Energy efficient proton production?

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Quantum
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Re: Energy efficient proton production?

Post by Quantum » Sun Jun 21, 2009 3:21 pm

Carl, firstly, I don't claim to fully understand he maths involved, however your reply does not give figures for input energy versus output energy (theoretical) for this reaction.I'm curious to know what the theoretical figures are, and was hoping some-one would 'correct me', or at least start a debate on the subject.

My figures were based (loosely) on what has been published by Tom Ligon and Robert W Bussard, who, would appear to have convinced the US govt. that It will work (although I am dubious about their proposal to convert the energy directly to electricity)

I would have assumed, from the 'hype' of the British Govt in the past, that the theoretical 'payback' of a fusion reactor would be considerably higher than fifty-fold, although this will obviously depend on the reaction concerned. I assume those involving large amounts of neutrons have a higher theoretical payback, but I'm only guessing here.

There seems to be a consensus, particularly on this site, that ITER and DEMO will be destroyed by neutron bombardment from the inside out, so proton-boron 11 has to be considered, along with others, if the claims of Bussard and others are true, even if neutrons give more theoretical energy.

While I'm aware that some power stations have run at over 60% efficiency, they have all 'broken' as a result. I was being conservative with my estimates.

Finaly, it wouldn't be much of a 'forum for debate' if we all agreed all the time. I respect your right to your opinions, and I also respect your opinions in their own right.
If we are not 'collectively' working towards a solution, then all we are really doing is contributing to global warming, etc..

Quantum
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Re: Energy efficient proton production?

Post by Quantum » Sun Jun 21, 2009 3:41 pm

"the rate of fusion reactions did not produce enough energy to provide an excess of energy to keep the reaction going."


You may have mis-inderstood. I'm not suggesting that this would trigger a 'chain reaction'.....just a sort of 'energy amplifier. It needs a constant supply of protons to initiate 'reactions'....Alhough I can accept that, no mater how high the energy of the proton, inless ot is a 'head on' collision, the proton will 'glance off'.....however, if the energy level was sufficiently high, ot could still have enough energy for fusion even after 'several' glancing blows. The 'success rate' needn't be a very high percentage to reach 'break even'.

Can you explain what happens with the proton beam to target at RA? I installed this target station last year. (target station 2). The target is Tungsten, and it gives off neutrons, I'm assuming that the neutrons are 'knocked off' the nucleus, rather than being expelled due to a fusion event, but what happens to the protons?...Where do they end up?

Quantum
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Re: Energy efficient proton production?

Post by Quantum » Sun Jun 21, 2009 3:51 pm

John, Thanks...That's a very informative post.

Quantum
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Re: Energy efficient proton production?

Post by Quantum » Sun Jun 21, 2009 3:57 pm

Would this not also depend on how quickly they are accelerated away from the source?...The slower they are accelerated away, the greater the concentraion, and vice versa.

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Chris Bradley
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Re: Energy efficient proton production?

Post by Chris Bradley » Sun Jun 21, 2009 4:08 pm

Ash Small wrote:
> "the rate of fusion reactions did not produce enough energy to provide an excess of energy to keep the reaction going."
> You may have mis-inderstood. I'm not suggesting that this would trigger a 'chain reaction'.....just a sort of 'energy amplifier.
No, I understood, just a comment to reflect the total lack of efficiency of the process.


> It needs a constant supply of protons to initiate 'reactions'....Alhough I can accept that, no mater how high the energy of the proton, inless ot is a 'head on' collision, the proton will 'glance off'.....however, if the energy level was sufficiently high, ot could still have enough energy for fusion even after 'several' glancing blows. The 'success rate' needn't be a very high percentage to reach 'break even'.
I didn't say "cross-section[scattering]>>cross-section[fusion]" meant there was no future for considering alternatives, just that it's a tough nut to crack and there is currently no substantiated, viable way forward with it. I've done my best with my own discussions on breaking through this issue;

viewtopic.php?f=15&t=7183#p49055

but it is still unsubstantiated and the calcs. show you're only gonna get to a max of something like Q=3 anyway, even if there is a way to do what I suggest.

So what you're saying is right, protons will scatter and get a few 'stabs' at fusion, but the probability is a billion billionths and they get a hundred scatters before they've lost all their energy (these numbers are indicative of what can happen... you can do the calcs for yourself if you think they're not very accurate, but they're about right for, e.g. a fusor at a few 10's keV).

>
> Can you explain what happens with the proton beam to target at RA? I installed this target station last year. (target station 2). The target is Tungsten, and it gives off neutrons, I'm assuming that the neutrons are 'knocked off' the nucleus, rather than being expelled due to a fusion event, but what happens to the protons?...Where do they end up?
They'll loose their energy and take up an electron. Hydrogen embrittlement will result. Some might stay stuck in the target nucleii - all manner of things, I can imagine, but there are others far more able to say, mine are only guesses as I don't really need to know much more detail than that.

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Chris Bradley
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Re: Energy efficient proton production?

Post by Chris Bradley » Sun Jun 21, 2009 4:10 pm

I don't think so, but I don't know and would be interested to hear how to calculate likely ion concentrations in a, e.g., anode layer source.

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Carl Willis
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Re: Energy efficient proton production?

Post by Carl Willis » Sun Jun 21, 2009 4:29 pm

This is a hobby community. We don't work collectively towards a solution to anything. We work individually. Or more accurately, we play. Some play with neutrons. Some play with plasma phenomena. A few are interested explicitly in solving the energy crisis with fusion and maybe one or two of those types have built something that actually does fusion.

>your reply does not give figures for input energy versus output energy (theoretical) for this reaction

That is a bit irrelevant if getting units correct and doing a multiplication problem are a stretch! Also, there is no one solution to the question of what the "theoretical" input vs. output energy is. It is driven by circumstances particular to the method. So many rustlings about the putative virtues of p-B11 fusion have come blustering through this forum with not a single sycophant committed enough to the cause to build anything! Armchair physics. I've watched many years of this.

It's up there with shoes and ships and sealing wax and cabbages and kings. Every few months, the time has come to talk about it. Time never comes to do something other than move jaw on it though. Why reopen the debate? Don't our voluminous archives do it justice, at least in light of the vacuum of actual practical involvement with the subject?

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Quantum
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Re: Energy efficient proton production?

Post by Quantum » Sun Jun 21, 2009 4:40 pm

I can't say I disagree with you, Chris...... And I'm not even going to bother suggesting a fusor with a central cathode made of crystalline boron 11.

It looks like the MaGrid/Polywell is the only way to go.....

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Re: Energy efficient proton production?

Post by Quantum » Sun Jun 21, 2009 4:51 pm

That would probably be a function of charge (voltage), vacuum,teperature of anode and size. Do you mean +ions radiated by, or -ions attracted by the anode?

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Re: Energy efficient proton production?

Post by Quantum » Sun Jun 21, 2009 5:38 pm

Like I said, I based my calculations on those of Robert W Bussard, as published by Tom Ligon. Bussard's fusor has, I understand, $200,000,000 funding from US Govt to achieve proton-boron 11 fusion. Busard contributed to this site before he died, and Tom Ligon has discussed this topic in detail on this site and has been published elsewhere.

Bussard's fusor is an electromagnetic fusor, as opposed to an electrostatic fusor, otherwise it is identical to other fosors on this site, just a bit bigger than most (3m x 3m x 3m MaGrid).

The general consensus is that, using duterium/tritium as a fuel, the fusor would self destruct in a very short time, due to internal neutron bombardment.

I may be repeating what others have said elsewhere.

This is, after all, what the purpose of the fusor is, to produce power through fusion without self-destructing.

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