NASA: New Paper about Experimental Progress

Quote from THHuxleynew

Axil, there is nothing in the latest best writeup of the Cravens demo that shows excess heat!

The differential temperature data comes from thermocouples sealed into the globes which have different atmospheres. The D2 (reducing) atmosphere is known (from the TC datasheet) to lead to possible drift errors in the not industrially robust thermocouples which would exactly cause the stated apparent result. H2 vs D2 leads to different diffusion rates and therefore drift.

So I don't see how you can know SmCo5 magnets generate excess heat via nuclear effects. Even if the Craven demo were proven to mean real excess heat and therefore (possibly) nuclear level effects, there is absolutely no way to know which element of the demo causes that effect.

'Golden Balls' Cravens

http://www.infinite-energy.com/images/pdfs/NIWeekCravens.pdf

On excess heat

Quote

The four-inch spheres don’t look special except for the temperature sensor

inserted to measure its core temperature. Calibration studies,

using a similar sphere, show that the warm sphere is generating

1 watt heat at ΔT of 4°C

on the nuclear origin of the heat

Quote

Most importantly, there is no power connected

to the sphere. It just sits and stays warm for

days/months on end.

"starting from the proposition that whatever it is we are talking about is". right

It might be to do with the high magnetic field increasing the screening effect of the

metal... is it gold or palladium or an alloy?

Axial says that the magnet creates a shifting vortex of field lines, apparently some nonuniformity

is necessary to get variations in the charge distributions around the deuterium nuclei.

Maybe Axil could ask Estevez, the author of the "few eV's paper"

What effect a samarium cobalt magnet might have on the screening effect?

Would it be sufficient to bring the activation energy down to near 100C, or 0.03eV?

[email protected]

Quote from axil

Muon-induced fission in 235U and 238U

That's an interesting paper. One way for fission to occur is to have a low-lying unstable state populated by an event such as a muon capture. Presumably there are no such low-lying states in 235U and 238U, as normally normally the addition of MeV of energy from a slow or fast neutron capture is required to induce fission. So perhaps it is charge screening from the captured muon that is responsible.

There is another paper you pointed to a few years ago about laser-induced alpha decay of U232, which I had in the back of my mind when I raised the question on PhysicsForums: https://arxiv.org/pdf/1112.6276.pdf.

Regarding https://arxiv.org/pdf/1112.6276.pdf

This is one of my favored papers because it shows how surface plasmon polaritons produce fission in uranium by catalizing muons.

The creation of polaritons through the stimulation of gold nanoparticles demonstrates how the LENR reaction works in dusty plasma. Nanoparticles produce polaritons that in turn produce magnetic flux lines that intern produce proton decay that in turn produce muons that in turn produce the fission of uranium.

No fission happens when the gold nanoparticles are removed from the experiment.

It is the dust in the dusty plasma that produces the polaritons. The polaritons are created between the particles of dust.

Here is how particles produce polaritons.

Plasmonics with a twist: taming optical tornadoes on the nanoscale

http://arxiv.org/ftp/arxiv/papers/1405/1405.1657.pdf

Quote from axil

'Golden Balls' Cravens

http://www.infinite-energy.com/images/pdfs/NIWeekCravens.pdf

On excess heat

on the nuclear origin of the heat

Display More

Axil, did you understand the point in my e-mail immediately above yours?

Your comments do not address it. The "excess heat" is a difference of a few degrees between the temperature of two balls as given by thermocouples. I was highly interested in this demo and so looked at the paper in detail:

• There is no evidence for this excess heat other than the TC disparity.
• The TCs are sealed in the balls and never tested after the experiment
• The "conditioning" phase at high temperature is exactly what you'd expect would make H or D diffuse (at differing rates) into the TCs.
• The TC datasheet says that it is susceptible to errors due to reducing atmospheres and the specific device chosen is not roubustly encapsulated (and therefore can be contaminated by environmental chemicals).

