This company is running a project with extremely high pressure and low temperature https://firstlightfusion.com/technology/#our-approach

Their idea is roughly by using a railgun, accelerate a projectile and shot a target. https://youtu.be/M1RsHQCMRTw?t=492

I found another article related to this topic. In this article, the author think this solution will not work. Nuclear Fusion with extremely high pressure and low temperature. Do you guys agree with this article's opinion? Nuclear Fusion with extremely high pressure and low temperature

  • $\begingroup$ What makes you think this is low temperature? The material certainly starts at low temperature, but so does the gas used for magnetic-confinement fusion. In this case, the compression from the shockwave heats it up to very high temperature. $\endgroup$ – probably_someone Oct 22 '19 at 10:51
  • $\begingroup$ In my opinion , it is an experimental approach. They say that they have reached the plasma phase. The proof is in the pudding. It is not as simple as you are discussing, they use a shock wave approach and it is not easy to have estimates of how the energy is absorbed , not as simple as the last link you give. For example : the difference with a simple laser and many lasers focusing on one pellet. If they have a geometry where there is a focusing of the shock wave it might be possible. $\endgroup$ – anna v Oct 22 '19 at 12:29
  • $\begingroup$ @probably_someone I would say the core of the sun is but "lukewarm" for a fusion temperature, so "low" may be a relative term. $\endgroup$ – JEB Oct 22 '19 at 14:32
  • $\begingroup$ @JEB And typical inertial-confinement fusion schemes achieve temperatures many times higher than the core of the sun, so even as a relative term, it's still not low-temperature. $\endgroup$ – probably_someone Oct 22 '19 at 14:39
  • $\begingroup$ I posted a similar idea several months ago. Do you guys think my idea is possible to work? physics.stackexchange.com/q/466190 $\endgroup$ – Darwin Zou Oct 23 '19 at 1:04

I remain highly skeptical of this approach. Which is annoying, because I've talked to some of the people and they're great!

FLF's underlying fusion physics is already well known and heavily researched. It's known as inertial confinement fusion, or ICF, and it's the approach studied by the world's second-largest fusion device, NIF.

The basic idea of ICF is that if you increase the density of the fuel, two things happen - one is that the temperature goes WAY up due to the ideal gas law, and the other is that when fusion events do happen, the density is so high that the products (mostly talking about alpha particles here) don't get very far before bumping into something and causing the temperature to go up. So the hope is you get better self-heating, the fusion rate goes way up, and the fuel mass undergoes fusion really fast.

NIF attempts to reach that density basically by pushing on the outside with light. There's all sorts of practical problems in doing so, and much of the 60 years they've been working on this approach have been trying to figure these out. For instance, when you put that much light through a lens it "self focusses" down into a dot and melts a hole through it.

But throughout the time they were trying to solve these, the computers kept saying that once they did, it would work. Then they solved them, and it didn't. And the reason is that it turns out the Rayleigh-Taylor instabilities are WAY nastier than any of the simulations predicted. NIF was supposed to have 2x to 3x the performance needed to reach ignition, and to date the best result is 1/3rd.

In the end, FLF works in the same way, what's different is the way it compresses the fuel. Instead of trying to perfectly surround the fuel with light, they shoot a penny into the side of a plastic block, and the resulting shock wave accomplishes the compression.

Now they claim that they will avoid R-T and that their simulations show that. Well, so did LASNEX. And when the topic does come up, they claim they have some supr-sekret solution to R-T, but to date, no details that I can see.

If you watch the video you'll see another issue. When you cram a piece of copper into a cube of plastic at speeds that go from London to Paris in 10 seconds, you might imagine that's an impressive event. And in the video, you can see the result.


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