess heat, so more than what you’d get from the current alone. They also said they’d seen some decay products of fusion reactions, notably neutrons and tritium. Everyone was very excited.
    There was just one problem... Other laboratories were unable to reproduce the claims. It probably didn’t help that Pons and Fleischmann were both chemists, but nuclear fusion has traditionally been territory of physicists. And physicists largely think that chemical reactions simply cannot cause nuclear fusion because the typical energies that are involved in chemical processes are far too low.
    A few groups said they’d seen something similar to Ponds and Fleischman, but the findings were inconsistent, and it remained unclear why it would sometimes work and sometimes not. By the early nineties, the Pons and Fleischmann claim was largely considered debunked. Soon enough, no scientist wanted to touch cold fusion because they were afraid it would damage their reputation. The philosopher Huw Price calls it the “reputation trap”. In fact, while I was working on this video, I’ve been warned that I, too, would be damaging my reputation.
    Of course not everyone just stopped working on cold fusion. After all, it might save the world! Some carried on, and a few tried to capitalize on the hope.
    One such case is that of Andrea Rossi who already in the 1970s said he knew how to build a cold fusion device. In 1998, the Italian government shut down his company on charges of tax fraud and dumping toxic waste into the environment. In the mid 1990s, Rossi moved to the USA and by 2011, he claimed to have a working cold fusion device that produced excess heat.
    He tried to patent it, but the international patent office rejected the application arguing that the device goes “against the generally accepted laws of physics and established theories”. A rich Australian guy offered $1 million to Rossi if he could prove that the device produces net power. Rossi didn’t take up the offer and that’s the last we heard from him. There’s more than one problem with that.
    In 2019, Google did a research project on cold fusion and they found that the observed fusion rate was 100 times higher than theoretically expected. But it wasn’t enough to create excess heat.
    The allure of cold fusion hasn’t entirely gone away. For example, there are two companies in Japan, Technova Inc. and Clean Planet Inc, which claim to have produced excess heat. Clean Planet Inc has a very impressive roadmap on their website, according to which they’ll complete a model reactor for commercial application next year. There’s just one problem: No one has seen the world-saving machine, and no one has reproduced the results.
    The people who still work on cold fusion have renamed it to “Low Energy Nuclear Reactions”, LENR for short. Part of the reason is that “cold” isn’t particularly descriptive. I mean, these devices may be cold compared to the interior of the sun, but they can heat up to some hundred degrees Celsius, and maybe that’s not everybody’s idea of cold. But no doubt the major reason for the rebranding is to get out of the reputation trap. So make no mistake, LENR is cold fusion reborn.
    I admit that this doesn’t sound particularly convincing. But I think it’s worth looking a little closer at the details. First of all, there are two separate measurements that cold fusion folks usually look at. That’s the production of decay products from the nuclear fusion, and the production of excess heat.
    An experiment that tried to shed light on what might be going on comes from a 2010 paper by a group in the United States. They used a setup very similar to that from Fleischmann and Pons but in addition they directed a pulsed laser at the palladium with specific frequencies. They claimed to see excess power generation for specific pulse frequencies, which suggests that phonon excitations have something to do with it. There’s just one problem: a follow-up experiment failed to replicate the result.
    Edmund Storms who has been working on this for decades published a paper in 2016 claiming to have measured excess heat in a device that’s very similar to the original Ponds and Fleischman setup. In this figure you see how the deuterium builds up in the palladium, that’s the red dots, and the amount of power that Storms says he measured.
    He claims that the reason that these experiments are difficult to reproduce is that the nuclear reactions happen in appreciable rates only in some regions of the palladium which have specific defects that he calls nano-cracks. These could be caused by the treatment of the metal, so some samples have them and others not, and this is why the experiments sometimes seem to work and sometimes not. At least according to Storms. There’s just one problem: No one’s been able to replicate his findings.

