I was wrong about Rossi, but what I fear most is that I might be partly right

Quote from Mary Yugo

Complete nonsense. The main cost of hot fusion projects is the complex and giant hardware and supporting infrastructure... .. . . .... . ... ...... ... ... ..... .. .. ... ...

When will You hold your first lecture? Location: University of confusison, money-land USA ? OK ?

Quote from Argon

Hi Walker. Unfortunately no non-speculative and especially I cannot recall was he declared quelified HVAC or just highly educated wit lots of experience in nuclear industry with good amount of experience in similar power measurement tasks.

Note that there's another "Walker" on this forum, whose positions are pretty far from mine. I usually go by "Eric" or "Eric Walker".

Quote from Hermes

One remark I would make is that there are very few nuclear reactions which produce alphas at 2 MeV. This is rather good news as it means we may be able to identify their origin so much better. (For example all known alpha decays are ruled out).

I've seen LENR studies reporting alpha particles with greater than 2 MeV energy.

Assume for the moment, though, that there are generally alphas with an upper bound of 2 MeV in LENR experiments in which energetic alphas are seen. There are plenty of isotopes for which the decay of an alpha would be exothermic but less than 2 MeV. The decay rate is proportional to the energy of the decay, and these isotopes are usually observationally stable (I assume, without taking time to check). But are they really stable outside of the context of LENR, or do they simply have undetectable decay rates, with LENR somehow managing to interfere with them and speed them up? (Following Paradigmnoia's careful terminology, such decays would be "reactions" rather than "decays'".)

Quote from Peter Ekstrom

No, the Q-value for d+d-->4He is 23846 keV. For GeV energies you need annihilation with anti-nucleons

I was referring to the heat / helium ratio not the energies of individual reactions. Taking into account the expected rates of all 3 branches of d-d fusion and the energies of each, you can verify my estimate.

Quote from Eric Walker

I've seen LENR studies reporting alpha particles with greater than 2 MeV energy.

Assume for the moment, though, that there are generally alphas with an upper bound of 2 MeV in LENR experiments in which energetic alphas are seen. There are plenty of isotopes for which the decay of an alpha would be exothermic but less than 2 MeV. The decay rate is proportional to the energy of the decay, and these isotopes are usually observationally stable

Of course LENR is complicated and the reactions which take place depend on the fuels available. I think most of the fast alpha studies have been in deuterated systems, but Piantelli works with natural hydrogen.

The only fast low energy alpha decay is that of Be8 at 92 keV. Much heavier than this and alpha decay becomes endothermic. The lightest natural isotope which in theory could alpha decay is 142Ce at 1.3 MeV. But the decay is so slow it will never be observed. The reason is the Gamow factor (Coulomb barrier). There are a few alpha radio-active isotopes decaying in the 2-3 MeV range but we can exclude them because the have very long half lives. For example unnatural 146Sm decays with 2.5 MeV. So I think that we must look elsewhere than conventional decay to explain 2 MeV alphas.

Quote from Alan Smith

in the energy range 660.0 - 663.0 keV in order to find a possible nucleus responsible for the emission.

Well I repeated this analysis using PCNUDAT software. In the gamma energy range 660-663 keV I find 6 isotopes, 50Mn, 66Ge, 67Ge, ... In any case the measured gammas are close to background levels and consequently must represent some secondary or tertiary reaction. It's all a bit inconclusive.

Quote from Alan Smith

You found pretty much what is reported in that quote. So how is that inconclusive? Focardi et al say it is 'hard to justify'- but that is not quite the same thing.

"Inconclusive" means you cannot draw conclusions. What scientific information on do these gammas tell us? What did you conclude? I suppose we could say that something nuclear is going on but that is so vague as to be useless. Now if they had measured a million counts per second .....

@Hermes
I was pointing out that although the alpha decay rates of medium and heavy isotopes for which alpha decay is exothermic are low to negligible, this might be the variable that changes in LENR. I.e. the (alpha) decay rates might increase across the board. So alpha decay can NOT be ruled out.

Also, the 2 MeV upper bound is not a clear restriction that one must adhere to, as there are reports of aphas with more energy than that.

Quote from Mary Yugo

But I can tell you that sustained, replicable power production by LENR at the kilowatt level has never been proven to exist. Power production at high level by hot fusion is a reality.

Here is are two consecutive examples of two related fundamental errors in assessing energy production. "Kilowatt level" has to be related to power or energy density to have meaning here. As one example, Mitchell Swartz has demonstrated power levels on density and/or volumetric basis that would easily equate to kilowatts per kilogram of reactor. That is he has shown excess energy per gram of reacting device that are to my mind impressive.

Our Sun, to put a relative metric on it, is distinctly unimpressive, that is in the center of the core, energy production density at best on the order of 275 watts per cubic meter. At the core the density is reportedly 150 g / cm^3, thus one cubic meter weighs 150,000 kg, and the core extends outward to about 25% of the distance to the Sun's surface, the density at the outer edge of core is around 20 g / cm^3. Power volume at the center by one estimate: 17 watts per cubic meter. Power density? Generously allowing 275 watts per cubic meter for the whole core (it's not that high) and assuming a linear density function (also only approximate) we would get a power density of 3.2 mW per kilogram or 3.2 microwatts per gram.

LENR often far exceeds this as is pointed out in the nice review at:

http://coldfusionnow.org/power…e-sun-we-already-have-it/

Quote from Eric Walker

although the alpha decay rates of medium and heavy isotopes for which alpha decay is exothermic are low to negligible, this might be the variable that changes in LENR.

This supposition is not entirely unreasonable. After all if theoreticians can invoke mechanisms to reduce the Coulomb barrier for fusion, why not for fission (alpha emission) too? But I am pessimistic. To facilitate fusion only 1 keV or so might be required. (e.g. muon catalysed fusion). But to accellerate alpha decay to timescales comparable with CMNS experiments (weeks), many MeV would be required. Furthermore nickel and palladium cannot emit alphas exothermically. So whilst I like your original thinking, I am rather doubtful if it is correct. Keep up the good work!

Quote from Hermes

But to accellerate alpha decay to timescales comparable with CMNS experiments (weeks), many MeV would be required.

Or momentary transients of considerable electron screening by, e.g., a rush of electric current passing through the nuclear volume for a brief moment. It seems not only plausible that this kind of thing happens, but likely.

Quote from Hermes

Furthermore nickel and palladium cannot emit alphas exothermically.

No recent replication experiments using pure nickel have been shown unequivocally to produce excess heat, with only anecdote here and there to go from; perhaps there are some impurities that are important. But consider another possibility: electron capture. This is a weak interaction process, so quite different from that of alpha decay. But if there are transients of high current passing through the nuclear volume from time to time, I would be surprised if the weak interaction did not come into play.

In the case of palladium, fission proper seems more likely than alpha decay, by way of the same general mechanism of electron screening.

Brillouin — my own opinion, 80 percent anecdote (say); we have some kind of sign-off of by McKubre, but it's not clear what he did or assessed or approved of. If Brillouin are talking about electron capture now, I wonder whether this is a new thing; I recall the theory Godes espoused sometime back as being word salad. But from day 1 I have been interested in knowing whether their experimental results are good.

Quote from Alan Smith

This paper by Focardi et al shows that when it comes to particles, you don't always get what you expect.

newenergytimes.com/v2/library/…ctromagneticRadiation.pdf

Yeas Alan: This paper did confirm the 1.44MeV radiation of the intermediate HH-> D fusion...