Least neutronic fusion chemistry so far?

[Lerner]

Yes, the two listed by Joe are the only ones that seem at all relevent. Both are of importance. The first one produces neutrons that are low energy, but must be shielded against. (Free neutrons of any energy are not good for organisms.) You need about a meter of shielding, which does not make a very big ball but is too large and heavy for a car. (Electric cars could re-charge at FF stations, however.) Typical design whould be an inner core of either water or plastic, followed by a layer of B-10 to absorb the slowed-down neutrons, plus a thin layer of lead to take care of the gamma ragys produced as the neutrons collide with hydorgen inthe water. The second reaction produces the exteremly short lived C11. Because of the low energy of the neutrons, activation is very very low with the materials they encounter inside the shielding. That is why we won’t have rad waste. I should add that small size helps. For example, for basic physical reasons, you can make a small vacuum chamber totally earthquake-proof, so you can’t release C11. But you can’t do that with a much larger vessel, as in building-sized reactors.

[opensource]

Thanks for the clarification!

In terms of radioactive waste, if something were to brake open even a very large FF reactor, then – as I understand it – the radioactive waste is minimal because it is pulsed and because there isn’t an accumulation of it over time. So in this paradigm, you start with fuels that are not radioactive, you end up making no long term reactants, but you do make radioactive byproducts with very short half lives (10 hours, or so). Correct?

Also, the shielding is only necessary for the first reaction (11B + α → 14N + n + 157 keV) created. And the second reaction (11B + p → 11C + n − 2.8 MeV) does not emanate beyond which sector of the reactor? That is, does the first reaction require a lot more shielding than the second?

[Joeviocoe]

Carbon-11 decays via Positron emissions, which should be just as dangerous as beta emission (high energy electrons)….
C-11 has a half-life of about 20 minutes, but should be below background radiation in 9 hours, right?

Is there any potential to extract energy from the positron emissions? The are charged particles after all (unlike neutrons, neutrinos and gamma photons) so they could maybe be used. Or are the levels so low power they wouldn’t be much use?

[Author]

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