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Comment by nielsbot | Hacker News Reader

My current favorite future fusion reactor project (I'm a layperson) is the Wendelstein 7-X: https://en.wikipedia.org/wiki/Wendelstein_7-X

Seems like they're meeting all their planned milestones and it's going well!

Excited for their next updates...

More from their project page: https://www.ipp.mpg.de/w7x

"Wendelstein 7-X is the world’s largest fusion device of the stellarator type."

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I’m also a layperson and also a fan of the 7-X, almost on purely aesthetic grounds. The plasma shape is a beautiful twisted loop, the magnets resemble a French crueler, and with the shielding and instrumentation it has all the charm of a steampunk time machine

To me it looks like alien technology. Such an organic shape. So many valves an openings. What is their purpose? How deliberate is their placement? Awe-inspiring.

Most of the ports are used for diagnostic equipment, things like laser interferometers to measure plasma density or other devices to measure plasma temperatures. Also some ports are used to inject neutral beams for heating.

It is a research reactor, so most of the openings are for instrumentation and ease of upgrades. A production design would have fewer ports.

To add to the others' responses on the purposes of ports, many of them are essentially vacuum pumps to maintain the near-perfect vacuum required for fusion to work.

Very negative take here: To me it looks like premature optimization, some politicians, mathematicians or engineers wet dream, a design that by today is probably known to be suboptimal, that probably caused millions if not billions of euros of unexpected costs, and tens of thousands of hours of migraine for the people who actually have to run and maintain the thing

Literally the primary goal is optimising the technology enough to get more energy out than energy in. Without that singular goal achieved the field has no purpose at all. It's not like theres already workable systems and they're just focusing on pushing the levels a step further just because.

This design overcomes one of the fundamental problems with the Tokamak style fusion reactors. It's like choosing quick sort over bubble sort. And yes, the difference here matters.

As a layperson, this design seems far too complex to be useful for fast iterative research and ultimately, economic replication.

It reminds me of the principle that one shouldn't start a space travel project that is estimated to take more than x years to complete, because by that time, technological progress will have surpassed its speed and capabilities, and would physically overtake it (the 'wait calculation').

Yeah, fusion is not fast to research though, ITER isn't even built yet.

They're all extremely complicated, and while this one is harder to fabricate than a tokamak, fabricating arbitrary geometries is also something we've gotten a lot better at. If this is as complicated as it has to be in order to work as required... well, that's just physics right?

The problem is unnecessary complexity, but whether that's the case here or not is still unclear.

Maybe that's the weakness of this design. But maybe it can be scaled up.

For the German speakers, this podcast is a few years old but super interesting interview with scientist working on it: https://alternativlos.org/36/

Omega Tau has a few great (and long) episodes in English:

Episode 22 is an intro to fusion power research and tokamaks.

Episode 157 is an interview of a director at ITER.

Episode 304 interviews the author of the book you’re reading.

Episode 312 is a set of interviews with experimentalists and computational theorists at W7-X.

https://omegataupodcast.net/

Keep your ear on the floor for a medium-scale HTS stellarator in the US sometime in the next ten years.

https://wistell.engr.wisc.edu

Looks like it's down for upgrades until the end of 2021.

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