That certainly does not prove these results are not excess heat. But, it provides a mundane mechanism for them not considered by Cravens in his paper. The demo was not meant to be high quality science, so anyone here treating it as such is being unfair to Cravens. If Cravens believes it is really working, he would expect that better instrumentation, and cross-checks, would turn this interesting curiosity into exciting and important evidence. My guess, since Cravens is no fool, is that he tried this, and got null results. The nature of LENR claims is that tiny changes in conditions can switch results on or off. Cravens therefore would not know that this demo is not working for real, especially if he was not aware of the TC drift due to environmental contamination issue. I'd expect he does not realise this issue as he does not mention it here and either show why it does not apply, or note it as a possible mechanism.

@Shane

I do my best! I tried on Abd's site recently only it went wrong.

Quote from axil

Regarding https://arxiv.org/pdf/1112.6276.pdf

This is one of my favored papers because it shows how surface plasmon polaritons produce fission in uranium by catalizing muons.

The creation of polaritons through the stimulation of gold nanoparticles demonstrates how the LENR reaction works in dusty plasma. Nanoparticles produce polaritons that in turn produce magnetic flux lines that intern produce proton decay that in turn produce muons that in turn produce the fission of uranium.

No fission happens when the gold nanoparticles are removed from the experiment.

It is the dust in the dusty plasma that produces the polaritons. The polaritons are created between the particles of dust.

Here is how particles produce polaritons.

Plasmonics with a twist: taming optical tornadoes on the nanoscale

http://arxiv.org/ftp/arxiv/papers/1405/1405.1657.pdf

Display More

So, just for Shane....

This paper is a good example of investigation into an alpha decay rate variation effect that most likely does occur, with good evidence.

However I see no obvious connection with LENR.

In this experiment the sample has TeraWatt (10^12W/cm^2) lasers shining on a sample. The idea (which Axil likes) is that surface resonances caused by the gold particles can locally amplify this already very high power e-m radiation by a factor of 10^4 or (the paper claims) even 10^6.

The resulting incredibly high e-m fields can induce alpha decay (not as axil says fission, though you would not want to rule that out), especially in large nuclei where the effect of the electric component of the field is larger than it would be in small nuclei.

In this paper the evidence for an affect on alpha decay is strong. The evidence for the field amplification being 10^4-10^6 as a mechanism is purely speculative, though as is referenced here plasmon amplification can have these very high Qs, so it is fair speculation. Note that as the authors caution, at ultra-high intensities there are many nonlinear affects not seen at lower intensity that would be expected to detune resonances, therefore whether SPPs could ever deliver very high Q at such high intensities as thus far unclear. I know of no work which addresses this question. The work here, together with a comprehensive theoretical analysis of the affect of electric field on alpha decay of these nuclei, might provide more evidence. The theory would be pretty difficult to compute, and again I don't know who has done this (anyone seen it?).

Since the decay scheme of
these nuclei is a sequence of both alpha- and beta-decays, one may conclude that laser exposure
of their solutions in presence of NPs alters both types of decay. The most probable mechanism of
laser acceleration of nuclear decays is the perturbation of electronic shells of unstable elements
in the field of intense laser wave [8]. This perturbation alters the inter-atomic field in the vicinity
of nuclei and thus alters its stability.

Strong dependence of the acceleration of alpha-decay on the peak power of laser
radiation in the medium should be related to the strength of fields of the laser wave. The natural
measure of the electrical field is its value inside the atom or ion. The electric field of laser wave
becomes comparable with inter-atomic field at intensity level of 1016 W/cm2. Possible
mechanism of laser-induced acceleration of alpha-decay can be illustrated as follows (Fig. 5).
Exposure of NPs to laser radiation leads to its amplification in the vicinity of NPs. If an ion of
Uranil is situated near the exposed nanoparticle, then strong electric field of the laser wave
disturbes its electronic shells. This perturbation causes the oscillations of the potential near its
equilibrium value with the frequency of laser radiation. So do the width and the hieght of the
potential barrier for tunneling alpha-particle. Since the probability of tunelling depends on the
barrier widt in an exponential way, so even its small variations can noticeably increase the rate of
alpha-decay

Only approximate estimations
of the peak power inside the solution with nanoparticles can be done. This is due to initiation of
various non-linear effects inside the liquid at intensity level 1011 – 1013 W/cm2 that may lead to defocusing of laser radiation.

