I think we can eliminate 2 kind of impossible reaction : - those involving free neutrons that would be thermalized even rarely, and detected - those not geometrically balanced which would creat a gamma tha would be detected.
geometry is the key because of CoM. probably the electron is too, but that is not sure... 2014-10-14 7:22 GMT+02:00 <[email protected]>: > Hi, > > (This email best viewed with a fixed width font). > > Prime candidates are even numbered elements with an odd number of > neutrons. This > is because subtracting or adding a neutron produces an even-even nucleus, > and > these tend to be stable. > > The reactions that yield the most energy would use a neutron source where > the > neutron is only bound loosely. Here is a table with some isotopes and the > binding energy of the odd neutron (the lower the binding energy, the > easier it > is to remove):- > > Isotope Energy (MeV) ppm of the element in the Earth's crust > D 2.2 ! > Li7 7.25 13 ! > Be9 1.573 1.5 > C13 4.946 200 > Mg25 7.331 32000 ! > Si29 8.474 267700 ! > Ca43 7.933 52900 ! > Ti47 8.88 5400 ! > Ti49 8.142 " ! > Ge73 6.783 1.6 > Se77 7.419 0.05 > Sr87 8.428 260 > Zr91 7.194 100 > Mo95 7.369 1 > Mo97 6.821 " > Pd105 7.094 0.001 > Cd111 6.976 0.098 > Sn117 6.943 2.5 > Sn119 6.483 " > Ba135 6.973 250 > Ba137 6.90 " > > The most useful isotopes are likely to be those of low atomic number, high > abundance, and reasonably large isotopic percentage of the element in > question. > > These have been indicated with an "!". > > In particular, Mg25 may be an opportunity that has been missed so far. It > is > interesting both because of it's abundance, and because of the neutron > binding > energy comparable to that of Lithium. > > Possible interesting reaction:- > > 25Mg + 25Mg => 26Mg + 24Mg + 3.763 MeV > > Furthermore the energy is divided over two nuclei of almost equal mass, > hence > each gets about half (1.9 MeV), so this could be a very clean reaction. > > > Regards, > > Robin van Spaandonk > > http://rvanspaa.freehostia.com/project.html > >
