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Skunk Works Reveals Compact Fusion Reactor Details

aviationweek.com

171–180 of 375 posts

Re: Skunk Works Reveals Compact Fusion Reactor Details

#171
post #83
post #65

Earlier quoted context omitted.

No, the standard joke is "thirty years away." Or at least it was. Strangely enough the number keeps decreasing with the passage of time.

Plotting a "Year vs Years away" graph would then give us a good estimation on when we can expect to meet that expectation.

Hmm, although every successive year would contain (most) of the previous year's results, so there'll be a certain inertia.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#172
post #20

Here is more on the tech, including a drawing: http://aviationweek.com/technology/skunk-works-reveals-compa...

This looks very similar to the old Russian Gas Dynamic Trap: https://e-reports-ext.llnl.gov/pdf/366958.pdf RF and neutral beam heated steady reactor with very high mirror ratio and superconductors.

What is the operating temperature of these superconducting magnets?

I can't see how heat energy is supposed to be flowing out of that plasma envelope yet the magnets are supposed to stay at near-zero temps?

Re: Skunk Works Reveals Compact Fusion Reactor Details

#173
post #164

I'm not seeing any top physicists working in this program (McGuire is not one). I would be willing to bet 1000 EUR that their math and modeling does not add up, or they have skipped some details. Problem with fusion research like this is that the closer you get self sustainment or energy generation, the harder it gets and problems pile up. This project looks like many other similar projects that have gone bust. They…

Betting on a math error from Skunkworks? Highly unlikely. If anything, scalability will be the issue, as it always is

Re: Skunk Works Reveals Compact Fusion Reactor Details

#175
post #70

I know there are some very smart people at skunk works who've done incredible things in the past but humans have cried wolf so many times on fusion it's sort of hard to just accept until they've actually built a working reactor, shown it and had it independently verified.

Fusion physicists I know are very sceptical that this design can work. It's a variant on a known design with a known problem: the plasma leaks out of the ends of the magnetic containment. It's also unclear why Lockheed would be publicising it this way at this point, unless it's a naked ploy for more funding from the DoD, and an attempt to bring in money (and possibly pressure) from non-classified sources. That being…

> the plasma leaks out of the ends of the magnetic containment

According to this link[1] posted by another commenter, they create a "axisymmetric mirror by positioning zones of high magnetic field near each end of the vessel so that they reflect a significant fraction of plasma particles escaping along the axis of the CFR."

[1]: http://aviationweek.com/technology/skunk-works-reveals-compa...

Re: Skunk Works Reveals Compact Fusion Reactor Details

#176
post #18
post #6

Content-free article, but presumably it is this: http://en.wikipedia.org/wiki/High_beta_fusion_reactor This is not the first time they have gone public with this - Charles Chase gave a talk at Google X last year, recorded and publicly-available: https://www.youtube.com/watch?v=JAsRFVbcyUY

It sounds very similar to the way Helion Energy does it ( http://en.wikipedia.org/wiki/Helion_Energy ). Do you know what the major differences are?

Helion here. There are pretty big differences. They did get the high Beta and compact/modular parts right. The primary differences are that Helion operates entirely pulsed with simple non-superconducting magnets. That allows us to go to higher temperatures, cleaner fuels, directly recovery energy, and if everything works as planned should eliminate the wall concerns and need for particle beams.

I do think what they are doing is interesting. If its like the Gas Dynamic Trap or Tandem Mirror it has promise, atleast from the fundamental physics point of view. Researchers in Novosibirsk had encouraging results in the last 5 years. They still have a long road ahead to get to fusion-relevant temperatures, but we are staying tuned to this one.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#178

Earlier quoted context omitted.

Hyperloop case doesn't have 50 years of track record of being "just few years from now", and as far as I remember, the design was more-less feasible if only someone would get around to building it. It didn't have such hard problems to be solved as fusion still has.

This is an enlightening explanation: http://www.chforum.org/scenario2012/paper1-4-1.jpg

Thanks for the graph, and @DennisP for saying the same in written words. I recall seeing that graph once on HN, but for some reason I didn't pay attention to it back then.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#179
post #57

> 100-megawatt reactor measuring seven feet by 10 feet, which could fit on the back of a large truck A typical thermal power station has an efficiency below 50% for electricity generation, so the plant dissipates at least as much heat as it generates electrical power. I wonder how you could get rid of 100MW of waste heat from a volume small enough to fit on a truck. That's a heat flux of more than a megawatt per squa…

I don't think they're actually proposing to put it on a truck. I think this is a "football fields" type size comparison.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#180
post #125

25 years ago my nuke professor used to scoff at some of the claims of the fusion researchers. The problem is the high energy neutrons flying out of the reactor will neutron-activate every material within the vicinity. He thought the radioactivity and nuclear waste of a fusion reactor could be worse than a fission reactor. Also he thought that fusion researchers were vastly underestimating the problem of neutron embri…

With D-T fusion you would have more activation of the reactor materials, because D-T produces such high-energy neutrons. What you wouldn't have is transuranics, which make up the bulk of our nuclear waste (and all of the really long-lived stuff), or fission products (the most radioactive stuff, like the cesium and strontium we heard about after Fukushima). But D-T is only the easiest form of fusion. Next up is D-D, w…

Correct me if I am wrong, but each of these "steps" is a research project in their own right.

The AviationWeekly article mentioned D-T fusion for the Lockheed prototype and includes a diagram with the caption "blanket absorbs neutrons to breed fuel and transfer heat to turbines". This "blanket" will be tons of material that would be activated during operation and would have to be disposed of at EOL. Also, modern materials include many trace elements within the main molecular lattice such as cobalt, chromium, etc in steel and in some ways might be more difficult to process than used fuel rods.

I worked in the nuclear power industry decades ago and I don't recall the how the energy of fusion neutrons vs fission neutrons compared but I thought that in general fusion neutrons were significantly higher. Most power fission reactors also have neutron moderators which help to reduce the activation and embrittlement problems. Nevertheless, core components in fission reactors are already experiencing neutron embrittlement and has been a concern.

I'm not trying to be negative on fusion power but these overly optimistic reports have to be read with a critical eye.

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