This can be, for example, the dynamic Kerr effect. On the contrary,

self-focusing of the laser beam may lead to its filamentation and to the increase of laser intensity
in the medium. Finally, the presence of nanoparticles may alter the intensity level due to the
absorption of laser radiation via plasmon resonance of charge carriers in nanoparticles or in the
plasma produced around nanoparticles.

This stuff is interesting, and possibly of use. Whether of use or not it is worth understanding, especially the role of the gold particles in amplifying locally the field.

Could this mechanism underlie LENR? Possibly, but you would then expect that LENR effects were correlated with high intensity e-m fields from lasers. They are not noticeably so, though a few people including I believe Cravens have tried laser stimulation with no clear results.

It is certainly true that very very high intensity laser beams can induce fusion - though mostly attempts in this direction are from laser-induced compression, not direct e-m stimulation.

Fusion is a harder ask then alpha-decay to get from electric field perturbation of nuclei because you need two close together nuclei for it to happen, something that is made low probability by the electrostatic potential. Still, e-m fields can add to other shielding, distort the charge on nuclei, and therefore potentially affect fusion. I'd look very hard, and be very interested, if the experimental evidence for LENR was coherent with such a mechanism. However, the clearest evidence comes from electrolytic experiments where there is no high power coherent radiation.

e-m induced fusion (if it exists) is of course not really LENR since the powers from the lasers are very high. Still, if it were viable, with fusion energy much larger than laser energy in, it could be harnessed. the many people looking at novel ways to induce fusion have not yet found any such effect.

The "few evs paper"

@Bocjin

I find this one interesting too - but I've been holding off commenting because I don't understand what it claims yet. it is written in an annoyingly misleading way (no fault of the authors - these things happen very easily). It treats as central the amplification in fusion rate derived from screening, at looks at how this varies with nucleus kinetic energy (on which, with or without screening, fusion depends).

Here is where I've got to:

1. The screening effect U0 is experimentally claimed to be up to 100eV in metal lattices. Higher than expected from theory. But not high enough to lead to measurable fusion rates at any feasible temperatures.
2. The effect of this on fusion rate is simply to add U0 to the nucleus energy (whether that is thermal or something else) to obtain the effective energy used to determine fusion rate.
3. The amplification effect (of the screening on the fusion rate) is largest at a few eV. This is a silly way to look at it, and falls out of the equations. It is not very helpful because at these low energies, even though amplified by screening, fusion rates are so low as to be non-measurable.
4. There is a diagram, which it is claimed comes from the points above and relevant equations, that shows high fusion rates. This is what I don't understand since it is contradicted by the previous comments. I'd need to look at the math numerically, and then track back to its derivation, to see how this anomaly (in what the paper is saying) comes about. If somone else does this first I need not bother so let me know.

I'll give a better referenced and more considered view in a while (when I've time, I'm doing other stuff) if no-one else resolved this matter.

THH

@THHuxleynew,

Re the Simakin and Shafeev paper, note that photons from a A Nd:YAG laser (wavelength 1064 nm) do not have the keV or MeV that are needed to dislodge an alpha particle from a uranium-232 nucleus, or, presumably, to send the nucleus to a low-lying unstable state; they have 1.16 eV per photon. So something "low energy" is no doubt going on here if the results are as reported. (Presumably acceleration and scattering of uranium-232 atoms isn't the source of the decays.)

Here's why I think the Simakin and Shafeev paper might be relevant to LENR:

• The LENR heat-helium correlation makes a lot of sense if what is happening is the induced alpha decay of an alpha emitter.
• The evidence for the claim that the energy/4He ratio is close to the ~ 24 MeV/4He expected from dd fusion or effective equivalent (e.g., Miles) is sketchy and open to other interpretations, and ratio itself is not indisputably stable.
• There are numerous LENR researchers reporting transmutations of a kind one would expect as residue following alpha decay or fission.
• There are several LENR papers reporting prompt particles, including prompt alpha particles.

