Eric Walker New Member
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Posts by Eric Walker

    2. Human Psychology

    This is certainly helpful as well for trying to make sense of the skeptical response to some of the more solid LENR research, for sure. Thomas Kuhn is helpful as well, and Paul Feyerabend can help on the methodological side.


    But your point is well taken. One must approach each LENR study on its merits, with a discriminating eye and a healthy dose of skepticism, in the same way that scientists apply skepticism to claims put forward in their own fields.

    So I just took a look at Investigation of light ion fusion reactions with plasma discharges, an arXiv paper later published in 2019 in the Journal of Applied Physics. This is a Google-funded investigation by Thomas Schenkle and others at Lawrence Berkeley National Laboratory into a 2005 study, DD reaction enhancement and X-ray generation in a high-current pulsed glow discharge in deuterium with titanium cathode at 0.8–2.45 kV, by Lipson, Rusetskii, Karabut and Miley, all of whom are pretty well-known in LENR circles.


    In the 2005 paper, Lipson and the others reported a screening potential in the glow discharge regime of Ue = 610 ± 150 eV for dd reactions. This is the correction you would need to apply to the formula for fusion of bare deuterium nuclei to account for the rate of reactions they were seeing. By contrast, according Schenkle et al., the screening expected for fusion in a plasma would be Ue = 27 eV.


    Schenkle et al. report an even larger screening potential of 1000 ± 250 eV in their own glow discharge experiment than Lipson et al.'s value of 610 ± 150 eV. In contrast to Lipson, Schenkle and the others did not see evidence of tritium in their ex situ (after the fact) measurements of the palladium and titanium cathodes. They estimate that the ratio of 3He to t production from the different dd reaction pathways to be close to the value of 1 reported over the years.


    Despite not seeing tritium, the LBNL study is a replication of the Lipson screening potential reported in 2005, with an even higher value than that calculated in the 2005 study. Schenkle et al. did not have the instruments to go down to as low a voltage as in the Lipson paper, and Schenkle reported fusion results only in connection with palladium cathodes and did not mention results for titanium cathodes, in contrast to Lipson et al., who used titanium cathodes. Schenkle and the others want to measure the tritium more carefully in a future experiment.


    I think Ahlfors wants to call into question the neutron measurements that the LBNL team used to derive their screening potential of 1000 ± 250 eV, which is not something I can comment on.


    The 2005 report by Lipson, Rusetskii, Karabut and Miley is technically LENR, in the sense that the energies that are being used are pretty low. But the experiment is basically a normal fusion experiment using lower energies and bears little obvious resemblance to the Pons and Fleischmann experiment and other LENR experiments with cathodes, electrolytes, transmutations and so on that people may be more familiar with. Nonetheless I think it's pretty cool that the Lipson paper received some amount of confirmation 14 years later by the LBNL group.

    the word 'conclude' is ambitious withour further evidence..

    I would tend to use the word speculate.. as in

    "Activation of Er and Hf is reasonabe to speculate"

    I am happy to call this speculation on my part, as I'm just a hobbyist.


    In addition to the other evidence of neutrons present in the system in the case of the deuterated materials (the activated Gd and Cd, the CR-39 pits, the bubble dosimeters), note as well that some of the short-lived species (163Er, 171Er, 181Hf) were ones with 1 neutron greater in mass than species present in nature (162Er, 170Er, 180Hf). If several lines of evidence show neutrons doing other things, I would be surprised if Er and Hf were not activated by the same neutrons.


    The authors assume neutron activation, writing that "there are several plausible mechanisms for the observed neutron activations". Their question, and the thing that is interesting in this experiment, is to figure out what caused the neutron activation (and the activating neutrons).

    For anyone coming up to speed on this topic, there was a Nature commentary in May 2019 that said that the results of the Google collaboration "have been published across 12 papers over the past 2 years: 9 in peer-reviewed journals and 3 on the arXiv preprint server."


    I attempted to track down those papers by following links here and elsewhere (many thanks to Ahlfors and others). I don't think I found all 12 of the ones mentioned above, and there might be others in addition below that were not available at the time of the Nature commentary:



    I think there was a study that was mentioned that sought tritium and didn't find it, perhaps with Thomas Schenkel as an author, but I didn't manage to track it down. Thomas Schenkel is at Lawrence Berkeley National Laboratory and is one of the four (?) Google-funded principal investigators who have assembled teams. The other three principal investigators are Curtis Berlinguette, at the University of British Columbia, Yet-Ming Chiang, at MIT, and someone at the University of Maryland, perhaps Jeremy Munday. So many of the papers have one of these people as coauthors. In addition, it seems that Matthew Trevithick, David Fork, and Ross Koningstein, all at Google, are mentioned in connection with the Google project as well.

