In reply to Stephen A. Lawrence's message of Fri, 21 Jan 2011 14:35:44 -0500: Hi, [snip] >In >particular, there should probably be a really large fraction of Ni^59 >present (31 neutrons), with a 75 ky half-life, and I'd think that would >make the sample pretty "hot". Or so it seems; I haven't done the >calculations to back up the intuition. [snip] Ni-59 decays almost completely by electron capture directly to the ground state (hence no gammas), and all the energy is take by the neutrino, so this decay is not detectable (however about 1/25000 decays are via positron). See http://atom.kaeri.re.kr/cgi-bin/decay?Ni-59%20EC
Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/Project.html