Although alpha decay and fission are slightly different processes, if alpha decay is being induced in a setup like that of Simakin and Shafeev, it would be unsurprising to discover that fission can also sometimes occur in such a context, as the two processes (alpha decay and fission) are both a function of the width of the Coulomb barrier and are very similar.

The mechanism proposed by Simakin and Shafeev may or may not be relevant or interesting. What is interesting is the experimental result. In this context, it is not too much of a stretch to wonder whether much of LENR results go back to such a process, induced in different contexts. Depending on how the laser interacts with the target, there may be other ways to accomplish the same thing without the laser.

Re the Simakin and Shafeev paper, note that photons from a A Nd:YAG laser (wavelength 1064 nm) do not have the keV or MeV that are needed to dislodge an alpha particle from a uranium-232 nucleus, or, presumably, to send the nucleus to a low-lying unstable state; they have 1.16 eV per photon. So something "low energy" is no doubt going on here if the results are as reported. (Presumably acceleration and scattering of uranium-232 atoms isn't the source of the decays.)

Well, my views align with those of the authors. The electric field will distort the nucleus and such distortion would be expected to alter alpha emission rate. AFAIK all they showed was a variation in the rate of alpha emission when this happened anyway. The nucleus is unstable so no extra energy needed to cause this emission.

Interestingly, where electric field is varying nuclear reaction rates it is not the energy per photon that is relevant, but the field magnitude. A larger field (more photons) means a larger effect, even though energy per photon is the same. The interaction here best understood with a field model not a particle model.

Note that the variation documented in the paper is an increase in the rate of alpha decay (the title of the paper is "Accelerated alpha-decay of 232U isotope ...").

Photons at these energies will not be interacting directly with the nucleus, so some other mechanism must be at play — perhaps EM fields as you and the authors speculate. But to step back and put the matter in simple terms, one significance of the paper is that in at least one case you have watts going into the system from a plug in the wall, and prompt particles with MeV of energy coming out of it as a result. Which is a lot like the results described in a certain category of LENR papers.

The topic is all the more interesting because it is an accepted truism in physics that you cannot alter decay rates more than a trivial amount, and especially strong decays. (Recall the response to my question on PhysicsForums.) This conclusion is at face value contradicted by the Simakin and Shafeev result. Either the doctrine about not being able to alter strong decay rates is off, or the Simakin and Shafeev study suffers from some kind of artifact.

Quote from Eric Walker

Note that the variation documented in the paper is an increase in the rate of alpha decay (the title of the paper is "Accelerated alpha-decay of 232U isotope ...").

I agree that it doesn't make sense to consider individual photons in this case, as they are unlikely to interact with the nucleus at those wavelengths/energies. But to step back and put the matter in simple terms, one significance of the paper is that in at least one case you have watts into the system from a plug in the wall and (additional) prompt particles with MeV of energy coming out of it. Which is a lot like the results described in a certain category of LENR papers.

The topic is all the more interesting because it is an accepted truism in physics that you cannot alter decay rates more than a trivial amount, and especially strong decays. (Recall the response to my question on PhysicsForums.) This conclusion is at face value contradicted by the Simakin and Shafeev result. Either the doctrine about not being able to alter strong decay rates is off, or the Simakin and Shafeev study suffers from some kind of artifact.

The examples of the engineering of LENR reactors that we know about indicate that the LENR reaction is only active when the KERR effect stimulus is on. One of the KERR effect stimuli is a laser beam. This activation mechanism is how the LENR reactor controls the operation of the LERN reaction. In other words, when the laser beam is on then the LENR reactor is active and when the laser beam is off then the LENR reactor is off. The reason for this behavior is because the lifetime of the SPP is just a few picoseconds. This short timeframe is the effective replacement timeframe of the SPP, that is, the time it takes one SPP to die and the next SPP to replace it. With this principle in mind, consider the results of this experiment.

