I don't think I have ever seen this description of the plasma collision of d-d. I was reading about the nature of the strong force and trying to understand the plasma fusion branches when I developed this mental picture.
I don't really understand what you mean by "strong Coulomb field in the background". In plasma fusion, I envision the Coulomb field primarily coming from repulsion from the two protons as they approach each other. In this case I envision the center of mass as being between the n and p, but the Coulombic repulsion is between the 2 protons which sets the ion in rotation to try and put the protons on the outside - away from the approaching collision. The speed of approach is so high that the ion has very little time to change its rotation, so it is probably only a small phase change and only a small effect in enhancing the d(d,p)t branch. I think of the strong force, as I said as being an effect that is extremely strong over only a fraction of a diameter of the nucleon. If you think of the nucleon being stuck on contact, but not in its final, minimal energy location within the nucleus, the acceleration on that nucleon is immense due to the extreme force applied by the strong force and light weight of the nucleon. This causes the nucleon to move extremely quickly to its final position, where it would need to stop with high acceleration as well. This makes me wonder about Bremsstrahlung in this case, only the transit time for the stuck nucleon from starting to final position may be much shorter than the period of an x-ray. Bob On Sat, Jul 26, 2014 at 10:53 AM, Eric Walker <[email protected]> wrote: > On Fri, Jul 25, 2014 at 8:00 AM, Bob Higgins <[email protected]> > wrote: > > When you speak of the plasma fusion output channels, I like to think of it >> in a Bohr-sian way. Presuming plasma, you have isolated deuterium nuclei, >> with each nucleus spinning around random vectors. When a pair approaches >> with a trajectory alignment that the collision will result in fusion, the >> relative rotation between the nuclei is still random. >> > > After thinking about this more, I kind of like your description for the > three dd branches. Is it something you heard or read about somewhere, or > just what made sense to you? > > The strong force is like fly paper - it is so short range (fraction of a >> nucleon diameter), you have to essentially "touch" before sticking. So you >> end up with 3 possibilities of this close approach: 1) proton is closest >> and hits and sticks first, 2) neutron is closest and hits and sticks first, >> and 3) the proton and neutron hit just right so that they both hit at the >> same time and stick in an interlocking fashion. When 1) happens, a neutron >> is released and you get 3He. When 2 happens, a proton is released and you >> get tritium, and when 3) happens you get 4He and a gamma. >> > > Another possible interpretation of this is that in the d(d,p)t and > d(d,n)3He branches, the two d's do not fully tunnel into a compound > nucleus. Instead, the individual nucleons (p in one case, and n in the > other) tunnel across the potential barrier along the lines of the > Oppenheimer-Phillips process and are stripped off of the d that once held > them. Preceding the scattering, there may or may not be reorientation of > the d's to account for Coulomb repulsion from the proton in the oncoming d. > > This would predict that 1) and 2) would be fairly common and 3) would be >> very rare. However, because of the Coulomb field, as the deuterium nuclei >> approach each other, it would push the protons apart, making the neutrons >> more likely to face each other, but this only happens at the last minute. >> Because of this, 2) may be slightly more favored. >> > > A different prediction would be that the strong Coulomb field in the > background orients the d's so that the constituent p's are facing out away > along the gradient towards less charge. So the incident d's would look > like this: > > Coulomb field > +++++++++++++ > > n n > | -> <- | > p p > > In this scenario, the two d's collide in parallel instead of oriented at > random or in tandem. > > Eric >
