You can get reaction data off of http://www.nndc.bnl.gov/, but as for a discussion on its use as a fusion fuel then as far as I am aware, only what I have written about it exists.Helius wrote:Where can I briefly see/read more about P+N15
It just won't work as a thermonuclear fuel due to a lowish energy output and what would, ultimately, be a crippling amount of brems.
For IEC methods, I think the general conclusion is p+11B is hard enough and p+15N just isn't on most people's map yet. I crunched the numbers because it was relevant for me to do so with regards my device.
'Sputter' isn't the correct term. An excited 20Ne momentarily exists at 5MeV above ground state. That is enough to shove off a 4MeV alpha, leaving a 12C recoiling with 1MeV, which isn't enough energy to split the 12C further.Helius wrote: I'm surprised that the reaction would sputter carbon 12; You'd think there'd be too much energy for the carbon to hold together, and instead come apart into Be and an He
The p+15N is a strong-mediated reaction. In fact, there is only this one strong-mediated outcome, which makes it truly aneutronic [rather than p+11B for which there are neutron-producing reactions, so neutron shielding is still required for p+11B].Helius wrote:does it spill its energy in a Gamma, or in the energy of the first alpha to prevent it?
What's the scoop? Has there been anyone whacking N12 with protons in a collider or IEC device somewhere?
There are weak mediated reactions, where a proton shrugs off a positron to form a neutron (e.g. p+p->D), which are very very very low in terms of probability (i.e. have a very small fusion cross-section). There are electromagnetically-mediated reactions that shove off a photon and leave the nucleon count the same in one nucleus (e.g. the D+D->4He + hv), and these are far far more common that weak ones (by 10's of oom), but are ~4 oom less likely than strong mediated reactions.
Strong-mediated reactions are where the energy goes into recoiling parts of the nucleii (without any photons emitted - because it is not mediated by the electromagnetic force!). What we want to aim for, here on earth, is only the strong mediated reactions because recoiling nucleons are heat, and as such we can do something with that to get energy from it.
The p+15N is the most common strong-mediated fusion reaction in the solar system, because it is the final step of the CNO cycle and it is the only strong mediated reaction in CNO. Each of the other 3 fusion steps are EM mediated [therefore take a longer time to actually happen, within the Sun]. This final step, which finally joins all the 4 protons together to liberate a 4He, is the quickest CNO fusion, due to it being strong-mediated (notwithstanding the 13N and 15O positron decays, which are much quicker than any of the fusions).
12C + p -> 13N [takes average 1e6 years in our Sun]
13N -> 13C + positron [takes av. 14 minutes]
13C + p -> 14N [takes av. 3e5 years]
14N + p ->15O [takes av. 3e8 years]
15O -> 15N + positron [takes av. 82 seconds]
15N + p -> 12C + 4He [takes av. 1e4 years]
(this time data as given on http://www.tim-thompson.com/fusion.html)