I now reference a papers to show how the generation of SPPs on the surface of gold nanoparticles: a nanoplasmonic mechanism can change the half-life of U232 from 69 years to 6 microseconds when a laser beam is active and how this KERR effect stimulus can also initiate fission in thorium.

See references:

http://www.google.com/url?sa=t…TUA&bvm=bv.46471029,d.dmQ

Nothing happens when there is only a laser used with NO nanoparticles,

Form the article:

Quote

The effect of exposure of the solution to different laser sources is shown in Fig. 4. One

can see that the activity is decreased by a factor of 2 after 1 hour exposure to laser beam at intensity level of 10e12 - 10e13 W/cm2. It is reasonable to suggest that the alpha-decay proceeds during the laser pulse, while the spontaneous decrease of alpha-activity during exposure is negligible. This means that the activity drops down by a factor of 2 during 5 us, which is the total duration of all 150 ps laser pulses during exposure. In other words, the half-life of 232U in the laser field is 5 us instead of 69 years. About 10e10 nuclei of 232U decay during laser exposure.

Another infrared laser radiation with pulse duration of 350 ps affects the alpha-activity of the solution to lesser extent despite to much higher number of laser pulses.

In another experiment using a jet of high speed argon gas, the LENR ash produced by an electric arc at the instant of creation was radioactive, but by the time the ash traveled 100 cms in the high speed plasma, the ash was stable. LENR seems to speed up time for radioactive isotope decay.

See

http://www.newinflow.ru/pdf/Klimov_Poster.pdf

THHuxley

The screening effect U0 is experimentally claimed to be up to 100eV in metal lattices. Higher than expected from theory. But not high enough to lead to measurable fusion rates at any feasible temperatures.

Measured screening =Actually up to 800 eV for Palladium

1. THH"The amplification effect (of the screening on the fusion rate) is largest at a few eV. This is a silly way to look at it, and falls out of the equations. It is not very helpful because at these low energies, even though amplified by screening, fusion rates are so low as to be non-measurable. "

The final reactivities are of the order of 1x10(-10) cm3/s

In the atomic world cm3 is HUGE= 3.3x10 (22) water molecules.

So it is not surprising that the fusion rates are of the order of 10(13)persecond.

Considering that the energy per D-T fusion is 17 MEV

this is measurable as power~27W per cm3 of tightly packed nickel lattice ..providing deuterium diffusion is not the limiting factor

THH " I'd need to look at the math numerically, and then track back to its derivation, to see how this anomaly (in what the paper is saying) comes about. If someone else does this first I need not bother so let me know. "

I have looked at their bare ion(unscreened) reactivities on Fig1. These seem to tally with the final reactivities after multiplying by the enhancement factor

btw the Boltzmann temp equivlent of 4 eV (afew eVs) is 46,000 degrees K

http://www.colby.edu/chemistry/PChem/Hartree.html

Quote from bocijn

THHuxley

The screening effect U0 is experimentally claimed to be up to 100eV in metal lattices. Higher than expected from theory. But not high enough to lead to measurable fusion rates at any feasible temperatures.

Measured screening =Actually up to 800 eV for Palladium

295 +/-7	Zr 2008 high vacuum
494 +/-7	Zr 2008 v.high vacuum
800	Pd
394	Ni
520	Pt
251	Mo

1. THH"The amplification effect (of the screening on the fusion rate) is largest at a few eV. This is a silly way to look at it, and falls out of the equations. It is not very helpful because at these low energies, even though amplified by screening, fusion rates are so low as to be non-measurable. "

The final reactivities are of the order of 1x10(-10) cm3/s

In the atomic world cm3 is HUGE= 3.3x10 (22) water molecules.

So it is not surprising that the fusion rates are of the order of 10(13)persecond.

