Side note: my argument (really William Barker's argument) is interesting if the decay rate is sensitive to changes in the screening or other features of the atomic electron shell, regardless of whether the rate goes up or down as a function of screening.
Thanks, H-G, I'll take a look when I have a moment. The first question that comes to mind is whether that paper is focused on a minor adjustment to make the larger calculation more accurate. It makes sense that in addition to whatever else electrons do, they would slow down the alpha particle a small amount.
In the meantime, here's a response on physics.stackexchange.com that supports my interpretation qualitatively (although note the quantitative challenge it hints at):
Another way to see support for my interpretation is to plug in values for A and Z into this calculator that imply protons are being screened and observe which directions the decay constant and half-life go: http://hyperphysics.phy-astr.g…hbase/Nuclear/alpdec.html.
Any example on that? ... Of course, that is not to say that e.g. removing the electrons would not speed up the decay. The question is, with how much.
Yes, how much is the central question. Note that according to the Gamow calculation, it is adding an electron that speeds up the decay rate, not the other way around. That is because the width of the coulomb barrier decreases a small amount as a result. Despite your (good) reasoning, why does the process of decay work this way (assuming it does)? I don't really know. We get a hint that it works this way, however, in the case of oblong deformed heavy nuclei: it is at the poles that alpha decay is more likely, where there is less Coulomb barrier to traverse for the alpha particle to escape, than at the waist, where there is more Coulomb barrier. Nature is weird.
Here is an example of the dependence of the Gamow decay rate on relative screening. Consider the decay 190Pt → 4He + 186Os + 3252 keV. Here are the predicted half-lives in years as a function of the number of additional electrons screening out protons in the nucleus:
Electrons Half-life (years) 0 1.4e+12 1 2.7e+11 2 4.9e+10 3 9.1e+09 4 1.6e+09 5 3.1e+08 6 5.7e+07 7 1.0e+07 8 2.0e+06 9 3.8e+05
With the addition of 10 electrons, we've brought the half-life of 190Pt down from 1.4e+12 years to 3.8e+05 years. (Calculations here.) This result will hopefully establish that the alpha decay rate is quite sensitive in the Coulomb barrier width (which depends upon the contribution of bound electrons). A similar dependence is seen in the spontaneous fission cross section, an estimate of which can be obtained using the same calculation with different daughters. As Hyperphysics says, "The forces inside the nucleus are balanced on a razor's edge."
There is a valid complaint here: where are you going to get 10 electrons to zero out the contribution of 10 protons on the Coulomb barrier? That is a good question. Here is where it is important to take a closer look at the assumptions in the Gamow calculation. First, it assumes a spherically uniform distribution of charge. What happens if that assumption is violated? Second, it applies to the steady state system. What happens when there are transients in the contribution of electrons to the system, e.g., under the influence of perturbations of various kinds (e.g., those described in William Barker's patent, or in the Simakin and Shafeev paper)?
My high-level conclusions: (1) the Gamow calculation swings across orders of magnitude as a response to a change of inputs, and (2) there may be cases that have not been worked into the calculation that are at play in real life in poorly studied scenarios that cause the result to be even more sensitive to inputs.
So, I submit that the OP counts as interesting, but at this stage of the game (even granting the assumption of partnership in the enthusiastic sense that OP used - and I firmly believe that sense is inappropriate) calling it "important" seems a gross exaggeration.
Your points are all good, but one detail to mention to give additional context. There's the question of whether what GEC are looking into is a thing, scientifically speaking (and, by extension, a possible variant of LENR). And there's the question of whether it can be turned into a practical source of energy.
Most of the arguments here and elsewhere over the past three decades have focused on the first question — is LENR/cold fusion scientifically a thing? The question of eventual power generation is a speculative side discussion. If/at such a time as there is mainstream scientific consensus that LENR has an experimental basis, the question of terrestrial power generation will become an interesting one. It seems to me that it would be premature to make any pronouncements about the promise of GEC's process for power generation before getting everyone on the same page about whether it has a scientific basis, given the unknowns.
anyone can live in hope, although as we have seen with Rossi it can be foolish to live in too much hope.
Your point is a reasonable one, THH. But I think it would be a mistake to compare the quality of the hope raised by folks of the caliber of Tom Claytor, Brian Oliver and Robert Duncan, on one hand, and Rossi, on the other. Over the years there have been a number of experimentalists with relevant training who, having looked into the matter, have said "there seems to be something there." That provides the basis for a qualitatively different kind of hope than, for example, Rossi's antics.
This fact in conjunction with the high kinetic energy of the alpha particle makes me believe that the influence from minor deformations of the electron cloud due to external electric fields on the alpha decay rate must be minute.
