What I don’t understand is if this is possible: 1 - 4He + 4He → 8Be(-93.7kEV) 2 - Be8 -> 2He4(18.074 MeV)
If this reaction is possible, and if this is what recombination is, where does the 18 MeV come from. Axil On Sun, Aug 19, 2012 at 3:31 PM, Axil Axil <janap...@gmail.com> wrote: > When the electrons fall back into their ground states we can comfortably > assert that the photons emitted will equal the energy input. > > This is a bad assumption. > > If two helium atoms fuse about 18 MeV is produced along with a positron > and a neutrino. I do not understand this reaction. Maybe someone can help. > > http://everything2.com/title/proton-proton+chain > > In the PPIII stellar fusion reaction, Steps 1 through 3 can be replaced > by the first half of the triple alpha stellar fusion process > > http://en.wikipedia.org/wiki/Triple-alpha_process > > Explicitly > > 1 - 4He + 4He → 8Be(-93.7kEV) > > 2 – 8Be + proton → B8 (0.135 MeV) - other possible reactions involver > electron and hydrogen capture. > > 3 - B8 -> Be8 + positron + neutrino (followed by spontaneous decay...) > > 4 - Be8 -> 2He4(18.074 MeV) > > We start out with two helium atoms and we end up with two helium atoms but > about 19MeV of additional energy is produced. > > Where does this energy come from? > > J. Rohner says that he stops the triple alpha stellar fusion process > before a third helium atom is fused. He calls this process recombination as > the Be8 fissions back to two helium atoms. > > > Cheers: Axil > > > On Sun, Aug 19, 2012 at 1:44 PM, James Bowery <jabow...@gmail.com> wrote: > >> Let's say you've got a xenon atom. It likes to absorb energy and emit >> photons. You know, xenon lamps etc. >> >> OK, so lets ask a real simple question: >> >> When a tube filled with xenon gas has some energy pumped into it and the >> electrons go to higher orbitals -- yes this happens for a very short period >> of time before photons are emitted but let's talk about just the short >> period of time. The diameter of the atoms presumably increases. Does the >> gas pressure increase during that interval? >> >> Now lets say that the energy is sufficient to actually strip the >> electrons away and form an ionized gas for a short interval. Does the >> ionized gas pressure increase during that interval? >> >> Now lets talk about really-simple magnetic confinement (say a magnetic >> mirror <http://en.wikipedia.org/wiki/Magnetic_mirror> type bottle) used >> in conjunction with a solid tube so that the non-conducting (because >> non-ionized) gas phase is confined by the solid tube and the conducting >> (because) ionized gas phase is confined by the magnetic bottle: >> >> When the electrons fall back into their ground states we can comfortably >> assert that the photons emitted will equal the energy input. However, what >> if the plasma has expanded during the high pressure phase, ie: done work >> against the magnetic confinement (like, oh, I don't know, generating an >> electrical power spike in a conductor associated with the magnetic field). >> Does that mean the "free" electrons of the plasma no longer want to return >> to their ground states and give up exactly the same amount of energy that >> they would have in the absence of having done work? If not, where did the >> electrons go and where do the xenon atoms get electrons to substitute for >> them? >> > >