    There is also a 2020 paper from the Japanese company, Clean Planet Inc which I already mentioned. They use a somewhat different setup with nanoparticles of certain metals that are surrounded by a gas that contains deuterium. The whole thing is put under pressure and heated. They claim that the resulting temperature increase is higher than you’d expect and that their device generates net power. In this figure you see the measured temperature increase in their experiment with Helium gas and with a gas that contains deuterium. The Helium gas serves as a control. As you see there’s more heating with the deuterium. There’s just one problem: No one’s been able to replicate this finding.
    The issue with these heat measurements is that they’re incredibly difficult to verify. For this reason it’s much better to look at the decay products. Those are in and by themselves mysterious. In a typical nuclear fusion reaction, there is a very specific amount of energy that’s released, and so the energy distribution of the decay products is very sharply peaked. In deuterium fusion, the neutrons in particular should have an energy of 2.45 MeV. In those cold fusion reactions, however, they see a fairly broad distribution of neutron energies and at higher energies than expected.
    Here is an example. The red bars show the number of deuterium ions as a function of energy, the black ones are the background. As you can see the spectrum looks nowhere like the expected peak at about 2.5 MeV. Something is going on and we don’t know what. Forget saving the world for a moment, it’s much simpler, there’s an observation that we don’t understand.
    In a recent paper, a group from MIT has put forward two different hypotheses that could explain why nuclear fusion happens more readily in certain metals than you’d naively assume. One is that there are some unknown nuclear resonances which can become excited and make fusion easier. The other one is that the lattice of the metal facilitates an energy transfer from the deuterium to some of the palladium nuclei. So then you have excited Palladium nuclei and those decay. Since the Palladium nuclei have more decay channels than are typical for fusion outputs, this can explain why the energy distribution looks so weird. There’s just one problem: We don’t know that that’s actually correct.
    What are we to make of this? The major reason cold fusion has been discarded as pseudoscience is that most physicist think it can’t possibly be that chemical processes cause nuclear reactions. But I think they overestimate how much we know both about nuclear physics and chemistry.
    Nuclear physics is dominated by the strong nuclear force which holds quarks and gluons together so that they form neutrons and protons. The strong nuclear force has the peculiar property that it becomes weaker at high energies. This is called asymptotic freedom. Arvin Ash recently did a great video about the strong nuclear force, so check this out for more details.
    The Large Hadron Collider pumps a lot of energy into proton collisions. This is why understanding the strong nuclear force in LHC collisions is quite simple, by which I mean a PhD in particle physics will do. The difficult part comes after the collisions, when the quarks and gluons recombine to protons, neutrons, and other bound states such as pions and rhos and so on. It’s called hadronization, and physicists don’t know how to calculate this. They just extract the properties of these processes from data and parameterize it.
    I am telling you this to illustrate that just because we understand the properties of the constituents of atomic nuclei doesn’t mean we understand atoms. We can’t even calculate how quarks and gluons hold together.
    Another big gap in our understanding are material properties because we often can’t calculate electron bands. That’s especially true for materials with irregularities that, according to Storms, are relevant for cold fusion. Indeed, if you remember, calculating material properties is one of those questions that physicists want to put on a quantum computer exactly because we can’t currently do the calculation. So, is it possible that there is something going on with the nuclei or electron bands in those metals that we haven’t yet figured out? I think that’s totally possible.
    But, let me honest, I find it somewhat suspicious that the power production in cold fusion experiments always just so happens to be very close to the power that goes in. I mean, there isn’t a priori any reason why this should be the case. If there is nuclear fusion going on efficiently, why doesn’t it just blow up the lab and settle the case once and for all?
    So, well, I am extremely skeptical that we’ll see a working cold fusion device in the next couple of years. But it seems to me there’s quite convincing evidence that something odd is going on in these devices that deserves further study.
    I’m not the only one who thinks so. In the past couple of years, research into cold fusion has received a big funding boost, and that’s already showing results. For example, in 1991, a small group of researchers proposed a method to produce palladium samples that generate excess heat more reliably. And, I hope you’re sitting, research groups at NASA and at the US Navy have recently been able to reproduce those results.
    A project at the University of Michigan is trying to reproduce the findings by the Japanese companies. The Department of Energy in the United States just put out a call for research projects on low energy nuclear reactions, and also the European research council has been caught in the act of supporting some cold fusion projects.
    I think this is a good development. Cold fusion experiments are small and relatively inexpensive and given the enormous potential, it’s worth the investment. It’s a topic that we’ll certainly talk about again, so if you want to stay up to date, don’t forget to subscribe. Many thanks to Florian Metzler for helping with this video.

  • Shane D. , I may have sounded like I think that Sabine’s video was negative. I think she was being playful, and jocular, not taking things much seriously, as she usually does, but she at the end recognized that the field has value and should be pursued, albeit she suggested we are not even close to make it useful yet.


    She indeed has been negative to hot fusion, on the other hand.

    I certainly Hope to see LENR helping humans to blossom, and I'm here to help it happen.

  • Transcript from Sabine's CF video.

    That must have been a lot of work! Did you use some sort of voice input program? Ruby has been experimenting with one.

    She has some very positive things to say about LENR, especially towards the end:

    I guess overall it was good, but her snarks were annoying. The title is "there's just one problem" and the one problem is: this and that have not been replicated. She is wrong. Some of those things have been replicated. No one has even tried to replicate the others. So that tells you nothing about cold fusion. She should have said, "no one has tried to replicate these things yet, so we don't know if they are true."


    People will get the impression that researchers tried to replicate, and failed, which means the claims are probably wrong. She emphasizes that apparent failure in the title, for goodness sake. That's a big distortion.

  • She is wrong. Some of those things have been replicated. No one has even tried to replicate the others. So that tells you nothing about cold fusion. She should have said, "no one has tried to replicate these things yet, so we don't know if they are true."