Your analysis takes you away from the quantum mechanical one by getting too concrete with the details. The Gamow theory of alpha decay is understood to be an early, relatively accurate attempt to model the rate of alpha decay quantitatively. It's an early attempt, because a genuine quantum mechanic these days would disavow the ability to know whether there is an alpha particle rattling around the nucleus, trying to escape. Nonetheless the theory is remarkably accurate, because by hook or by crook it is able to estimate the alpha decay rate to within one or two or three orders of magnitude or so in a subset of cases. That may not sound very accurate, but consider that alpha decay rates range over some 20 orders of magnitude (going from memory).
Change the Coulomb barrier width a small amount, and out of the calculation comes an alpha decay rate that is different by some orders of magnitude than it would otherwise have been. How do electrons factor into this? Their negative charge alters the width of the Coulomb barrier (which surrounds the nucleus), making it more or less likely for this kind of transition to occur (actual mechanism unknown). This is what the Gamow calculation assumes. How does all of this actually work under the hood? One can only speculate, as you have done admirably above, along the lines of Gamow himself.
The case of oblong deformed heavy nuclei is an interesting and illustrative one. Alpha particles are more likely to be emitted at the poles of these nuclei, where there is less of a Coulomb barrier to traverse, than at the waist.
I'm going to speculate that you can assume that the electron cloud penetrating the nucleus (and, around the nucleus, the Coulomb barrier) is not spherical, given the various p, d and other non-spherical electron shells. Does this matter, in light of the constant smearing of the electron orbitals as they rotate around in three dimensions? I suspect it does matter, because the timescale on which nuclear events occurs is much faster than that that pertains to the activity of electrons. I'm going to guess that you can assume in the steady that state the electron cloud is radially symmetric around the nucleus. What happens when there is some asymmetry that is momentarily introduced? Perhaps not much, as you have suggested. Alternatively, perhaps there will be significant tidal forces that come into play as the very short-range and very strong nuclear force works to compensate against Coulomb repulsion of the protons in a Coulomb field that is no longer radially symmetric.
Given the uncertainties in how the whole process works, and the dubious assumption of spherical distribution, there's a question in my mind as to whether the shell theorem will be of help here.
So, basically, I can be obnoxious as long as I'm politely and engagingly so?
Unfortunately ... yes, kind of? Knowing from a distance who's politely trolling and who genuinely has eccentric views is a hard problem.
Indeed and that included many here and especially on Vortex. And many of them were condescending or exceedingly unpleasant and rude to the skeptics.
Yes, indeed. I apologize for any rudeness I might have shown to skeptics on my part on Vortex. Keep in mind that the people there and on this forum are just amateurs and hobbyists, usually without any particular basis to judge claims, and often unaware of the limits of their own knowledge. We're like spectators watching and cheering on different teams in a game.
Rossi also fooled Nobel winner Dr. Brian Josephson (hook, line and sinker) and no less than McKubre
I'm pretty sure you have McKubre's position wrong, and I suspect you have Josephson's position wrong as well. As I understand it, both of them have approached Rossi with considerably more nuance than this statement implies.
Along the way, a number of skeptics were banned from Vortex, their posts were censored elsewhere,
The skeptics on Vortex (whose views I always found interesting, even if I disagreed on particular points) regularly fell afoul of the no-sneering rule. Keep in mind that Vortex was conceived as a refuge to explore weird and heretical ideas away from the kind of harsh criticism encountered on newsgroups like sci.physics.fusion. One may disagree with the soundness or wisdom of such a rule, but it's there. (Our version of that rule is much more relaxed and relates to whether a person is being a boor.)
It [the Gamow barrier calculation] has nothing to do with possible influence from an external electric field on an atomic nucleus.
The Gamow theory of alpha decay can be used to estimate the spontaneous fission cross section, as the process is very similar to alpha decay. The Gamow theory of alpha decay has as one of its variables the Coulomb barrier width. The Coulomb barrier width is a function of electron screening from the bound electrons. The shape of the electron cloud surrounding an atom and nucleus depends in part upon the external electric field, so your conclusion does not (necessarily) follow.
Take a strong electric field like 10E6 V/m. The size of a uranium nucleus is around 15E-15 m. The voltage drop over the nucleus will be less than 1.5E-7 V, probably much less because the electron cloud will shield the nucleus from most of the electric field.
Just an example of what might be needed which is not inconsistent with this: a slight distorting of the electron cloud surrounding the nucleus might alter the screening a small but appreciable amount. The Gamow barrier calculation is extremely sensitive to minute changes in barrier width, so not much of a change would be required. There could also be an outsize effect from transient asymmetries in this screening across the nuclear volume.
The evidence of a nuclear reaction is violent and easy to detect, comparable to a bank robbery where the evidence is a blown open safe and shrapnel in the opposite wall. ... That's how quantum mechanics works, like it or not.
