
Wendelstein 7-X – a fusion reactor with a twist - lobster_johnson
http://news.sciencemag.org/physics/2015/10/feature-bizarre-reactor-might-save-nuclear-fusion
======
fridek
I was lucky to see the stellator construction in progress in 2011. It is
easily the most amazing piece of tech I've witnessed with my own eyes. Not
only it's huge, but it is also built with a stunning precision (to shape the
magnetic field exactly like designed). I took couple of more raw pictures,
feel free to take a look:
[https://drive.google.com/folderview?id=0B41yKtv8jj2RdzdKbmxH...](https://drive.google.com/folderview?id=0B41yKtv8jj2RdzdKbmxHRmhJQkE&usp=sharing)

------
bhaak
If I remember my final year Gymnasium paper correctly, we've come full circle
again.

The concepts for stellarators and tokamaks were invented at about the same
time. Although one in the west and the other in the east.

At first, stellarators were all the rage in the west but then were replaced
mostly by tokamaks. Historically, tokamaks proved to be more popular because
they had simpler geometry and produced hotter plasma because of providing a
better confinement. Now, with the advantages of computer simulation, designing
a stellarator isn't as hard as it used to be. That's really exciting.

But that's how science works. Even if tokamaks might end up being a dead end
after all, there was scientific knowledge and practical experience being
gained by studying and running them which also is useful for stellarator
researchers.

OTOH ITER might be an expensive dead end, but ITER is also a political project
and as we all know, those often go awry.

~~~
dest
A challenge for stellarator researchers is the complexity of the geometry,
which makes theoretical models really tricky to build (there's already a lot
of complexity in the 'simple' tokamak ones) Howover, a significant pro for
stellarators: magnetic geometry is already twisted (necessary condition for
confinement), so it is more prone to continuous operation than tokamaks, where
you have to twist the field lines (still difficult to do continuously)

------
jakeogh
Wendelstein 7-X - from concept to reality:
[https://www.youtube.com/watch?v=lyqt6u5_sHA](https://www.youtube.com/watch?v=lyqt6u5_sHA)

Im Zeitraffer: Zusammenbau von Wendelstein 7-X:
[https://www.youtube.com/watch?v=MJpSrqitSMQ](https://www.youtube.com/watch?v=MJpSrqitSMQ)
(best @ 0.56x)

------
skimpycompiler
These big engineering projects always leave me with feelings of awe.

It so interesting to look at the shape of the coil, nothing regular. Shapes
optimized by a super computer, who knows what algorithms they've used there,
what kind of search was it, how many parameters, how long did the simulation
last.

~~~
onion2k
I'm always amazed and impressed by the people who work on these giant
projects. To do all that engineering _without really knowing if it 'll even
work in the end_ must require a huge amount of confidence in both yourself and
the rest of the team.

~~~
Faint
Confidence, or conscious willingness to take steps to unknown (will to
explore)?

------
Zardoz84
Stellarators strikes back!

I would love to know what happened with the "Perhapstron" (I write the name
correctly ?) that uses a magnetic mirror.

~~~
MrBuddyCasino
Apparently _not_ a joke, the Perhapstron exists:
[https://www.iter.org/newsline/31/850](https://www.iter.org/newsline/31/850)

------
webXL
> took 1.1 million working hours to assemble ... Wendelstein 7-X’s bizarrely
> shaped components must be put together with millimeter precision. All
> welding was computer controlled and monitored with laser scanners.

Sounds like a large 3d printer could really help make this more economical,
assuming that all of the required materials could be printed.

~~~
lorenzhs
The end of that first sentence you quote, "must withstand huge temperature
ranges and enormous forces", kind of gives away the answer -- this isn't made
from "standard" materials. 3D printing is an amazing technology that's rapidly
developing, but it's not quite that far yet.

~~~
webXL
Yeah, I was thinking more in the "fusion timescale", perhaps in 15 years you
would be able to print those kind of materials in molecular precision on a
large scale. But let's hope it continues to advance a lot faster than fusion,
so that it could help make fusion a reality.

------
upofadown
>Approval to go ahead is expected from Germany’s nuclear regulators by the end
of this month.

How could the approval of a previously unknown reactor type actually mean
anything? Is it going to be something pointless like "Reactor contains no
fissionable material. So OK!"?

~~~
lorenzhs
Stellarators are hardly a "previously unknown reactor type". They were just
infeasible for a long time because the computational power to compute the
shapes they need to be in wasn't there yet. The concept is many decades old.

------
IsTom
All I see is a blank page with ads.

~~~
Intermernet
I get the same in Chrome, but it works in Firefox.