    RobertBryant interesting analysis. The primary cross sections to look for would be for the slow neutrons from the (hypothetical) deuterium photodissociation, whose maximum energy Steinmetz et al. give at 0.087 MeV. Slow neutron capture, as you know, has a large cross section. It's from these neutrons that I'd expect to see most of the activation. Activation of Er and Hf is reasonable to conclude, given that Gd and Cd, the witness materials that were used in the experiment, were also activated, and given that they picked up neutrons in the CR-39 and bubble detectors.


    There appear to have been a range of neutron energies present. In the CR-39, triple pits were observed, implying some neutrons with energy >10 MeV.


    Although (n,2n) reactions with something in the setup might be possible (I'm not sure how likely), other possibilities include prompt and beta-delayed neutron emission from unstable daughters following slow neutron capture. The following reactions are energetically possible, although I don't have the neutron capture cross sections and branching ratios (and hence likelihoods).

    Code
    n + 167Er → 81As + 87Br + 91206 keV                     →β-, →β-n
    n + 170Er → 84Se + 87Se + 90336 keV                     →β-, →β-n
    n + 168Er → 84As + 85Br + 89510 keV                     →β-, →β-n
    n + 168Er → 83Ge + 86Kr + 89323 keV                     →β-, →β-n
    n + 166Er → 80As + 87Br + 89252 keV                     →β-, →β-n

    In each of these cases, there is a beta-delayed neutron emission in one of the unstable daughters (e.g., 87Br). My little helper program produced 340,369 of reactions like these that lead to beta-delayed neutron emission. These ones have energies in the range of ~90 MeV, which seems implausible and hence unlikely, but among 340k reactions, perhaps a few are likely. I also see that prompt neutron emission from an unstable daughter is energetically possible:

    Code
    n + 166Er → 25O + 142Nd + 1746 keV                      →n
    n + 170Er → 25O + 146Nd + 1538 keV                      →n
    n + 168Er → 25O + 144Nd + 1479 keV                      →n, →α
    n + 167Er → 25O + 143Nd + 1433 keV                      →n

    Again, no cross sections or branching ratios to weed out the unlikely reactions, unfortunately, but you get the idea.


    Given the vast permutations of energetically possible reactions of these kinds and others, and my lack of familiarity with gamma spectra, I would hesitate to speculate about individual lines in the spectra.

    The paper by Steinetz et al. is interesting. They set up a beam of gamma photons emitted from a LINAC with energy <2 MeV pointed at a target of one of erbium hydride, erbium deuteride, halfnium hydride or halfnium deuteride. When deuterium was used, gamma lines for short lived isotopes of Er and Hf were observed, and neutrons were seen in integrating bubble dosimeters and CR-39, and gamma lines were seen for activated Gd and Cd, the latter two materials present as a "witness" material for neutron activation. When hydrogen was used, there was no evidence of any activity above background.


    Steinetz et. al rule out photoneutrons from the dissociation of deuterium on the basis of (1) the gamma photons from the LINAC being below the deuterium dissociation energy of 2.225 MeV, and (2) the presence of energetic neutrons, which would not be yielded by photodisintegration of deuterium. They rule out a gamma-n process in which neutrons are removed from one of the heavier elements because (1) this would require more energy than the <2 MeV photons from the LINAC and (2) you'd see this happening with the hydride samples as well as the deuteride samples, which wasn't the case.


    I want to draw the following conclusions from this paper:

    • They might well be seeing something interesting
    • The 171Er and other short-lived isotopes are due to neutron activation of the erbium, halfnium, etc.

    I question their ruling out photoneutrons from deuterium. First, their LINAC source is capable of producing 2.4 MeV photons, and they had to modify the system to reduce the beam energy. Did they do that correctly? If they did not, you'd have photons of sufficient energy. Second, the presence of fast neutrons shown by the CR-39 and bubble dosimeters does not rule out photodissociation of deuterium. There are various (n,2n) reactions, and beta-delayed neutron emissions in some cases when a daughter nuclide is unstable, in which one (perhaps slow) neutron is absorbed, and one or more fast neutrons are yielded with enough energy to be picked up in the bubble dosimeters and CR-39 chips.


