On Tue, Mar 29, 2016 at 9:06 AM, Jones Beene <jone...@pacbell.net> wrote:
If there is a nuclear decay reaction responsible for the thermal anomaly, > then 64Cu is the “swing element” in the triad - and has a half-life of > about 12 hours. It can beta decay by positron emission to 64Ni, or more > often by negative beta decay to 64Zn, but mostly by electron capture to > 64Ni. There is little residual radioactivity. The positron emission should > be detected. Since there is no evidence of that well-known signature – > doubt is cast on the mechanism being nuclear. Without further weighing in on the question of whether zinc was actually present, note that (double) electron capture would produce only soft x-rays, which are easily attenuated. Electron capture competes with positron emission, and in this case the neutrino has a characteristic energy, carrying away the majority of the energy of the decay. There is an Auger cascade that follows, as the electronic structure adjusts to the new nucleus, which is the source of the soft x-rays. It is possible that a suitable environment could stimulate electron capture without leading to competing positron emission, e.g., through a surplus of electrons passing through the nucleus. Eric
