Quote from AbdThanks. There is work that created helium above ambient. A clean example is Apicella et al, 2005. Three cells. Ambient helium was not excluded, so what they were measuring was elevation above ambient. (Krivit completely misunderstood this in attacking Violante). The helium measurements showed correlation. One of these included anodic stripping and produced a result very close to the theoretical value, it was actually "on the money," but ... this cell had the lowest heat and lowest helium so the error bars are large (I think about 20%). The others did not have anodic stripping and showed roughly, off the top of my head, about 60% helium release on the assumption of 24 MeV/4He. This experiment did not generate all that much heat, but I think it had a very small headspace, so a little helium raised the levels substantially.Most experiments had much more headspace, so raising helium levels above ambient would be difficult.It is not necessary, in fact. Key is the correlation across many experiments. Leakage is extremely unlikely to somehow create the 23.8 MeV/4He numbers. Yes, ambient helium should always be measured, but Miles was able to show that leakage was not experimentally significant. His lab, in fact, had almost double the natural helium, from what else was going on there. It's an obvious place to consider possible artifacts. Miles handled this with controls, for the most part. Leakage should not depend on the presence or absence of the excess energy. (And, no, experiments with excess heat are not significantly hotter than those with it, and in some cases, they are at the same temperature by design.)
I'll check Apicella et al and get back to you.
on your other comments - you I think have not excluded the "data selection" argument, and have perhaps misunderstood the "leakage vs excess heat mundane correlation argument.
Data selection: yes this can generate roughly the expected results. We'd need a much more subtle analysis to determine whether the precise figure was coincidental, and also be careful about cherry picking etc in getting it. We could explore further that assertion if you wish.
Excess heat vs He correlation. The issue is that artifactual excess heat for a given cell will in most experiments correlate precisely with time, as will artifactual He content due to leakage if ambient level is high enough. These two correlations lead to a beautifully precise (for one cell) He/excess heat correlation.
So any one experiment can be considered fully (which I've promissed to do with Apicella if you stay to discuss it - it will take maybe 24 hours because I've other commitments. Trying to amalgamate results across different experiments is problematic because of potential selection artifacts. I think you'd need to state precisely how you were doing this amalgamation, and we could then check all of the rather complex issues.
More generally, all of this analysis is sort of unnecessary - because a new good experiment could possibly provide better data than all previous.