    That's exactly why I told her on the comments that she had 33 years of research to catch up with.

    I certainly Hope to see LENR helping humans to blossom, and I'm here to help it happen.

  • My concerns on this approach are more on the side that this is still viewing the phenomena as something explainable by classic approaches and theories but only poorly understood or overlooked so far. I personally think that taking that approach is a dead end.

    Perhaps it's wrongheaded of me, but almost irrespective of whether Metzler is ultimately proved correct, it seems reasonable to suggest that this paper is valuable from a sociological perspective, in that it provides a plausible theoretical bridge to LENR that might be valuable in a 'rhetorical' sense.


    It seems like the kind of paper that could help move a stubborn professor towards begrudgingly accepting the possibility of LENR; or the kind of paper that a young student could counter charges of quackery with. Said differently, it's an elegant and persuasive statement of the possibility of LENR, made in terms that are uncontroversial and palatable, and that seems like a valuable thing in and of itself.

  • Again, this paper is very great expecting some nucleon resonances INSIDE the nucleus.

    In relation with Wyttenbach way of understanding we can read below:


    From page 4:

    ; ii) the strong nuclear force is strongly attractive at 1 fm < 2 fm, yet strongly repulsive at <1 fm, and; iii) the strong nuclear force is not organized around a center. Classical computers cannot easily handle these challenges65. Accordingly, our understanding of intranuclear resonances is presently limited to what is experimentally accessible.

  • Again, this paper is very great expecting some nucleon resonances INSIDE the nucleus.

    In relation with Wyttenbach way of understanding we can read below:


    From page 4:

    ; ii) the strong nuclear force is strongly attractive at 1 fm < 2 fm, yet strongly repulsive at <1 fm, and; iii) the strong nuclear force is not organized around a center. Classical computers cannot easily handle these challenges65. Accordingly, our understanding of intranuclear resonances is presently limited to what is experimentally accessible.

    And luckily, the people doing it will be using the mainstream stuff (quark model etc) which whether you like the theory or not is fully backed by experimental results.


    Resonances inside the nucleus, and energy levels of it, have been known for a long time and while the QCD is not easily soluble we have made progress theoretically as well as experimentally:


    (20 years old)

    Some aspects of resonances in nuclear physics are discussed. Their properties are studied and it is shown how to obtain them numerically in realistic situations for experimental detection. Particular attention is given to resonances in non-spherical potentials that represent deformed exotic nuclei, and their trajectories in the complex energy plane are followed.

    Resonances in nuclear physics
    Some aspects of resonances in nuclear physics are discussed. Their properties are studied and it is shown how to obtain them numerically in realistic …
    www.sciencedirect.com


    (5 years ago)

    https://arxiv.org/abs/1507.06622We present the first ab initio calculation of a radiative transition of a hadronic resonance within quantum chromodynamics (QCD). We compute the amplitude for πππγ, as a function of the energy of the ππ pair and the virtuality of the photon, in the kinematic regime where ππ couples strongly to the unstable ρ resonance. This exploratory calculation is performed using a lattice discretization of QCD with quark masses corresponding to mπ400~MeV. We obtain a description of the energy dependence of the transition amplitude, constrained at 48 kinematic points, that we can analytically continue to the ρ pole and identify from its residue the ρπγ form factor.


    Last year

    https://www.annualreviews.org/doi/full/10.1146/annurev-nucl-102419-033316

    We review the ab initio symmetry-adapted (SA) framework for determining the structure of stable and unstable nuclei, along with related electroweak, decay, and reaction processes. This framework utilizes the dominant symmetry of nuclear dynamics, the shape-related symplectic eq-033316-001.gif symmetry, which has been shown to emerge from first principles and to expose dominant degrees of freedom that are collective in nature, even in the lightest species or seemingly spherical states. This feature is illustrated for a broad scope of nuclei ranging from helium to titanium isotopes, enabled by recent developments of the ab initio SA no-core shell model expanded to the continuum through the use of the SA basis and that of the resonating group method. The review focuses on energies, electromagnetic transitions, quadrupole and magnetic moments, radii, form factors, and response function moments for ground-state rotational bands and giant resonances. The method also determines the structure of reaction fragments that is used to calculate decay widths and α-capture reactions for simulated X-ray burst abundance patterns, as well as nucleon–nucleus interactions for cross sections and other reaction observables.


    Progress!

  • https://arxiv.org/abs/2208.07245


    Well worth everybody's time.

    Absolutely!


    Glad to see LENR embracing mainstream science cutting edge type 2 theories and experiments!


    And there is a lot of reasonable hope that these could lead to useful low small-scale fusion. And some chance of type 1 - though it seems unlikely (why should we have resonances that result in no obxervable high energy products - a bit of a coincidence!)


    THH

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