This is a truism. What will make it insightful will be to apply it to the specific details of specific experiments. Alpha decay, for example, is straightforward to detect under the right circumstances. But it could be occurring in an electrochemical cell and very difficult to detect on the other side of the cell wall.
Since Barkers prescription for increasing radioactive decay rate is comparable to homeopathy take away possible placebo effect it is safe to say that he could not have done it in the way that is described in the patent. ... It would be like trying to cure cancer with a glass of plain water.
H-G, you're approaching this question like the medieval schoolmen: ruling out an empirical claim by reasoning from first principles. One is probably safe doing this with very far-out claims. But Barker's patent is definitely not in the realm of homeopathy; it's setting out empirical details, and it comes with an explanation (at the nuclear level) that if one squints one's eyes is not incoherent. What is needed, then, is to test Barker's claim empirically, possibly enlisting his help if he's still around. It seems plausible that people will sometimes overlay their imperfect understanding of what's going on on top of what they're doing and arrive at the wrong justification for why things seem to be working.
"This is stupid. Things cannot be subjected to an electric potential, only to electric fields. There is no electric field inside the terminal. It forms a Faraday's cage."
"William Barker's insights into electrostatics has not improved since his previous patent on the subject. The same goes for the patent engineer."
Ok. But is what Barker was claiming in the patent about the change in activity of uranium isotopes true, and can it be scientifically verified?
"This choice of an example kind [Barker's patent] of makes the point. It’s not LENR. There are no nuclear reactions claimed."
I may have missed the gist of your point, but I think we make too many assumptions by concluding that Barker's (claimed) speeding up of spontaneous fission is not LENR.
"As for the patent, well sometimes patents are granted for claims that have not been realized, and considering that this idea has not been widely implemented and has not resulted in fame and glory for the inventor, it’s a safe bet this is one of those patents."
I will allow that. But the patent still provides the basis for an interesting set of experiments to attempt to replicate what he's describing; if he's still around, he might be able to help out.
"I don’t know if one should take seriously an inventor who thinks 2 of the 3 most important isotopes in nuclear waste are U-238 and U-235. U-238 is not particularly radioactive ... it says something about the inventor’s competence in the field, in addition to the point made by HGB."
If Barker implied in his patent that the remediation of uranium isotopes is important in the fission industry, I think the matter of his knowledge of the economics of the industry (or his too quickly writing a patent) gives only indirect information about whether he found something interesting. Scientists who require solid evidence of competence obviously may be scared away. But there are also good scientists who have more of an appetite for adventure. The important question, of course, is whether there is any substance to Barker's claims.
"Ah yes, nature contrives to make any unambiguous indication of LENR inconsistent with whatever mechanism might be at play."
That wasn't quite my point; I'm optimistic that if LENR exists, it can be nailed down in more than one way. The thing I wonder about is whether you're going to get novel nuclides along the lines you suggested and to which suggestion I responded.
“If fission is to be exothermic, then there has to be an excess of neutrons (not counting alpha decay as fission). The increase in binding energy per nucleon resulting from fission is because of the long-range repulsive Coulomb force is compensated by additional neutrons as the size increases beyond mid-size.”
Starting from naturally occurring isotopes, fission is (hypothetically) exothermic in elements as light as strontium:
84Sr → 30Si + 54Cr + 717 keV (both daughters naturally occurring)
84Sr → 34S + 50Ti + 713 keV (both daughters naturally occuring)
Here’s zirconium, two places down the chart:
96Zr → 48Ca + 48Ca + 3005 keV (both daughters naturally occurring)
94Zr → 46Ca + 48Ca + 92 keV (both daughters naturally occurring)
These are the only exothermic (2-daughter) branches starting from naturally occurring parents; notice the pattern of stable daughters. The challenge here, of course, is that the lighter the parent, the more infinitesimally small the spontaneous fission cross section.
“Again, fission of a medium mass would not be exothermic (not considering alpha decay as fission). And the unstable products are not necessarily short-lived. Ni-64 to two Si-28 (half-life 153 years).”
Your 64Ni fission is not a good example, because the hypothetical transition would be endothermic by 33 MeV.
A better way to model this problem is to use the Gamow calculation to calculate the fission cross sections under various amounts of electron screening, to use heavier parent nuclides, and to allow alpha decay as a decay channel. I propose that platinum (present as the anode in nearly every electrochemical experiment), lead and mercury are better candidates. With the cross sections calculated, it’s possible to find the probability of the different possible daughters. My recollection (it's been a while) is that when you run the numbers using various amounts of electron screening, the fission daughters are either stable or have very short half-lives to stable nuclides.
It is important to include alpha decay in such calculations, both because it is a very similar process to spontaneous fission, and because it can potentially make sense of the heat-helium correlation.