Considering that the energy per D-T fusion is 17 MEV

this is measurable as power~27W per cm3 of tightly packed nickel lattice ..providing deuterium diffusion is not the limiting factor

THH " I'd need to look at the math numerically, and then track back to its derivation, to see how this anomaly (in what the paper is saying) comes about. If someone else does this first I need not bother so let me know. "

I have looked at their bare ion(unscreened) reactivities on Fig1. These seem to tally with the final reactivities after multiplying by the enhancement factor

btw the Boltzmann temp equivlent of 4 eV (afew eVs) is 46,000 degrees K

http://www.colby.edu/chemistry/PChem/Hartree.html

Display More

Ok, so thanks for that. I'll look at this a bit more closely. It interests me. I'm commenting beow. Sorry if this sounds a bit didactic, it is not meant to be so, I'm happy to be corrected (with reason) on any of this. I find though that it is helpful to say clearly what I think and what I don't think, and why.

First. You are right about the high claimed screening potential. 800eV for Pd is indeed interesting because combined with a high D ion density (as may be found in vacancies) it corresponds to be possible measurable fusion rate.

Second. Unlike the vast amount of incoherent LENR data here, these screening energy measurements I find credible. It is worth saying why:

(1) Multiple groups have done the experiments at different times

(2) The results (at high deuteron energies) are checkable from the projectile energy/fusion result distribution which is characteristic of this process and nothing else. Therefore these results (which in any case are not marginal) are self checking within one experiment.

There seems to be a meme here that skeptical scientists prefer theory to experiment. That is a misreading. Skeptical scientists pay little attention to experimental results which are incoherent and not well validated, because they are more likely to be error than anything real. Even if they are anything real, without an idee fixee such as LENR (which could be seen as a theoretical bias), the incoherence means there is little traction and therefore not much point yet in speculating what the reality is. Where, as here, experimental results differ from theory but are coherent everyone looks at it with interest.

Third. I also agree that these results could just possibly resolve the LENR mystery by explaining some of the well-validated electrolysis results. Would that not be fascinating? It still has holes, because the lack of neutrons is not easily explained: the screening data on which this rests comes from measuring classic D-D fusion with expected branching ratio. While some different branching ratio cannot be ruled out in different circumstances it would be surprising. We don't see any sign of it in this data, and that is a problem for the LENR results that show excess heat from deuterated metals without the expected neutron flux,

Fourth. Given the above we need to look carefully at these experimental results. I'm giving a list of points that emerge so far (there may be others, also I may be misunderstanding this).

(a) The experimental data suffers from lower than real results where the surface oxidises. This is overcome by UHV experiments which do indeed show higher rates. To avoid this affect entirely it seems you need very good vacuum.

(b) The data here is collected at projectile energies that are measured in kEv. To a first approximation the effect of screening can be seen as an extra screening energy U0 added to the projectile energy to obtain the cross-section. However at low energies (relevant here) this approximation breaks down and the equivalent screening energy U0 reduces by a factor of nearly 2. (Figure 1 from [Czerski04]). The low energy extrapolation is necessarily theoretical, because the experimental data is obtained at much higher projectile energy (kEvs).

(c) Prados and Estevez reference the earlier work looking at this, and noting the energy-dependence of screening factor, but do not take up the issue of energy-dependence themselves. They use the experimentally-determined values without any correction. So I don't trust this. But, equally, it is clear that some of the earlier estimates (at high energies) are too low due to oxidation etc effects, so we have an initial value higher than used by those earlier authors (who, to be fair, were aware of this possible issue).

(d) We cannot be confident what correction there should be for very low projectile energies, since it is a theoretical correction and the theoretical values at high energies seem to low according to experiment. Still, we have no reason to think the real correction should be lower than that predicted by vanilla theory rather than higher.

(e) One comment worth remembering here is that when "theory is wrong" that is often not actually true. The theory here is too complex to get more than approximate numerical results, and all we are saying is that the assumptions used to make these are incorrect - and that uncertainty is well understood by those doing the calculations. That is, in this case, expected, since the real situation is very complex. It is better to think of the vanilla theoretical calculations as giving an first-pass approximation (and for example correctly predicting most of the dependence between reaction rate and projectile energy). Further work then makes various corrections to this value.

