ALine Posted February 13 Posted February 13 Could you take alpha radiation and then strip the neutrons from it using gamma radiation and then apply radiation to heat the proton pair to lead to fusion?
exchemist Posted February 13 Posted February 13 10 minutes ago, ALine said: Could you take alpha radiation and then strip the neutrons from it using gamma radiation and then apply radiation to heat the proton pair to lead to fusion? No. A pair of protons with no neutrons would be unstable and fly apart - and you need neutrons in your fusion reaction anyway, to make helium, which is the product of the reaction. Fusion is usually between deuterium and tritium, leading to helium + a neutron that carries away most of the liberated energy. Deuterium is sourced naturally from water while tritium is "bred" by letting the escaping neutrons react with lithium in a "breeding blanket" surrounding the reaction chamber.
ALine Posted February 13 Author Posted February 13 Wouldn't the proton pair be past the coulomb barrier between the two? So would it be feasible?
Bufofrog Posted February 13 Posted February 13 28 minutes ago, ALine said: Wouldn't the proton pair be past the coulomb barrier between the two? So would it be feasible? How would gamma radiation strip neutrons from the alpha particle? Removing the neutrons from an alpha particle is not fusion anyway.
ALine Posted February 13 Author Posted February 13 Doesn't gamma radiation strip neutrons from atoms?
dimreepr Posted February 13 Posted February 13 I don't think fusion can work, in the same way that room temperature super conducting can't...
exchemist Posted February 13 Posted February 13 1 hour ago, ALine said: Wouldn't the proton pair be past the coulomb barrier between the two? So would it be feasible? No. The half life is apparently << nanosecond: https://en.wikipedia.org/wiki/Isotopes_of_helium According to my understanding there is no Coulomb “barrier” anyway, in the sense of the repulsion diminishing at very short distances. The repulsion goes on up without limit, so far as I know. Nuclear stability relies on the strong interaction outweighing it, which for 2He it apparently doesn’t.
swansont Posted February 13 Posted February 13 3 hours ago, ALine said: Could you take alpha radiation and then strip the neutrons from it using gamma radiation and then apply radiation to heat the proton pair to lead to fusion? You want to break up He-4, and then fuse it…to form He-4 You’re starting from a position where there would be no net energy released, if you somehow had perfect efficiency
ALine Posted February 13 Author Posted February 13 No I mean that if you remove the neutrons in the alpha particle the protons would be close enough to allow for the protons to fuse. That is done using gamma radiation from a natural source. It would then form deuterium and not helium-4.
Moontanman Posted February 13 Posted February 13 Just now, ALine said: No I mean that if you remove the neutrons in the alpha particle the protons would be close enough to allow for the protons to fuse. That is done using gamma radiation from a natural source. It would then form deuterium and not helium-4. The protons in an alpha particle are already fused... into an alpha particle. What do you think they would fuse into?
ALine Posted February 13 Author Posted February 13 isn't He-2 isotope decaying into H-2(deuterium) just fusion?
Moontanman Posted February 13 Posted February 13 8 minutes ago, ALine said: isn't He-2 isotope decaying into H-2(deuterium) just fusion? No, in fact there is no hydrogen 2 isotope, Hydrogen has one proton not two, hydrogen can have one or two neutrons (becoming deuterium and tritium respectively) but once it has two protons it becomes helium, two protons and one neutron is helium 3. The lack of neutrons and the effects of what happens when you remove the two neutrons is far outside my wheelhouse but I would think you need to show how to remove those two neutrons from a helium atom or alpha particle.
exchemist Posted February 13 Posted February 13 56 minutes ago, ALine said: No I mean that if you remove the neutrons in the alpha particle the protons would be close enough to allow for the protons to fuse. That is done using gamma radiation from a natural source. It would then form deuterium and not helium-4. If you consult the table in the link I provided, you will see >99.99% decay into 2 x 1H, i.e. the 2 protons just fly apart. 52 minutes ago, ALine said: isn't He-2 isotope decaying into H-2(deuterium) just fusion? But it doesn't.
ALine Posted February 13 Author Posted February 13 But it also says that there is a <0.01% decay into 2H through beta decay.
exchemist Posted February 13 Posted February 13 56 minutes ago, ALine said: But it also says that there is a <0.01% decay into 2H through beta decay. Yup, so 2/10 of F-all . You think you can run a viable fusion reactor on that basis?
Bufofrog Posted February 13 Posted February 13 1 hour ago, ALine said: isn't He-2 isotope decaying into H-2(deuterium) just fusion? If that could occur that would be a beta- decay which is not fusion.
ALine Posted February 13 Author Posted February 13 1 hour ago, exchemist said: Yup, so 2/10 of F-all . You think you can run a viable fusion reactor on that basis? bet
swansont Posted February 13 Posted February 13 3 hours ago, ALine said: No I mean that if you remove the neutrons in the alpha particle the protons would be close enough to allow for the protons to fuse. That is done using gamma radiation from a natural source. It would then form deuterium and not helium-4. It takes energy to remove the neutrons and He-4 is more tightly bound than other light atoms. deuterium has a binding energy of ~2.2MeV. That tells you the nuclear binding between nucleans. The coulomb repulsion at typical nuclear separation has an energy of at least this amount - the p-p system isn't bound (there are other considerations; there isn’t a n-n bound state, either) p-p forming deuterium (and a positron and neutrino) only releases 0.43 MeV. You might note that that’s less than the binding energy, because of that excess of Coulomb repulsion. If you want to assess the feasibility you need to run the numbers. 1
ALine Posted February 14 Author Posted February 14 What about instead of a 2 hours ago, Bufofrog said: If that could occur that would be a beta- decay which is not fusion.
Bufofrog Posted February 14 Posted February 14 That graphic does not show what you described in the OP. 1
ALine Posted February 14 Author Posted February 14 (edited) It shows that the resultant of fusion is not beta(-) decay but instead beta(+) decay. Edited February 14 by ALine
exchemist Posted February 14 Posted February 14 2 hours ago, ALine said: It shows that the resultant of fusion is not beta(-) decay but instead beta(+) decay. But that process has nothing to do with the one you were asking us to consider. What you were proposing was conversion of ²He into D. That process, which is only followed in <0.01% of cases, is indeed β+ decay, but it is not fusion. The net conversion achieved by your proposal, starting from α-particles, is ⁴He -> D. This is a convoluted fission process, not fusion and, surprise, surprise requires a net input of energy to achieve it. 1
Bufofrog Posted February 14 Posted February 14 4 hours ago, ALine said: It shows that the resultant of fusion is not beta(-) decay but instead beta(+) decay. First of all I was not talking about beta decay from fusion because that was not the scenario you brought up, however I did incorrectly say beta- decay instead of beta+ decay. Addressing your OP you said: On 2/13/2024 at 7:04 AM, ALine said: Could you take alpha radiation and then strip the neutrons from it using gamma radiation and then apply radiation to heat the proton pair to lead to fusion? Alpha radiation consists of a He nucleus, so the neutrons and protons are 'fused' together. Let's assume we can somehow remove the neutrons from the nucleus. Your question then is could the 2 protons undergo fusion. The 2 protons are already fused together, so I'm not sure what your asking. In reality if the 2 neutrons were removed from the nucleus the resulting helium isotope would be extremely unstable and one of the protons would immediately beta+ decay to a neutron forming deuterium. No fusion would occur. 1
swansont Posted February 14 Posted February 14 The binding energy of He-4 is around 28 MeV and the resulting p-p system is not bound, so removing the neutrons costs you more than 28 MeV. As I said previously, the best you could possibly do is re-form the alpha and break even.
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