In reply to Eric Walker's message of Fri, 4 Dec 2015 18:12:56 -0600: Hi Eric, [snip]
Ok, I had that completely wrong. I forgot that He4 itself doesn't have as high a binding energy per nucleon as most of the other elements. In short it should fuse with almost anything stable, provided that the Coulomb barrier can be overcome. >On Fri, Dec 4, 2015 at 3:07 PM, <[email protected]> wrote: > >I guess there are some exceptions. :) >> > >For exothermic 4He + Pd reactions with 1-3 daughters which also occur in >nature, I get a count of 269 reactions. If one removes the limitation on >unstable daughters, I get a count of 4556 reactions. > >4He + 102Pd => 26Mg + 80Kr + 8602 keV >4He + 106Pd => 22Ne + 88Sr + 8464 keV >4He + 104Pd => 4He + 30Si + 74Ge + 8460 keV > >(Some of the reactions spit a 4He back out.) > >However try this for the reactions that Iwamura reported. >> > >To get from cesium to praseodymium, we have: > >4He + 133Cs => gamma + 137La + 1495 keV >4He + 137La => gamma + 141Pr + 1300 keV > >To get from strontium to molybdenum, we have: > >4He + 88Sr => gamma + 92Zr + 2963 keV >4He + 92Zr => gamma + 96Mo + 2759 keV > >The case of barium to samarium does appear to be endothermic; e.g., > >4He + 137Ba => gamma + 141Ce + 139 keV >4He + 141Ce => gamma + 145Nd + -1579 keV >4He + 145Nd => gamma + 149Sm + -1872 keV > >Iwamura and the other authors had trouble confirming samarium when they >started with 137Ba, although they thought it was probable. It makes sense >that this chain would have been attenuated due to the endothermic steps. >But if the result was in fact real, it also suggests that the alphas are >travelling with ~ 3-9 MeV of energy. :) > >The actual chains would have been more complex in the case of barium >because some of the intermediate steps are unstable. But a more complete >analysis shows that several paths that diverge will eventually reconverge >on samarium. > >Eric Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
