For those of us who are rational about experimental results, this is bad news since it is not news that LENR is a real phenomenon -- but large scale tritium production -- a radioactive product renders the process subject to government control hence political control.
On Fri, Jun 14, 2013 at 11:55 PM, Eric Walker <eric.wal...@gmail.com> wrote: > I just looked into some details concerning the scenario presented in slide > 9 of Michael McKubre's recent presentation in Brussels to get a sense of > what might be causing the tritium they were seeing. > > The slide summarizes an Arata/Zhang replication. In their replication, > they saw excess heat and, apparently, primarily tritium. This is unusual, > because when tritium has been present in many experiments, it has usually > been found only in small amounts, suggesting that it is the result of some > kind of side reaction. But the slide indicates that they saw 2-5 * 10^15 > atoms. If you consider that 1 W excess heat from the generation of 4He > from d+d (however this happens) will yield on the order of 10^11 atoms, it > is apparent that 10^15 atoms is a lot of tritium. Presumably the > experiment ran for a while, but nonetheless one gets the impression that > the tritium is more than simply the result of some side reaction, and it > looks like the main daughter in this case. > > The possibility of excess heat arising primarily from tritium generation > poses some interesting questions: What were some candidate exothermic > reactions that might produce the tritium? Is some kind of neutron capture > required to explain the result? What else can be gleaned from the slide? > > For the quick analysis that follows, here are relevant details: > > - The experiment involved palladium black and LiOD electrolyte in an > electrolytic setup. > - They saw excess heat from LiOD but not LiOH. > - They saw no 4He. > - They saw no 3He above what can be expected from the decay of > tritium. This suggests that the 3He was not a daughter product of whatever > reaction was causing the heat. > - The 3He they saw diffused from a source within the hollow cathode, > which had the palladium black within in it. I think palladium black is in > the form of powder. > > After looking at a number of reactions, I found only two exothermic > reactions that produce tritium with precursors that would have been present: > > - 6Li + d → t + 5Li + 594 keV > - > - 3He + n → p + t + 1.27 MeV > > I saw no other reactions involving stable isotopes of H, Li, O, or Pd that > were exothermic, although it is possible the heat was generated by a > reaction I missed or by one involving a different element. At a minimum it > seems that deuterium was needed, because they saw excess heat with LiOD and > not LiOH. > > Assuming for the moment that the reaction was one of these two, neutron > capture cannot be ruled out, but neither is it necessary. If the 3He > really was a byproduct of tritium decay, then neutron capture would appear > to be unlikely as the primary source of heat in this instance, leaving the > 6Li+d reaction. Another reason the 3He+n reaction seems unlikely as the > primary source of heat is that it does not involve deuterium. > > Since 6Li is 7 percent of naturally occurring lithium, the amount of if > that will have been present in the electrolyte is non-negligible. But it's > not clear that it would make it into the hollow cathode, where the tritium > diffused from; perhaps it was able to enter the cathode through a crack in > a ligation that was used to seal in the palladium black. Another > possibility is that tritium was generated at the exterior of the cathode > and then migrated through the cathode into the center, where palladium > black was. In this case the reaction would have been in the electrolyte or > at the interface between the exterior of the cathode and the electrolyte. > If this is what happened, it is not clear what would have been driving the > 6Li(d,t)5Li reaction. Perhaps there were d's shooting out into the > electrolyte sufficiently fast for this purpose. I am not sure what the > cross section for this reaction is, which could tell us how fast the d's > would need to be going. > > To summarize some interesting details: > > - The possibility of tritium as the main daughter product giving rise > to excess heat is unusual and is worth thinking about. > - It looks like the tritium and excess heat could be arising in this > case from reactions with the electrolyte that involve lithium and > deuterium. > - Alternatively, neutrons from an unknown source could be causing the > tritium and excess heat by way of 3He(n,p)t reactions, but if that is the > case, you would need a way to get neutrons from the presence of LiOD and > not LiOH, and you would need the presence of 3He prior to that of the > tritium. > - If the lithium in the electrolyte is involved, it seems like you > would need fast particles to keep things going; fast enough, anyway, to > make the 6Li(d,t)5Li reaction a likelihood. > > I would be interested in seeing the paper that the slide is based off of. > Has anyone seen it? > > Eric > >
