Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

Post by adrianN » Wed, Aug 16, 2023, 6:11 PM UTC

klodolph wrote: post #319

adrianN wrote: post #232

Earlier quoted context omitted.

It is my understanding that electrons on a curved trajectory will lose energy to electromagnetic radiation. Is that not the with electrons in a superconductor?

If you have a single free electron, and move it on a curved trajectory, you’ll see electromagnetic radiation. If you have a hypothetical continuum of charges moving in a circle, and you use Maxwell’s equations, you’ll find that given a constant charge density , no EM radiation will be emitted. If you have a superconductor, you should really be using quantum mechanics to understand it. If you can imagine that an elect…

Brilliant, thank you

Post by rkangel » Fri, Aug 18, 2023, 10:21 AM UTC

tw061023 wrote: post #77

KyleBerezin wrote: post #3

Ahh, Wendelstein is that stellerator reactor. The stellerator is really cool, and an alternative to a tokamak reactor. Tokamak is the doughnut shaped reactor, and it has a problem where the plasma near the outer circumference has less magnetic confinement. The stellerator is similar, but confines the plasma to a ribbon and folds it over on itself in a mobius-like arrangement. I used to be really interested in this, b…

What's interesting is that stellarator actually is not just an alternative, but a wholly parallel branch of evolution - it's not like one was invented strictly after another, and the authors of both designs never knew about the other's work before they completed theirs. What's even more interesting is that the fusor - the simplest possible design for a thermonuclear reactor, so simple that anyone skilled in electrica…

> The very _complexity_ of it somehow feels subtly wrong, like doubling down in the wrong direction

I read an article a while ago which sold me on the stellarator that said something like: "The tokamak has magnets in a configuration that gives simple engineering but hard physics, whereas the stellarator has hard engineering to make a complex magnet but that results in simple physics".

The engineering is a much more understood beast. It was still fairly novel as they had to have a computer do the design of the magnets, but that is now a solved problem. But then if that allows us to simplify the (very difficult and novel) physics it feels like the "obviously" correct decision.

The other thing that makes me a stellarator fan is that the JET/ITER work is later and more expensive that predicted at every stage. The W7-X provided a plan for the runs they wanted to do and upgrades to the reactor and they have basically run entirely to schedule.

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes

Re: Wendelstein 7-X: Gigajoule energy turnover generated for eight minutes