In reply to Jones Beene's message of Thu, 24 Mar 2016 16:38:02 -0700: Hi Jones,
Perhaps I should have been more explicit. By stimulate I really meant "catalyze". In short some form of stimulus where no external energy is actually added, but which speeds up a reaction. Stimulus as you apparently mean it, i.e. a reaction resulting from the addition of energy in some form to the nucleus is of course always possible. Note however that 64Ni has close to maximal binding energy per nucleon, so you need to add quite a lot to get it to change. >----Original Message----- >From: [email protected] > >> Stimulated "decay" is not a possibility. You can't "stimulate" a reaction >that's isn't going to happen all by itself anyway over a long enough period, >and 64Ni doesn't decay. It's quite stable. > >Hi, Robin > >No, that's technically not correct on two counts, although nickel in general >is high on the list of presumed stability since it has a magic number of >protons. There is no intrinsic or absolute property of "stability," since it >is purely observational - and as we know, many nickel isotopes do decay, >despite the magic - notably 63Ni which is lighter than 64Ni. > >There are many nuclides which are now known to be slightlyradioactive, but >forty years were called stable because they have extremely long half-lives >and were not observed to decay. My old Oxford reference book has a number of >errors, due to recent observation. > >Secondly, stimulated decay can be the product of a strong stimulant, so to >speak, such as a cosmic ray neutrino, muon etc. That was the original >context. > >Of course any sufficiently strong stimulant can give the identical >appearance of decay, and to quibble about the semantics of whether it is a >reaction or a decay is of no help- since stability is an observed property. > Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
