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

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

#131

Post by colordrops »

KyleBerezin wrote: post #114
themagician wrote: post #63

Earlier quoted context omitted.

I find the geometry of things like this fascinating. We typically think in such simple shapes. I feel like my brain can do triangle, rectangle and maybe hexagons and that's about it. I remember when I finally understood radians enough to really understand circles and waveforms—I felt so enlightened. Like I actually remember the moment when it clicked. For years I was just "doing the work" without actually understandi…

Yea they are kinda confusing, especially when you get into the 3D ones like klien bottles and roman surfaces. I also recently learned that if you make a mobius shaped transmission line (like a ladder line) and you send a pulse down it, that pulse will continue looping until it dissipates (or forever if it is a superconductor). https://www.microwavejournal.com/articles/21001-printed-reso... I have no idea if there are…

Are real life superconductors ideal, i.e. they truly would store a charge forever (at least until the material disintegrated)? Or is there some sort of loss, albeit much less than typical resistance?

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

#133

Post by cyberax »

t0mas88 wrote: post #28
aeyes wrote: post #11

Earlier quoted context omitted.

In the German Alternativlos podcast the Wendelstein team (Prof. Dr. Thomas Klinger, Dr. Adrian von Stechow) recently stated that it is already feasible, they estimate a cost of ~€20B and a 5 year construction time for a commercial fusion power plant if we started now. https://alternativlos.org/51/

For less than 15 billion euro you could buy enough solar to power a country the size of the Netherlands. With 5 billion to spend on batteries you might even make it through night time usage. Or in other words: Fusion is too expensive at this point to be useful.

You'll freeze to death in winter, but that's a minor thing. Living is overrated.

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

#134

Post by gus_massa »

MichaelZuo wrote: post #123
NateEag wrote: post #121

Earlier quoted context omitted.

Helion is planning to use induction to generate electricity from the fusion reaction's generated magnetic field, IIUC: https://www.helionenergy.com/faq/ (See "How does Helion generate electricity from fusion?" question)

Which doesn't make sense for power generation since there will always be some percentage of neutrons produced by any type of fusion reaction that can only be useful for generating steam. To entirely skip the steam cycle portion is to intentionally make a much less efficient design. For space-constrained, high-value, applications where economics don't matter that much, such as a submarine, that would make sense, but o…

They plan to use 2D + 3He -> 4He + 1H, so no neutrons https://en.wikipedia.org/wiki/Aneutronic_fusion#Candidate_re...

(I'm still not convinced of their explanations, but a fast proton may be easy to catch by the magnetic field and create the effect they want.)

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

#135

Post by [deleted] »

starkrights wrote: post #84
Retric wrote: post #69

Earlier quoted context omitted.

You messed up at your last step 1 millionth = 1mm, 10 millionth = 0.1mm, 100 millionth = 0.01mm 0.01mm is very difficult when you’re talking large custom objects with complex shapes.

I think the original commenter is right- correct me if I missed what you’re getting at. Keeping it all in the same units until the end here: 1 millionth of 1 meter = (1 / 1,000,000)m = (1e-6m) 1 millionth * 100 = 100 millionths => (1e-6m) * 100 = (1e-4m) = 100 millionths (1e-4m) = .0001m | 1m = 1000mm => .0001m*1000 = .1mm

[deleted]

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

#136

Post by tw061023 »

waterheater wrote: post #97
tw061023 wrote: post #77

Earlier quoted context omitted.

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…

Compared to a tokamak, the stellarator bring engineering efficiency while matching performance. Though ideas for the tokamak and the stellarator may have emerged together, the main reason tokamaks were built first is because they COULD be built. Without computer-assisted magnet design, stellarators simply couldn't be properly built; the magnetic geometries are just too complex. In the long run, it's not known stellar…

I understand the theory. I just hope I will live long enough to see a winner in this race.

To be honest, I've been interested in the domain for quite a time and I still want to build a fusor or a polywell at some point just to see it glow. Probably won't happen though.

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

#137

Post by jcheng »

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.

This made me think of modern jet fighters being designed to be aerodynamically unstable, making them all but impossible for human pilots to operate without flight computers. Apparently the maneuverability benefits make the added complexity more than worth it.

https://en.wikipedia.org/wiki/General_Dynamics_F-16_Fighting...

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

#138

Post by Retric »

starkrights wrote: post #84
Retric wrote: post #69

Earlier quoted context omitted.

You messed up at your last step 1 millionth = 1mm, 10 millionth = 0.1mm, 100 millionth = 0.01mm 0.01mm is very difficult when you’re talking large custom objects with complex shapes.

I think the original commenter is right- correct me if I missed what you’re getting at. Keeping it all in the same units until the end here: 1 millionth of 1 meter = (1 / 1,000,000)m = (1e-6m) 1 millionth * 100 = 100 millionths => (1e-6m) * 100 = (1e-4m) = 100 millionths (1e-4m) = .0001m | 1m = 1000mm => .0001m*1000 = .1mm

Ops, 100 ( 1 millionths of a meter) is a much more reasonable tolerance here than 1 / (100 millionth) of a meter.

I am to used to people saying 100 millionth of a meter to mean 10 nm or 0.01 µm which would have looked insane if I had written that.

Aka 100 millionth vs 100 millionths

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

#139

Post by TaylorAlexander »

cmplxconjugate wrote: post #39
TaylorAlexander wrote: post #19

Speaking of fusion does anyone know what is going on with SPARC at Commonwealth Fusion Systems? I have been very excited about their system but they are understandably in a deep development and construction cycle after a $2B investment, so all their news page has for the last year are updated business deals and awards. I would love to hear how reactor construction is going.

My best friend works for them in diagnostic sub-systems development. The product is still a long way off delivery with many systems being actively designed and refined. Basically it’s busy but will still be quite a while (3-5+ years at least).

Makes sense. I would love to see a blog post with some progress pics, but I understand that building a fusion reactor is simply a slow process!

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

#140

Post by golem14 »

waterheater wrote: post #108
KyleBerezin wrote: post #101

Earlier quoted context omitted.

One guy asked why the mobius aspect is needed and I couldn't answer. I know a lot of stellarators aren't odd-period like Wendelstein, and the old designs didn't do folding at all. Do you know what improvements the mobius design has over something like TJ-II?

The helical path creates a twist in the plasma which cancels out the drift forces. This is what I meant by "tricking" the plasma. User mjfl gives an even more technical explanation: > By twisting the plasma into a shape where the curl of B (proportional to J) is parallel to B, i.e. a helix, the cross product is 0, and thus there are no net magnetohydrodynamic forces on the plasma. Hope all that's a good answer for yo…

I suppose that any number of twists would be OK, but the more twists, the less efficient ?

Is that what you are saying ? Or are there other constraints on the number of twists (e.g. must be odd, ...)

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