Energy losses due to netural particles.

It may be difficult to separate "theory" from "application," but let''s see if this helps facilitate the discussion.
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Energy losses due to netural particles.

Post by Calmarius » Sat May 17, 2014 5:30 pm

Does anyone has data about whether how much energy a fusor (or other types of reactors) loses via light, neutrons and fast neutrals?

Someone someday might come up with a clever device that can recycle all electron's and ion's energy via electric or magnatic fields, but fields cannot affect neutral particles, so they'll be a kind of unavoidable loss.

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Chris Bradley
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Re: Energy losses due to netural particles.

Post by Chris Bradley » Sat May 17, 2014 5:59 pm

Calmarius wrote:Does anyone has data about whether how much energy a fusor (or other types of reactors) loses via light, neutrons and fast neutrals?
In general, these three parts lose almost nothing. The vast majority of energy loss is the flow of accelerated electrons crashing into the shell, which is why the shell gets hot, but you can't recapture those electrons because that process is why there is any plasma, thin as it is, at all.

Being specific, the neutrons are actually a 'gain' and take nothing from the fusor.

I would judge that the majority of accelerated deuterons are ultimately lost as fast neutrals so the question is where they are made in the potential well and where do they get turned into fast neutrals. Assuming that's random, say a half get lost and created above a half of the potential, and as the deuterons are likely created at around 1/60th of the rate of the electrons, I'd say that would amount to around 0.8%. Again, there is nothing that you could recover from these if the main origin of fusion is from these being lost to the shell, though that remains only a hypothesis (albeit a strong one, IMHO).

I'd think light lost could amount to almost 1%. Not in visible light, but if the fusor is operating in a steady mode it is basically a deuterium lamp. Not very efficient, and all the UV will be lost to the walls, but still I'd not be surprised if it was around that figure.

[My epicyclotron is, indeed, a clever device ( :) ) whose purpose was to recycle deuterons to bring them back to fusionable energies after non-fusing collisions. The magnitude of the loss of those deuterons to fast charge exchange defeated that clever device, though, and so it appears not to be clever enough!! :( A reduction of working pressure brings the process back into contention and maintaining a disc of excited plasma in which the deuterons rotate does help (i.e. locally get rid of the neutrals that can undergo charge exchange) but I have not yet seen evidence of the limitations of particle loss to charge exchange being overcome by it to the point of an improvement of fusion rate over a basic fusor.]

No energy in a conventional fusor to be recovered.

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