    One thing that stood out in my mind as I read through the paper is that with the presence of MeV gamma photons, this seems to be more in the realm of normal nuclear reactions than LENR.

    rather than boring it is rather interesting to observe the strong Er171 emissions .. since Er171 is not a "naturally" stable isotope... was Er171 produced from Er167??

    An important column in the Wikipedia table of erbium isotopes is the natural abundance (two columns at the far right). These columns show that only observationally stable isotopes of erbium are found in nature. 171Er, with its half-life of ~ 7 hours, will only be found in unusual circumstances, as you allude, e.g., by neutron activation of 170Er, which is a natural isotope. If someone reported the gamma lines for 171Er, that would be interesting, for sure. Out of curiosity, do you have a link to the paper with the graph showing the 171Er gamma lines?


    But one imagines the 171Er in this case is just a "witness" to whatever else is going on, and erbium would not necessarily be driving whatever is going on. I.e., perhaps it's a side effect of some other process. If I had no other context, I'd start with neutron activation of 170Er as the initial hypothesis and work from there to confirm it or rule it out. We've already seen evidence of neutrons in the context of the NASA bubble dosimeter experiment, which unfortunately didn't impress Alhfors.


    Basing an experiment around pure erbium would still be boring, I imagine. :)

    Erbium has no naturally occurring unstable isotopes, and it's not very heavy, in the big scheme of things, so my prediction — (1) in the case of an erbium hydride or deuteride that shows activity, the activity will be traced back to some natural impurity, and (2) pure erbium will be boring. (Predictions are good because they can be falsified.)

    They used Pt as anode in both experimental and control, so this would answer Eric Walker 's doubts about the potential radiation detected coming from the emitting Pt isotopes.

    Curbina in the case of Frank Gordon's tabletop experiment, I was wondering whether induced alpha decay of Pt (190Pt) was possibly the source of the weak ionizing radiation (perhaps electrons), on the order of 3-30 eV, that Bruce__H mentioned. If 190Pt was the source, that would be very cool and would be new physics, because, theoretically, alpha decay is not something you can induce in a tabletop experiment. It would be a great day if subsequent investigation showed Frank's experiment to be reliable and reproduceable and that the important variable was the Pt anodes used in the codeposition. LENR would be vindicated. You'd no doubt want to swap out the anode material with something else as a step in putting such a conclusion on a firmer basis.


    In the case of the NASA neutron bubble detector experiments and controls, Pt was present in both cases and so not really controlled for; the control runs in were apparently controlling for other variables. So the relationship of platinum to the NASA setup is unclear and not shown to be neutral.


    Was there an indirect relation? Assume for the moment that platinum is involved in the NASA findings. Perhaps the control solution decreased codeposition of platinum from the anode and so platinum still played a role, but less of one. But more importantly, in case of the NASA experiment, the observable is the measured dose in the dosimeters, which could well be due to some phenomenon different from that causing the eV-level ionizing radiation seen in Frank Gordon's experiment. And the NASA experiment involved electrochemical cells rather than interaction with hydrogen. The NASA neutron experiment must be considered on its own terms. Presumably there are neutrons involved, and, in the case of the triple pits in similar CR-39 experiments, alpha particles as well. It's not obvious on its face that there's a connection to Frank Gordon's experiment, although there might be one. The differences in the two experiments are significant, making the experiments hard to compare. This is the case, even if neither experiment is due to artifact and some form of LENR is involved in both.

    Frank Gordon came here to pass on his knowledge in the hope of spurring on replication attempts, not to be lectured. How about we trust he has thought these things out, and take it from there? After all, he has been at this 30+ years.

    I don't have any advice to give Frank Gordon, and certainly no lecture to offer him. My hope was to explain to Curbina why I was interested in the platinum anode used in the codeposition, which I was having a hard time conveying. Perhaps one day someone will look at this question. In the meantime, I'll try not to muddy the thread with tangential discussion.

    My thoughts weren't an attempt to explain all anomalous effects in one go, e.g., in thin film experiments, or ones using molybdenum. My assumptions are as follows:

    1. Some of the experiments are poorly controlled and mistake artifact for something unknown
    2. Of the remaining experiments, there may be related but different phenomena (induced beta decay in one case, induced alpha decay in another, etc.)
    3. Within a single category of phenomenon, there may be different materials involved (platinum in this case, another element/isotope in another case, etc.)

