You heard about "The Sheared Flow Stabilized Z-Pinch"

[Lord of plasma]

TL;DR Summary

The very neat and simple form of nuclear fusion power, that has shown to be difficult to work a team of Washington University has made great progress with.

I couldn't find any threads about this experiment on this forum, so here I try to introduce it and also I later have som suggestion to improve it.

Very shortly the machine produce a ring formed sheet along a rod, which climbs up and at the end of the rod it stretch out and compress to a thin thread. A so called Z-pinch. Here is where the interesting things happened. The thread compresses and heat even more and fusion start. Unlike many other Z pinch devices this gives a stable thread for som time. Some time is tens of microseconds. Yep that is long when it comes to fusion of the more high density kind.

The article Sheared flow Z-pinch shows that the speed is different at different radies and that is what stops the thread to kink or sausage for some time. It's a pulsating kind of device.

They have been working on this over 10 years and recently they have achieved fusion and of course then high temperatures and high density in the plasma. It's seems very promising and I so much like the simplicity of the device. Then you need MA current, several kV and other quite challenging features, but still not impossible.

What do you know about it or want to comment on it?

 

[mfb]

I don't trust extrapolations over 7 orders of magnitude. But assuming this works and nothing unexpected shows up: How much energy do they hope to get per shot, and how many shots per second of an inherently destructive process could a reactor do?

The Z machine had megaamperes 20 years ago and runs at tens of MA now. What is so different that limits their current to 50-200 kA?

 

[Lord of plasma]

I havn't yet found fact about how much energy they need in every shot and what frequency they need. Espacially the last thing I don't think they even bother because they just want to prove the concept. Scaling up Sheared flow Z-pinch tells about how much current they need wit D-T fuel and now they using deuterium and that is a big difference. 1,5 MA is what a commercial power plant need according to them.

I think the most important reason why they need less current, is that they have much longer pulses. If I remember correct the pulse in the Sandiego Z-machine is just some tens of nanoseconds. So differens are several hundred times if not more. n*T*tau describes something what it take to make fusion. Quiet simply more of one of them makes it less necessary to have so much of the other two. Of course there are some absolute limits of temperature.

 

[Lord of plasma]

I wonder if you can do the same thing (as sheared flow stabilezed-Z pinch by W.U) with different potential, namely different speed along the radii, se attached pic. That would be even simplier and maybe the pinch can be constant more or less.

 

[Lord of plasma]

Sorry for last confusing replay. I had to make a change a thing and couldn't take it back.

As I begun last time I wonder if you can do the same thing (as sheared flow stabilezed-Z pinch by W.U) with different potential, namely different speed along the radii, se attached pic. The idea is that ions that travel from potential +2U has higher speed then ions from potential +U. And thereby you can achieve a stable pinch more or less constant. The electric field is the same for the ions, but not the speed at the end.