“In any case, radiation associated with such unstable nuclides (even short-lived) would be highly specific identifying the nuclide unambiguously. I have not seen such claims.”
Another claim of speeding up fission (thorium-232) can be found here:
In this case they used lasers to (allegedly) speed up the natural activity and measured it using gamma spectrometry.
"Many of the claimed transmutations are from neutron or 'dineutron' or proton capture, sometimes several steps with unstable intermediates."
I agree that if there were neutron capture, "dineutron" capture, proton capture or detueron capture, the products would generally be unstable. The first thing I do when reading a LENR paper is to ignore or forget whatever suggested explanation is provided and just focus on the experimental section.
"And fission usually produces unstable products because of excess neutrons."
Because fission in general is a synonym for actinide fission, the parents are so heavy that the daughters lie far from the line of stability.
"Stable products are characteristic of very long time periods for the unstables to decay. Immediate products of most reactions involve unstable products in general. And since they claim dozens of transmutation products, it is not plausible that not one would be sufficiently unstable to generate measurable radiation."
There are multiple claims of short-lived radiation (e.g., half-lives of hours). This would be expected of very light fission daughters if fission of a medium mass nucleus could be engineered.
"The SPAWAR group is claiming to be able to induce fission and to stabilize radioactive waste. Well, instead of making such claims based on supposed evidence of stable starting and ending points, or disputed evidence of neutrons, why doesn't someone somewhere take a radioactive source and demonstrate that they can reduce the activity? Or take a stable sample, and demonstrate they can increase the activity? *That* kind of transmutation could be detected at far far lower levels, and the measurements would be far more specific than mass spectrometry of stable atoms."
I very much agree. I await the day that LENR researchers who claim reliable results will take a a closer look at radioactive nuclides and try to tackle these questions.
"In spite of all the blue sky talk of waste remediation, I am not aware of a single claim where they have been able to change the activity of any sample up or down."
Not sure I fully understand your complaint, but there are several such claims, e.g., as made in this 1987 patent by William Barker:
I vaguely recall claims to change activity among LENR researchers, e.g. George Miley. The question for me is whether there is any reproducible "lab rat" experiment to be found among or derived from such experiments.
"Or for that matter, produced a stable nuclide not abundantly present in nature."
This would surely be interesting, but possibly inconsistent with whatever mechanism might be at play assuming a subset of LENR results are real.
Some interesting discussion and debate after a long dry spell.
Of the more than 3000 nuclides that have been experimentally characterized, only 253 are stable, so the production of unstable products in nuclear reactions (especially involving larger nuclides) is overwhelmingly favored
This is assuming something like neutron addition. If the process is akin to spontaneous fission, stable and very short-lived radionuclides might be expected.
(Here I am weighing in on the matter of what are purportedly stable daughters, not the matter of generating neutrons to drive further reactions.)
I gather, nul-points , that you're hear more to assist against trouble makers than to discuss LENR and related topics. I advise against assisting against putative trouble makers in any way other than addressing topical points that they make, politely correcting their factual basis if necessary.
i think it's necessary to go slightly further back in time to get a representative overview of the 'interesting points' offered from that source, Eric
We're not, to my knowledge, attempting to arrive at an overall assessment of H-G's character or contribution (nor should we). I mentioned the matter of some substantive points he raised, some of which I just mentioned.
Did this result in a round of informed discussion from the questioner? If you're interested an example of 'the merits' of his contributions, why not scroll back a little and see how interested he really was after his questions had been answered?
You appear to be seeking to make a case against H-G. In doing so, you are overlooking some substantive discussion I just referred to and are getting into matters of character (ad hominem). If his questions have been addressed elsewhere, please refresh our memory as to what the answers were or bring additional information you may be aware of to bear on the discussion. When papers are mentioned, it's good to extract the relevant concepts and weave them into the discussion, relating them to earlier things that have been said.
When we focus instead on H-G's alleged unworthiness, we allow the discussion to be detained in tangents about people's personalities rather than considering facts and science. Although some people will try to score points, as you say, intelligent readers will not be distracted by weak arguments, which can always be politely rebutted. And the points H-G made above that I referred to were not weak ones.
nul-points , since you ask, I'll quote the points H-G made that I think are interesting, if you'd like to address them (or perhaps not):
"several pictures of microscopic tracks on various surfaces have been shown in some threads on this forum. For lack of other explanation they have been ascribed to 'strange radiation'. ... Certainly a single Strange Radiation Particle cannot generate tracks like these. It would take a beam of such particles. This beam must be deflected and perhaps also modulated to create the repetitive patterns that distinguish those tracks."
"Finely focused particle beams do not materialize spontaneously, they have to be engineered using a particle already known to science."
Is there anything there you agree with? Is there anything you disagree with? These are statements H-G made, and they can be considered and addressed on their merits.