    So the details of specific experiments matter a lot. I can relate to the desire to generalize. But first I think it's important to handle each combination of parameters (experiment type, materials used, observables, etc.) on its own terms. In this context, whether platinum is being electroplated onto the active surface that Frank Gordon is reporting on is an important variable to understand, explore, and control for. If the platinum is taken away, does Gordon still see the ionizing radiation? Different answers lead to different avenues for further exploration.

    Curbina perhaps there's another anode material that can be substituted for platinum other than gold or carbon? The ever-present platinum anode is an overlooked variable that should be considered and controlled for.


    The reason I bring up the question — platinum has a trace alpha emitter in the form of 190Pt. An interesting possibility that would be nice to rule out is that this alpha emitter is what is indirectly causing the activity. The 190Pt → 186Os transition yields a 3.25 MeV helium nucleus. If these things occasionally fire off, you would get residual ionizing activity as the helium nucleus comes to a stop, but not necessarily keV electrons. It would be nice to remove platinum from the mix and either verify that the activity continues to be seen or that it is no longer seen.


    This is with the question in mind of whether the hydrogen loading is spiking the activity of the alpha emitter in this case (which would be new physics).

    RobertBryant I did not clarify that I was wondering whether the beta decay had been "accelerated" as a side effect of the loading of the hydrogen. So more disintegrations per second than normal 107Pd in the wild. Needless to say, if beta decay were being induced somehow, this would be an interesting result requiring explanation.


    As to actual power, it might well be negligible in this case. The interesting observable to be explained or explained away is the ionizing radiation.

    While waiting on the new thread to be split off from this one, I would just note that palladium includes an isotope that is a beta emitter. 107Pd is a beta emitter that is present in trace amounts, and the 107Pd → 107Ag transition yields a 34 keV beta electron. That is 1000 times hotter than the upper limit of 30 eV mentioned by Bruce__H, so either the beta transition can be ruled out as the source of the ionization, or the upper limit, perhaps computed indirectly from a population of ionized atoms in the chamber of the detector, is wrong. I mention all of this this because I would have liked the source of the ionization to be 107Pd. But it's probably not.

    In the Nature article about Google's efforts linked to in the HowStuffWorks overview, from 2019 (I've been out of this for a while), we have Dr. Close of CF replication infamy:

    Some scientists welcomed the scrutiny brought by the Google project. But Frank Close, a theoretical physicist at the University of Oxford, UK, says that the scientific mainstream has shunned the topic for good reason: no one has managed to independently reproduce the finding and more worthwhile topics have emerged, he says. “There is no theoretical reason to expect cold fusion to be possible, and a vast amount of well-established science that says it should be impossible,” says Close, who was involved in efforts to replicate the original 1989 experiment.

    This blithe writing off of the CMNS research was always frustrating for me to see. You can surely challenge specific papers on specific points. But dismissing a whole corpus of work out of hand isn't a thing, or at least it shouldn't be. And, of course, Close's lacking a theoretical reason just means that he has been fixated on ruling out a specific mechanism whose parameter space he has a lot of confidence he understands, and apparently he has not been susceptible to the intrusion of any kind of lateral thinking.


    It's great to see Google have been following up on this since 2015, and it's promising that Nature were willing to publish an overview of the Google work, even if they hedge things significantly. Perhaps the taboo on this kind of research will gradually lift.

    From the article, quoting Peljo with the HERMES project,

    Quote

    "Originally, Pons and Fleischmann observed excess heat, but there are reports of other anomalous effects, such as neutron radiation or helium production. But there are a lot of reproducibility issues. Most likely, these reactions are not actually fusion, but instead some other nuclear reactions taking place in the metal lattice."

    This last idea has been my working hypothesis as well, namely, that the helium in the original P&F experiment was real, but the result of accelerated alpha decay instead of deuterium-deuterium fusion. Hopefully the HERMES people do not try to control variables too strictly by using palladium that is ultra pure or something. If my hunch is in the right direction, it could well be some other element in the mix that was involved that came along with the palladium or with the platinum electrodes.


    Glad to see that there's a glimmer of effort on the mainstream science side of things to try to bridge the gap with what the LENR researchers are reporting.