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Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Thu Aug 02, 2018 12:49 pm
by ladajo
Increasing magnet power has an exponential diminishing return. It is somewhat of a red herring in regards to more magnet means better fusion with better containment. The real containment happens with adiabetic behaviour.
Just saying.

Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Thu Aug 02, 2018 1:39 pm
by paperburn1
So, in layman's terms, larger would be better

Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Thu Aug 02, 2018 2:47 pm
by dnavas
ladajo wrote:I also have to wonder about patent overlap with Polywell. Afterall, it seems to me that there is significant prior art in the concept of pinched cusps, be they line or point.
Could be an attempt to pry out what you're up to? If it isn't, I'd like to use it as such :D

Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Thu Aug 02, 2018 3:37 pm
by ladajo
paperburn1 wrote:So, in layman's terms, larger would be better
More B Field is better, to a point. And that point is probably closer than most realize.
Think in terms of squeezing something between your fingers, you reach a point quickly where more squeeze does not produce more results other than your effort.

The sheath of the plasma is really where the fun happens. And it is driven by circulating currents in the sheath creating their own B Fields.
This is a very complex system where everything is seeking its own balance. It is, IMHO, the epitome of a chaotic system.

Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Fri Aug 03, 2018 8:59 pm
by Diogenes
ladajo wrote:
paperburn1 wrote:So, in layman's terms, larger would be better
This is a very complex system where everything is seeking its own balance. It is, IMHO, the epitome of a chaotic system.

Aptly put.

Image

Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Tue Aug 07, 2018 8:24 am
by MSimon
I have done some rather simple calculations that show that for a given number of amp-turns making the device smaller increases the power inversely. i.e. half the size doubles the power.

Smaller is better.

Where this gets good is in Polywell rockets. And for rockets smaller is intrinsically better.

Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Tue Aug 07, 2018 8:35 am
by MSimon
There is a problem with cylindrical reactors.

https://arxiv.org/pdf/1808.00622.pdf
Examining plasma trapping from the context of energy equilibrium yields new perspective on MHD independent of plasma microdynamics, a suggestion as to the form of equilibrium energy distributions and guidance as to how to construct plasma traps with better performance than the cusp- and mirror-derived devices commonly in use. We also see that the MHD equilibrium holds for systems with a magnetic null such as magnetic cusps. Gauge invariance, an intrinsic feature of the electromagnetic system, leads to the observation that the θ component of the vector potential in cylindrically symmetric neutral plasmas acts against confinement. A future paper will examine the design of an optimal trap for a force-free plasma.

Re: Lockheed Martin’s Compact Fusion Reactor

Posted: Tue Aug 07, 2018 11:40 pm
by hanelyp
MSimon wrote:I have done some rather simple calculations that show that for a given number of amp-turns making the device smaller increases the power inversely. i.e. half the size doubles the power.

Smaller is better.

Where this gets good is in Polywell rockets. And for rockets smaller is intrinsically better.
Except that half the scale gives us 1/4 the cross section for coils, and corresponding amp-turns. Maybe even worse once shielding is accounted for.