Wendelstein 7-X

Point out news stories, on the net or in mainstream media, related to polywell fusion.

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prestonbarrows
Posts: 78
Joined: Sat Aug 03, 2013 4:41 pm

Re: Wendelstein 7-X

Post by prestonbarrows »

AcesHigh wrote:this article claims Wenderlstein 7X was the first in the world ever to produce hydrogen plasma? Other fusion prototypes only produced helium plasma. Is there any veracity to that?
No. That is just a really horrible article. Here is a much better one directly from the source. http://www.ipp.mpg.de/4010154/02_16

W7X is the world's largest stellerator. Today was the first time the system has run hydrogen. Every other major fusion reactor for nearly 100 years now has used hydrogen; there is nothing inherently special or difficult about a hydrogen plasma.

Helium is generally easier to breakdown with microwave heating. This is important on a fresh system which will be full of impurities that interfere with the plasma and degrade performance. Helium is a non-reactive noble gas that does a good job of scrubbing out impurities from the walls while also being easy to pull out of the system later when you no longer want it around. Performance improves with each shot as the system is cleaned. This stage is about testing out all the diagnostics, power, vacuum, cryogenic, and other systems which need to work as a synchronized group for a successful shot.

Starting to use hydrogen is a noteworthy step since it indicates that the initial housekeeping phase is complete and the real science is starting; it makes for a nice milestone and photo-op.

D Tibbets
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Joined: Thu Jun 26, 2008 6:52 am

Re: Wendelstein 7-X

Post by D Tibbets »

Skipjack wrote:
AcesHigh wrote:this article claims Wenderlstein 7X was the first in the world ever to produce hydrogen plasma? Other fusion prototypes only produced helium plasma. Is there any veracity to that?
Thats nonsense...
I have no idea as to the veracity of the statement, but it is mostly meaningless. Helium is traditionally the gas of choice for studying plasmas. It is safer, lends itself to leak detection, etc. Any results other than actual fusion events (measuring neutrons) is easily handled by helium and these results can be extrapolated to other gas choices.Final measurements confirming things like Bremsstruhlung characteristics in a given machine, etc may be needed as a final step, but for the basics, helium is convenient.

Having said that, and considering the computational difficulty of modeling this system, hydrogen may be more precise. The difficulty in this excuse though is that a mixture of deuterium and tritium may behave more like helium (helium4) than protium/ hydrogen. The Z and inertia of the particles may need very fine understanding. Keep in mind that if this is an ignition machine fusion produced helium4 behavior may also be a consideration.

Dan Tibbets
To error is human... and I'm very human.

Skipjack
Posts: 6805
Joined: Sun Sep 28, 2008 2:29 pm

Re: Wendelstein 7-X

Post by Skipjack »

D Tibbets wrote:
Skipjack wrote:
AcesHigh wrote:this article claims Wenderlstein 7X was the first in the world ever to produce hydrogen plasma? Other fusion prototypes only produced helium plasma. Is there any veracity to that?
Thats nonsense...
I have no idea as to the veracity of the statement, but it is mostly meaningless. Helium is traditionally the gas of choice for studying plasmas. It is safer, lends itself to leak detection, etc. Any results other than actual fusion events (measuring neutrons) is easily handled by helium and these results can be extrapolated to other gas choices.Final measurements confirming things like Bremsstruhlung characteristics in a given machine, etc may be needed as a final step, but for the basics, helium is convenient.

Having said that, and considering the computational difficulty of modeling this system, hydrogen may be more precise. The difficulty in this excuse though is that a mixture of deuterium and tritium may behave more like helium (helium4) than protium/ hydrogen. The Z and inertia of the particles may need very fine understanding. Keep in mind that if this is an ignition machine fusion produced helium4 behavior may also be a consideration.

Dan Tibbets
JET (among others) certainly had experiments using hydrogen (deuterium and tritium) plasma. So I dont get why they claim to be the only ones.

crowberry
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Joined: Sun Sep 08, 2013 6:34 am

Re: Wendelstein 7-X

Post by crowberry »

The press release after the first hydrogen plasma event in Wendelstein 7-X can be read here http://www.mpg.de/9926419/wendelstein7x-start.
The present initial experimentation phase will last until mid-March. The plasma vessel will then be opened in order to install carbon tiles for protecting the vessel walls and a so-called “divertor” for removing impurities. “These facilities will enable us to attain higher heating powers, higher temperatures, and longer discharges lasting up to ten seconds”, explains Thomas Klinger. Successive extensions are planned until, in about four years, discharges lasting 30 minutes can be produced and it can be checked at the full heating power of 20 megawatts whether Wendelstein 7-X will achieve its optimisation targets.

