Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

New records on Wendelstein 7-X

iter.org

Post reply on HN
Print view View original

91–100 of 112 posts

Re: New records on Wendelstein 7-X

#91

Post by JumpCrisscross »

davrosthedalek wrote: post #84
JumpCrisscross wrote: post #68

Earlier quoted context omitted.

> real problem with fusion power is that even if they figure it out, it still won't be cost competitive with solar and wind This is difficult to say when comparing an emerging technology with an established technology in an emerging economy. Based on every historical prior, it would be surprising if there weren't diminishing returns to solar and wind. And I wouldn't underestimate the degree to which power is, in part…

Additionally, the total amount of solar and wind is limited. Surely more than we need now, don't get me wrong, but how much more? Factor 2? 10? I could see a future that is extremely energy hungry, and not just because of AI.

> the total amount of solar and wind is limited

I'd be shocked if we max out on insolation before area we're willing to cover with solar panels and windmills.

Re: New records on Wendelstein 7-X

#92

Post by WhereIsTheTruth »

greesil wrote: post #90
chris_va wrote: post #48

A better link: https://www.ipp.mpg.de/5532945/w7x?c=5481737 (there is some irony in using the iter.org link for a stellarator announcement) 1.8GJ over 360 seconds, beta of 0.03

The irony is delicious. Especially considering the total budget of it is $340 millions vs ITER's tens of billions.

Their findings complement and help each other, there is no irony in there

Re: New records on Wendelstein 7-X

#93

Post by Ey7NFZ3P0nzAe »

greesil wrote: post #90
chris_va wrote: post #48

A better link: https://www.ipp.mpg.de/5532945/w7x?c=5481737 (there is some irony in using the iter.org link for a stellarator announcement) 1.8GJ over 360 seconds, beta of 0.03

The irony is delicious. Especially considering the total budget of it is $340 millions vs ITER's tens of billions.

To be fair, they might not be totally independent figures in the sense of, I would be surprised if the cheaper project did not benefit at all from the knowledge created by the larger project.

Re: New records on Wendelstein 7-X

#94

Post by lux44 »

GMoromisato wrote: post #87
StevenWaterman wrote: post #7

Earlier quoted context omitted.

Your question reminds me of the image showing how SpaceX raptor motors evolved https://imgur.com/a/4w3q3lS

To be fair, the reason the right-most Raptor looks so clean is because they moved all the piping (all the complexity) to inside the casing. And the reason they made the effort is because the casing protects the tubing from the heat of re-entry. Otherwise they'd have to waste mass on heat shielding. [Take a look at videos of Superheavy Booster returning back to the launch tower--the bottom engine sections starts to gl…

> the bottom engine sections starts to glow from the heat

It's fuel burning, not glow. Speed is too low for glowing; glow would start at the edge, not from deep inside the skirt etc.

Re: New records on Wendelstein 7-X

#95

Post by cenamus »

johannes1234321 wrote: post #79
i_am_proteus wrote: post #58

Earlier quoted context omitted.

>The fact that W7-X results are on a par with JET is remarkable because JET had three times the plasma volume of Wendelstein 7-X. What's important here is that W 7-X is a stellarator , a different type of fusion reactor from almost all prior reactors (they are tokamaks), with a smaller volume than the co-record holder. That a stellarator gets these results with a much smaller fusion volume is promising for the perfor…

> from almost all prior reactors (they are tokamaks) Tokamak and Stllerator are about equally old, 1953 vs 1954, while both types where for a period developed in secrecy behind either side of the iron curtain till end of the 1960ies where collaboration started. IPP was founded in 1960 (by, among others, my dad) and focussed on Stllerator since then (while collaborating in JET and ITER around their tokamak projects)

Apparently stellarators only became feasible recently, mostly due to vastly improved computing power, which they need to optimize the crazy shapes (https://www.ipp.mpg.de/w7x gives an idea)

(Heard that on a podcast with two of the lead physicists/engineers working there)

Re: New records on Wendelstein 7-X

#96

Post by ygra »

Ey7NFZ3P0nzAe wrote: post #93
greesil wrote: post #90

Earlier quoted context omitted.

The irony is delicious. Especially considering the total budget of it is $340 millions vs ITER's tens of billions.

To be fair, they might not be totally independent figures in the sense of, I would be surprised if the cheaper project did not benefit at all from the knowledge created by the larger project.

