On Sat, Nov 28, 2015 at 2:44 PM, <[email protected]> wrote: >At any rate, in this case, we > >seem to have an example of a single environmental factor that would > >increase the rate alpha emission and increase the alpha capture cross > >section. > > ...and exactly how would it do the latter?
It would increase the alpha-capture cross section by screening the Coulomb repulsion, allowing a more direct approach by the incident prompt alpha particle. In this thinking, tunnelling across the barrier into a nucleus for which it would be energetically favorable to capture an alpha particle (i.e., many lighter ones) becomes more likely if there is less Coulomb repulsion to deflect the alpha out of the way on its approach. I don't think the approach even has to be fully on-center. Note that simple fusion is not necessarily what is needed; a compound nucleus that decays briefly after the capture is also good for producing heat. I would think that it would actually > slow down fusion, since it would effectively reduce the energy of the > (positively charged) source particle. By a small amount, I would imagine. An alpha particle emitted from a typical alpha-emitter is going to have 4-9 MeV. Eric
