I doubt that the mass spec readings would have had such a peak at 64 given the low concentration of Zn reported.
Bob Cook From: Eric Walker Sent: Monday, March 28, 2016 7:24 PM To: [email protected] Subject: Re: [Vo]: Kamacite and natural fractionation of heavy nickel On Mon, Mar 28, 2016 at 9:10 PM, Jones Beene <[email protected]> wrote: Obviously, the next questions are something like this: was the depletion of the zinc-64 (compared to the starting level) due to its slight inherent radioactivity, and was the decay vastly accelerated? If so, then we must accept that accelerated beta decay can provide excess heat and possibly avoid detection. Other mechanisms are possible but 64Zn has an extremely long half-life, yet it is known to beta decay. This thought occurred to me as well. The decay I considered was a double-electron capture to 64Ni. The difficulty with this and other weak-interaction decay modes is that the number of nucleons does not change. By contrast, what was reported was a decrease in the 64 mass peak by nearly half. This observation is what lead to an earlier comment of mine that there might be a large experimental uncertainty. Or there's something changing the number of nucleons for 64Zn and/or 64Ni, in which case I personally have no conjecture to propose. Eric
