Didn't know that. Now I'm really curious to see if this will work.rnebel wrote:Nothing is a slam dunk. If the transport doesn't work out, then none of the systems will work. Right now, the transport looks fine. The question is whether or not it will scale.
We Will Know In Two Years
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Sort of. We can assume that if there's energy produced by fusion, we can get it. The question is, how much energy do we have to inject to make up for losses (transport=leakage of high-energy electrons and fuel ions through the confinement, leading to loss of their energy)? If it's significantly less than the fusion power, we're good (at least for simple fuels where stuff like bremsstrahlung isn't an issue).
Last edited by 93143 on Tue May 19, 2009 6:49 pm, edited 1 time in total.
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Bremsstrahlung would be an issue when the plasma density goes up when trying to scale, no matter the how simple the fuels, this is one of the hurdles in Tokamak fusion reactors.93143 wrote:Sort of. We can assume that if there's energy produced by fusion, we can get it. The question is, how much energy do we have to inject to make up for losses (transport=leakage of high-energy electrons and fuel ions through the confinement, leading to loss of their energy)? If it's significantly less than the fusion power, we're good (at least for simple fuels where stuff like bremsstrahlung isn't an issue).
Dr. Nebels says the transport , at the moment, seems to be working, it will be interesting to see if it scales.
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I would say "easy" rather than "simple", meaning a relatively large fusion cross section.gblaze42 wrote:Bremsstrahlung would be an issue when the plasma density goes up when trying to scale, no matter the how simple the fuels, this is one of the hurdles in Tokamak fusion reactors.93143 wrote:Sort of. We can assume that if there's energy produced by fusion, we can get it. The question is, how much energy do we have to inject to make up for losses (transport=leakage of high-energy electrons and fuel ions through the confinement, leading to loss of their energy)? If it's significantly less than the fusion power, we're good (at least for simple fuels where stuff like bremsstrahlung isn't an issue).
The bremsstrahlung issue is independent of density, which is one reason the objections to p-B11 are so robust. Both the fusion power and the bremsstrahlung power scale with n^2.
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That's a mighty terse statement. It may be that you have given your reasoning before, but I have forgotten it.rnebel wrote:I think we have a real shot at p-11B. I think it is possible to beat the Bremstrahlung issue.
- What do you anticipate for the ratio of P_brems to P_fusion?
- Do you expect to get there by running with a low value of <E_e>/<E_i> or by tailoring the electron energy distribution?
The present projected Q values for p-11B vary from about 1.7 to about 12, depending on how the physics breaks. The details of how you do that are surprisingly subtle and coupled, and I'm not going to go into that in this forum. I view this as an "optimistic problem". There are a lot more serious issues that need to be dealt with than this one.
It is? I would think the probability for electrons to have a change in momentum goes up as the density of plasma goes up, as the likelihood that an electron would encounter a proton/nucleus increases. I'm curious, not being a plasma physicist.Art Carlson wrote: The bremsstrahlung issue is independent of density, which is one reason the objections to p-B11 are so robust. Both the fusion power and the bremsstrahlung power scale with n^2.
That's what I meant. "Simple" as in "not difficult". "Easy" would have been better.Art Carlson wrote:I would say "easy" rather than "simple", meaning a relatively large fusion cross section.
It does. So does the probability of fusion events. Net result is a wash.gblaze42 wrote:I would think the probability for electrons to have a change in momentum goes up as the density of plasma goes up
Except that (as I understand it... minimally) the fusion rate is related to the a density function of BOTH species, p and B11, but the Brem is related most significantly to the density of B11. You can, in theory, increase fusion and decrease Brem by increasing the ratio of p to B11 and playing with the total pressure.93143 wrote:It does. So does the probability of fusion events. Net result is a wash.gblaze42 wrote:I would think the probability for electrons to have a change in momentum goes up as the density of plasma goes up