Fusion power is always 20 years off. The folks at the Skunk Works are claiming that they may have a breakthrough that puts it at only ten.
Essentially, they discard the tokomak design, and… I don’t really know. Somehow, they use a differently-shaped magnetic field to contain the plasma, reducing the amount of power required to operate the thing by an order of magnitude at least. Also, it is the size of a jet engine rather than the size of a jet engine factory.
They have some pretty smart folks on board over there. Do our physicist dopers think the science is legitimate? Is this worth getting excited about, or just another ‘monumental breakthrough’ that puts abundant, clean energy barely over the horizon?
They don’t seem to have published the design (or the principle behind it) in any peer-reviewed physics journal. Normally this would be a huge red flag. I suppose in this case, it might be because someone decided it’s export-controlled material, but still, it seems strange to release this much information without publishing an academic paper.
The problem with any plasma fusion is that plasma is cranky. As found when working with Tokomaks, as you start to squeeze hotter and hotter plasma with stronger and stronger magnetic fields it behaves like squeezing a balloon, and will become unstable and bubble or “pop out” of its confinement in places.
When the plasma hits the physical wall of the vessel, that causes it to cool off. The idea with magnetic confinement is to heat the plasma and squeeze it so high-energy collisions occur regularly enough that the collisions which cause the plasma to fuse release more energy than is needed to keep the reactor running.
The theory may look good on paper, but have some practical problems like confinement failure that stop it from being practical. Will it work in the real world? There’s only one way to find out.
The design they seem to have is supposed to be a lot better for its size at containment than a tokomak. Allegedly this design has a magnetic field that becomes stronger and better at containment the further out from the plasma you go, so the plasma is a lot better contained. The thing that I find concerning is that they have magnetic coils actually inside of the plasma bottle. Running at practical power-generation levels, using Deuterium as a fuel, those are going to be exposed to a pretty bad neutron flux which won’t be good for the longevity of the superconductors.
Thinking off the top of my head, but since a patent lasts only 20 years, if you had a revolutionary concept that would earn super megabucks but only after as many as 20 years of development, might you postpone patenting (which would require you to postpone publishing, or else it becomes public domain.)
You might, if you were only ever able to get one patent. In a world where you can get many, though, what you do is you get a patent on whatever it is you’ve got right now, then you use that patented technology to do years of development to improve it, and then you patent the improvements, too. Repeat this process until it’s good enough to sell, at which point you have 20 years (or 14, I think, isn’t it?) in which you’re the only company that has that last generation of improvements, and everyone else has to either make do with the previous generation that wasn’t good enough, or has to make novel improvements of their own to catch up.
I’m curious about the two little cavities on either side. To me, it looks like they’ve probably mangled the picture and those would actually be an input and output, respectively. If they’re basing their idea on the concept of a space engine, being able to super-accelerate something certainly makes sense.
Is there some way to use a fusion reaction in that way?
I thought that tritium was a significant limiting factor in scaling up any deuterium-tritium reaction. They say that they can breed from lithium, but I remember reading an article which implied that you would need 100% efficiency in neutron conversions in a lithium blanket to maintain a steady state of fuel supply. Basically, that article stated that blanket technology was just as important as fusion technology, but much further behind.
The primary end products of the various nuclear fusion chains that might be used for power are ionized hydrogen, tritium, [SUP]3[/SUP]He, [SUP]4[/SUP]He, alpha, beta, and gamma particles, and neutrons and protons. The reaction itself produces no heavy isotopes as the processes of nuclear fission and decay do. The ionizing charged particles are all desirable because it is easy to capture their energy using magnetic or electrostatic fields that turn the kinetic energy directly into electrical potential or drive current. Tritium and helium are both valuable commodities although the production rates aren’t really high enough to yield great value by themselves.
The most hazardous products are the highly energetic neutrons (which are electrically neutral products) which are not easy to directly capture momentum from because they don’t interact electrically. They can also irradiate many materials by neutron capture and decay (the same process that occurs in nuclear fission) resulting into converting normally stable elements into unstable isotopes (‘activation’) and structurally embrittle other materials. This requires special materials in a reactor structure that are resistant to neutron effects or readily replaceable. In order to capture the energy and protect the external environment, the use of some kind of material to slow (thermalize) and absorb these energetic neutrons is required. Water is a good medium because it has a relatively high and readily controllable neutron capture cross-section and is cheap. However, unless frozen water has to be contained within some kind of vessel which would have to be resistant to neutron impingement. A better solution may be controlled irradiation and activation of nuclear materials which could then be used as fuel in more conventional fission reactors or a type of hybrid fission-fusion reaction; this could also be used for controlled burn up of radioactive waste.
Fallout is the result of material from an explosion (fission or thermonuclear fusion) being activated or contaminated with radioactive bomb residue and then being carried into the upper part of the troposphere and being distributed widely. A contained nuclear power generating plant generates zero fallout or airborne pollution of any kind, as all residue is contained within the fuel elements and the inner coolant loop is closed to the external environment. The only way to produce fallout would be a core meltdown which breaches the containment system or venting of the inner coolant loops. While this can certainly be detrimental it should be preventable with good design, and even a breech such as in Chernobyl or Fukushima released less radioactivity than a single atmospheric nuclear weapon test, hundreds of which were performed by the United States and the Soviet Union up through October 1963 when the Limited Test Band Treaty went into effect.
This proposed Lockheed design is the same that was presented at least a couple of years ago. It does not appear to be in a state of technical maturity sufficient to credibly project when it would be available for commercial energy production. The YouTube.com video is pure marketing with zero technical content, but what I know of this design does have some significant issues in achieving and maintaining stable fusion conditions. If this were really a workable system at a technology readiness level (TRL) sufficient to power aircraft or facilities Lockheed would most certainly be demonstrating it in those applications rather than making vague claims about its suitability to replace other forms of energy production.
This would also be a focus for fusion researchers around the country and in cooperative nations to bring the technology to a point that the phenomena are well characterized and ready for commercial use which would also support research and doctoral theses for hundreds or even thousands of scientists and engineers, which would result in a massive number of papers in peer-reviewed journals such as Journal of Fusion Energy, IOP Nuclear Fusion, IAEA Nuclear Fusion, and Applied Physics Letters among others, as well as being the cover story on every porn-sci rag from Scientific American to Wired.
It may be that this technology is a viable path to controlled nuclear fusion for commercial power generation at some point, but if this happens within the next decade I’ll eat my hat.