Eric Walker <[email protected]> wrote:
> Of course, helium is not hydrogen, but still, it does indicate there is >> trapped gas. >> > > For palladium and deuterium, where we know 4He is produced, 4He is > immobile in bulk palladium, while deuterium will escape over time. The 4He > gets stuck in a way that H or D does not, as I remember. > Yeah. It is well established that He gets "stuck" more easily. But I do not think the difference is so dramatic that H or D will all come out but the He will remain completely stuck. The methods they use to unstick it before taking an inventory are the same as the methods used to drive the H or D out. I have read various papers about this and discussed it but I do not recall which papers. > An implication is that to measure the full amount of 4He that has been > produced in a PdD system, it is advisable to melt down a cathode to get at > the 4He trapped in the bulk. > That is the extreme method! The point I am trying to make is that for a short experiment with bulk metal, that produces heat for a few weeks, probably most of the D that reacts was in the cathode to start with. Probably not much more comes from the electrolyte. So it is a reasonable approximation to the used the moles of metal and assume there are that many moles of D. Okay, for all I know it could be off by a factor of 5 or 10 but that still isn't many moles. They say that loading is never uniform, and bulk metal never loads 100%, so 1 mol gas per 1 mol metal is an exaggeration. (So "they" say.) Even when loading is measured at 100% that is because the 4 probes are hitting loaded areas between them, I think. Probably the lost gas method would show less than 100%. I would not know about nanoparticles. - Jed
