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Comment by nerdy | Hacker News Reader

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.

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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 said, if they've genuinely cracked it, the game changes so much as to be unrecognisable.

From the Aviation Week article that flexie linked: "The team acknowledges that the project is in its earliest stages, and many key challenges remain before a viable prototype can be built."

They don't actually say it, but it sounds like they've only got computer models to work with at this point. Not very likely that they've actually cracked it.

Aditional weird: this is the second round of publicity they've had on this project, for what looks like no progress. Why publicise? Why now?

Push the oil and natural gas markets lower, pile on all the other factors pushing them down right now, and further harm Russia's economy.

I'm half joking, but I'd keep an eye out for more unusual energy related press releases, to see if that'll confirm that it's a media blitz aimed at the oil market etc.

I asked a friend at LM and they say it's probably because someone wanted to file a patent.

For what it's worth, in the Google [X] talk last year, they briefly mentioned running actual plasma confinement experiments (although I guess not reaching fusion conditions or that would probably have been publicized).

https://www.youtube.com/watch?v=JAsRFVbcyUY

> 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...

When you're dealing with a plasma at 20 million kelvin, the leftovers from that "significant fraction" that don't get reflected can really ruin your day...

LLNL scientists almost tested a similar device (see 'MFTF') but the project was cancelled in 1986 before it was turned on.

It is possible though that though earlier attempts failed because the computational resources and the plasma dynamics modeling available at the time were not sufficient to design such a reactor.

I would guess that we have a much better understanding of plasma physics and faaaaar greater ability to model it now - that could lead to designs that can mitigate previously discovered issues with the concept.

Reminded me of a quote,

"It really is a vanishingly small amount of plasma that escapes from the device."

"What part of 'It is just like the Sun' did you not understand?"

Historically, the problem with the cylinder + mirror configuration is that there are discontinuities (corners) at the seams where the mirrors join on at the end. So you lose a lot of plasma there. Interested to see how they've overcome that.

Your link is actually the original article that this post links to. (It does indeed contain the quoted sentence.)

Maybe it's the reverse. It is a PR to make an impression that the fusion is just around the corner to discourage other nations from investments into tokamaks and improved fission reactors, out of impression that this fusion breakthrough will make them all soon obsolete.

This is a very good point. Extraordinary claims...

If you haven't hung around talk-polywell.org before, you might want to. It's focused on the polywell but they seem to at least try to fairly evaluate all contenders.

New confinement techniques (NIF, this article, Helion, Polywell) are actually making real progress. So it's becoming less likely that an announcement like this is 100% vapor.

Put another way, we're getting to the point now where we have tools sufficient to actually know what the results will be. That, more than anything, is the benefit from the billions spent on tokamaks.

The AviationWeek article even mentions that the LMSW team drew from Polywell:

> "We also have a recirculation that is very similar to a Polywell concept," he adds, referring to another promising avenue of fusion power research. A Polywell fusion reactor uses electromagnets to generate a magnetic field that traps electrons, creating a negative voltage, which then attract positive ions. The resulting acceleration of the ions toward the negative center results in a collision and fusion.

It's great that they've scoured even the non-mainstream ideas and incorporated them.

It doesn't talk about how recirculation is used. I was thinking maybe it has something to do with sealing the cylinder end caps, to keeping plasma loss to near zero?

I followed the ecat (http://ecatnews.com/) story for a year or so until my BS alarm started getting really loud - but just the prospect of it was so exhilarating, it was hard to resist the enthusiasm overflow...

Now this sounds way more serious than Andrea Rossi's saga. But I did get a lot tougher on my wait and see stand.

I'm still waiting on a Steorn Orbo replication...

Yes!

couple either of those to a reactionless drive and head off to alpha centauri for vacation...

We have working reactors they just don't output more energy than they consume.

We should be throwing more money at this...

There have even been reactors that produce more energy than they consume, just not in a practical, economical way.

Not really, but it's close. The Japanese ran an experiment that would have broken even if Japan were allowed to have tritium.

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