Help on either project actually flows both ways. If I remember correctly, Wendelstein 7-X provided experience and know-how regarding microwave heating and welding large plasma vessels. In the end they're scientists and engineers and don't seem to see the other project so much as competition than a way to learn more than just with one of them.

Re: New records on Wendelstein 7-X

#97

Post by XorNot »

greesil wrote: post #90
chris_va wrote: post #48

A better link: https://www.ipp.mpg.de/5532945/w7x?c=5481737 (there is some irony in using the iter.org link for a stellarator announcement) 1.8GJ over 360 seconds, beta of 0.03

The irony is delicious. Especially considering the total budget of it is $340 millions vs ITER's tens of billions.

Wendelstein is a plasma research machine, not a net energy machine. There's no version at that price point which is a viable power plant - ITER is the smallest viable power plant (but you wouldn't want to run it). DEMO is it's successor which is 10x larger in terms of vacuum volume and is meant to be an actual electricity producing plant.

Re: New records on Wendelstein 7-X

#98

Post by johannes1234321 »

cenamus wrote: post #95
johannes1234321 wrote: post #79

Earlier quoted context omitted.

> from almost all prior reactors (they are tokamaks) Tokamak and Stllerator are about equally old, 1953 vs 1954, while both types where for a period developed in secrecy behind either side of the iron curtain till end of the 1960ies where collaboration started. IPP was founded in 1960 (by, among others, my dad) and focussed on Stllerator since then (while collaborating in JET and ITER around their tokamak projects)

Apparently stellarators only became feasible recently, mostly due to vastly improved computing power, which they need to optimize the crazy shapes ( https://www.ipp.mpg.de/w7x gives an idea) (Heard that on a podcast with two of the lead physicists/engineers working there)

Yes, they are complex and require both, complex calculation and precise manufacturing and 7x is the first one being energy-positive, but tokamaks aren't really ahead either.

Re: New records on Wendelstein 7-X

#99

Post by noobermin »

i_am_proteus wrote: post #58
tgtweak wrote: post #43

Earlier quoted context omitted.

Here is an actual article with some context - and a reality check that other experimental reactors in the past have sustained similar triple product for longer durations... https://www.ipp.mpg.de/5532945/w7x

>The fact that W7-X results are on a par with JET is remarkable because JET had three times the plasma volume of Wendelstein 7-X. What's important here is that W 7-X is a stellarator , a different type of fusion reactor from almost all prior reactors (they are tokamaks), with a smaller volume than the co-record holder. That a stellarator gets these results with a much smaller fusion volume is promising for the perfor…

NIF did it with an EVEN smaller plasma volume.

Sorry this is nice for the Wendelstein itself but they are overselling it, albeit in a way that isn't too out of the norm with academic press releases.

Re: New records on Wendelstein 7-X

#100

Post by TheOtherHobbes »

pama wrote: post #22
bradleyy wrote: post #12

In any future fusion power plant, a plasma with a high triple product must be maintained for long periods. I love vague terms like "long periods". Long compared to the Planck length? Geological time? Is the advertised 43 seconds almost there or "off by 17 orders of magnitude?"

I agree vague language in popular press is sometimes annoying. “Off by 17 orders of magnitude” would be off by 136 billion years, so not that much for sure. Assuming you want to be able to test the plant and or maintain it once per year, 43 seconds is less than 6 orders of magnitude off. The jump was more than a full order of magnitude compared to past records, so another handful such developments and we are there.

Any fusion reactor that produces masses of free neutrons is uneconomic, because the neutrons are ridiculously corrosive to everything they collide with. Neutron activation produces a mess of radioactive isotopes, some of which fission quickly. It doesn't take long - certainly much less than a year - before you're left with components that no longer do their jobs and are also radioactive.

This is a much less sexy problem than containment, but it's a showstopper for commercialisation. You can just about imagine an epically huge reactor with unfeasibly powerful containment fields that trap fusion in the centre of a large cloud of hydrogen, which captures neutrons to make tritium to power the reaction. But that's completely unbuildable with current tech.

Aneutronic fusion is possible, but it happens at even more extreme temperatures, which are barely theoretical at the moment.

At this point we've been chasing fusion for more than 70 years, and commercialisation is as far away as ever.

You might as well just build yourself a small star.

Or perhaps even spend all that research money on making better use of the star we already have.

Post reply on HN