Maui
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Joined: Wed Apr 09, 2008 12:10 am
Location: Madison, WI

Re: Wendelstein 7-X

Post by Maui »

Ars Technica has pretty big article up on the 7-X: Wibbly-wobbly magnetic fusion stuff: The return of the stellarator

Carl White
Posts: 476
Joined: Mon Aug 24, 2009 10:44 pm

Re: Wendelstein 7-X

Post by Carl White »

https://www.techtimes.com/articles/2313 ... he-sun.htm
The stellarator has reached a temperature of 40 million Kelvin at a plasma density of 0.8 x 1020 particles per cubic meter. This was maintained for a total of 26 seconds. Operators were also able to feed it as much as 18 times more energy, reaching up to 75 megajoules of energy that was fed into the plasma.
The record-breaking fusion product was made possible by upgrading the interior components of the Wendelstein 7-X. A new lining of graphite tiles for the chamber allowed the plasma to reach higher temperatures. The lining, called a divertor, keeps the plasma in its twisting sphere while protecting it from stray particles that may make it unstable.
EDIT: here's a link to the press release from which the article is derived:

http://www.ipp.mpg.de/4413312/04_18

Carl White
Posts: 476
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Re: Wendelstein 7-X

Post by Carl White »

"The Wendelstein 7-X Nuclear Fusion Device Concept Proves Its Efficiency"

https://scitechdaily.com/the-wendelstei ... fficiency/
One of the most important optimization goals underlying the Wendelstein 7-X fusion device at Max Planck Institute for Plasma Physics (IPP) in Greifswald has now been confirmed. An analysis by IPP scientists in the journal Nature shows: In the optimized magnetic field cage, the energy losses of the plasma are reduced in the desired way. Wendelstein 7-X is intended to prove that the disadvantages of earlier stellarators can be overcome and that stellarator-type devices are suitable for power plants.
https://www.nature.com/articles/s41586-021-03687-w

Giorgio
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Location: China, Italy

Re: Wendelstein 7-X

Post by Giorgio »

Stellarators are still the most elegant design of all experimental fusion apparatus out there.
Getting rid of the need of a poloidal field through geometric design is the road for a compact and steady state fusion device. It will not be the first to achieve fusion, but I strongly believe that Stellarators will become one of the final design candidates for future fusion reactors, especially for space applications. I am deeply curious to see how this will evolve as they will scale up plasma confinement times and energy.
A society of dogmas is a dead society.

Enginerd
Posts: 189
Joined: Sun Feb 07, 2010 5:29 am

Power plasma with gigajoule energy turnover generated for eight minutes

Post by Enginerd »

Wendelstein 7-X: Power plasma with gigajoule energy turnover generated for eight minutes
https://phys.org/news/2023-02-power-pla ... nover.html
"Reality is that which, when you stop believing in it, doesn't go away."
--Philip K. Dick

Giorgio
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Location: China, Italy

Re: Wendelstein 7-X

Post by Giorgio »

There is still lot of road ahead before it can express its full potential, but the results so far are way better than expected.
It's a beautiful piece of engineering art.
A society of dogmas is a dead society.

Skipjack
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Joined: Sun Sep 28, 2008 2:29 pm

Re: Wendelstein 7-X

Post by Skipjack »

Giorgio wrote:
Thu Feb 23, 2023 8:51 pm
There is still lot of road ahead before it can express its full potential, but the results so far are way better than expected.
It's a beautiful piece of engineering art.
Well it is German. So were the Tiger 2 and the V 2. Both were useless.

Giorgio
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Joined: Wed Oct 07, 2009 6:15 pm
Location: China, Italy

Re: Wendelstein 7-X

Post by Giorgio »

Skipjack wrote:
Fri Feb 24, 2023 6:09 am
Giorgio wrote:
Thu Feb 23, 2023 8:51 pm
There is still lot of road ahead before it can express its full potential, but the results so far are way better than expected.
It's a beautiful piece of engineering art.
Well it is German. So were the Tiger 2 and the V 2. Both were useless.
From a practical point of view you are right, WX-7 will indeed not have many applications except pure research. But from an engineering elegance point of view it is way ahead of anything out there and will probably serve as a technological base for future advancements. This was also the destiny of the Tiger-II and V-2 if you look back at history.

I am not a big fan of German engineering in general (pre-war or post war) , but credit must be given where is due.
A society of dogmas is a dead society.

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