Robin, Another slightly modified explanation would be dense hydrogen in the role of virtual neutron. If thermal neutrons were involved, we would likely see activation elsewhere.
Jones > A slightly modified explanation:- The high binding energy makes Ni62 more likely than other nuclei to capture a neutron. Ni62 + n => Ni63 which then decays to Cu63 over time. A supernova explosion may well release a massive amount of energy, but I doubt the temperature is high enough for Ni62 + p to be significant. OTOH, they are characterized by massive neutron formation, so the reaction above may be more likely. >> the % abundance of Ni-62 which we find in nature is surprisingly low at only >> 3.6% of all nickel. This abundance should be much higher given its inherent >> nuclear stability (binding energy). The solution to that mystery may help >> explain something vital about LENR.