These higher than expected screening values make me less skeptical overall about LENR effects having some nuclear mechanism. I'm still very skeptical, because the experimental data remains incoherent. As always, my lack of affection for LENR theory is the lack of coherent experimental evidence that supports it.

If this does result in measurable fusion rates it would be useful to compare deuterium and D/T mixture rates, since the D/T fusion should have the same screening but lower activation energy and therefore higher reaction rates. Also, the mechanism for the higher screening is not yet clear, and elucidating it looks a good investigation to me.

I'll say more later, maybe.

EDIT - see my later post which almost completely invalidates this!

When we're talking about dd fusion, THH has made the point about the dd branching ratios, which include copious neutrons. In addition, tritium and 3He are byproducts, and little 4He is made.

Also worth pointing out: when we're talking about normal dd fusion, the context is scattering of some kind, in this case, d with d. In a metal lattice, the energies of any atoms or molecules will be in the sub-eV. At 4 eV you have the equivalent of a powerful chemical explosion. 100 eV are not normally attained outside of the context of something like ion bombardment.

Conclusion when you don't see neutrons and tritium as byproducts: you don't have typical (dd) fusion. By contrast, if you see neutrons and tritium in equal amounts in your experiment, and correlated with the input, what you're seeing is typical dd fusion, and whatever you are studying is unlikely to explain LENR PdD findings.

Conclusion when you have an electrolysis setup: you don't have appreciable numbers of atoms, molecules or ions moving at greater than sub-eV to 4 eV. By contrast, if you are studying a system in which there are atoms, molecules or ions in the range of 100 eV or more, whatever you are studying is unlikely to explain LENR PdD (electrolytic) findings.

Overall conclusion: the enhanced screening at low energies is very interesting, but the experiment will not be very effective in explaining results seen in the PdD electrolytic system, where neutrons are almost not seen above background, and 4He is seen to be correlated with heat, and 3He is something of a wildcard. What it might do is hint at new physics at work in the LENR case, and so be indirectly relevant.

OK, I have a problem with Prados-Estevez et al. Nuclear Instruments and Methods in Physics Research B 407 (2017) 67–72

Their extraordinary theoretical results rest on multiplication of the reactivity enhancement factor from screening and the reaction probability at low energies.

These are taken from equations (6) and (15):

These two equations are inconsistent. If, indeed, they were correct, the screening enhancement factor will dominate the reactivity factor at low enough temperature since the reactivity scales as exp[ -(KEg/kT)^1/3] and the enhancement scales as exp(KEg/kT), where K = 27/4 and Eg is the activation energy, T the temperature, k the Boltzmann constant.

That cannot be true, because as stated in this paper the enhancement effect must be equivalent to altering Eg by a (roughly) fixed screening energy U0. Obviously the eqn (15) exponent must have the cube root as well as eqn (6). Otherwise at low enough temperatures any small amount of screening would result in high nuclear reaction rates. This would apply universally.

This is a major (glaring) error in the paper which invalidates its results. I said originally that the Fig 2 graphs looked quite wrong when compared with the early analysis. We can now see why, they are based on this erroneous eqn (15) which makes the log enhancement factor to be the 3X larger than it really is.

I apologise for being so slow on the uptake about this. it is pretty glaring and had I read the paper more carefully (linearly) I would have caught it. But, reading papers so carefully takes a good deal of time...

Should I be incorrect here I'll happily listen to correction, but I do not think that can happen given the work I've posted.

THH Huxley " These two equations are inconsistent"

They appear inconsistent to you because they refer to different things

My interpretation is that Equation 6 yields the unscreened reactivities (UR)

which are graphed in Fig 1.

Equation 14,15 multiplies these UR by the screening factor to give the screened reactivities (SR) as shown in Fig 2.

I do not think that 3 research physicists working collaboratively on a research paper for one year

are going to make an error that can be 'debugged' up in 1hour by a pharmacist like me or any other layman scientist.