Wendelstein 7-X

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

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Giorgio
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Re: Wendelstein 7-X

Postby Giorgio » Tue Dec 15, 2015 8:57 pm

Firstly, let me excuse again if my previous posts was sounding non polite to you. As i said this was not my original intention.

If sometimes I tend to be rude it happens only with people with whom (after long and fruitless attempts) I lost any hope of a scientific and/or meaningful discussion. I can't obviously place you in such a category.
Having (hopefully) cleared the misunderstanding let me reply to your arguments:

Robthebob wrote:1. "The absence of a net plasma current leads to an inherent steady-state operation." This doesnt matter, because neutral injections in Tokamaks have "fixed" the steady-state operation problem, but none of it matters, cus neutral injections can be done in Stellarators, (mainly to bring it to H-mode, something something)

2. "No need to input power to keep a stable magnetic configuration means that the Plasma can actually burn continuously." No man, they need neutral injections to bring the machine to H-mode; even if somehow Stellarators doesnt require H-mode, there's likely to be beta limiting factors, which means you need H-mode, something something.

...........

In the Tokamak the Poloidal Magnetic Field is generated by a strong current parallel to the Toroidal Field. This strong current is induced by the central transformer that can only be active for a limited time, hence the Tokamak cannot be steady state.
Neutral Beam Injection, have partially solved this issue in Tokamak, but at the expenses of more complex system and a bigger consumption of auxiliary power. This makes the system more prone to Aux System Failures, Mechanical Failures (cyclic environment for magnetic and thermal stress over almost any component of the machine), and to a lower general electrical efficiency of the whole system.

In the Stellarator the Poloidal Field is created by the special coils wound around the torus, hence NO need for secondary system to generate it like in the Tokamak.
Additionally, because the the current is in the external coils, it does not suffer from the limit of a central transformer (that can only work for a limited time like the Tokamak Poloidal Generator) and it allows the Stellarator to work in a "Poloidal" Steady State.

Also, in the last few years of research on different types of Stellarators it has been realized that out of the various systems available to heat the Plasma in a Commercial Stellarator like the HSR4/18i, it is the Electron Cyclotron Resonant Heating system (ECRH) that is best suited for the Job, and not the Neutral Beam Injection (NBI).
The ECRH emits microwaves that are at the same frequency as the Electron Gyration frequency in the Plasma, this allows the waves to be absorbed by the electrons and thermalized by collision, thus heating the plasma.
Once the Fusion reaction starts the Apha particles from fusion will take over the task to heat the plasma in a self heating situation. Carefully removing the heat from the Plasma will make the reactor reach an equilibrium point allowing it to work in a "Thermal" Steady State.

The W7-X experiment is equipped with both, NBI and ECRH to test also these important issue.
I have a lot of recent and old papers on the above points. If you (or anyone else) are interested to read them just let me know and I will manage to post them here.



Robthebob wrote:
Giorgio wrote:"I Really can't think anything that is part of a Tokamak that would improve the already elegant physics and strong stability present inside a Stellarator plasma. But I am always open for suggestions and discussions."


I dont disagree, I'm saying, it's a Tokamak world out there, and if what needs to be demonstrated is that Stellarators can essentially do anything a Tokamak can do, so people can get on the "right train".

Ok, I understand what you mean now and I agree on this. In the first post you made I thought you wanted to point out that an hybrid Stellarator/Tokamak system would have been more efficient than a pure Stellarator system. This is not something I can imagine/visualize, and that's why I asked for some detailed clarification.



Robthebob wrote:I think we can probably go back to the drawing board to make things be even better... just a thought.

I think W7-X will clear MANYmany of the doubts still pending on defining if the best road to a commercial machine will be based on a Tokamak or on a Stellarator Design.
Than of course the real issue will be what politics will decide.....



Robthebob wrote:Hybrid machines research are still going strong at Auburn as far as I know. What I was trying to convey is the features of Stellarators and Tokamaks are not mutually exclusive, and it's not conjecture, it's been done, it's still going.

All the info I have is that they are just modelling MHD disruption patterns. Even with a google search I could not find much more than that and nothing of relevant in the last years. If you have anything interesting feel free to post, I am always looking for new stuff to read while I wait sun rise.
Look, stars!

Solo
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Re: Wendelstein 7-X

Postby Solo » Wed Dec 16, 2015 5:26 pm

The interesting thing about what they are doing at Auburn is the disruption prevention. Driving the current in a tokamak is one challenge, but that may be partly met by leaning on the bootstrap current to reduce the current drive demand. The other issue is that current disruptions are hazardous and seem difficult to eliminate. The idea with Auburn's experiment is to see whether current disruptions can be either prevented or made less disastrous by incorporating a limited amount of helical shaping to provide some rotational transform to the plasma without current [the two reasons for tokamak currents are (a) ohmic heating, but this is only for startup (b) providing the rotational transform to keep the plasma stable]. That way, if the current starts to quench, the vacuum magnetic field 'catches' the plasma before it totally collapses. Maybe. So it's actually very cool research, and they are still publishing/doing experiments. They are hosting a conference in February, you should be able to find out more when they post the presentations online

Robthebob
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Re: Wendelstein 7-X

Postby Robthebob » Wed Dec 16, 2015 11:27 pm

You guys.... I knew most of that already.

I'm really confused what the confusion is. Giorgio, we should continue this conversation on another platform like phone or something. I literally explained everything as clearly as I could. I don't think you understand what I was talking about.

But seriously tho, despite all of the solutions to toroidal magnetic confinement, none of that matters, cus they ultimately can't make a low q net energy small and not complex toroidal magnetic confinement machine. The other paths, like polywell, is still better.

PS: Solo, how you know about stuff Auburn is doing? lol, not many ppl (even in the field) do.
Throwing my life away for this whole Fusion mess.

Giorgio
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Re: Wendelstein 7-X

Postby Giorgio » Thu Dec 17, 2015 6:17 pm

Robthebob wrote:I'm really confused what the confusion is. Giorgio, we should continue this conversation on another platform like phone or something. I literally explained everything as clearly as I could. I don't think you understand what I was talking about.


My confusion comes from the different positions that seems to emerge from your posts:
Robthebob wrote:So a lot of folks in this thread thinks that the tokamakness and stellaratorness are mutually exclusive. This is not true, you can build a hybrid machine to take advantage of all the advantages of tokamaks and stellarators, at the same time.

And than this:
Robthebob wrote:I dont disagree, I'm saying, it's a Tokamak world out there, and if what needs to be demonstrated is that Stellarators can essentially do anything a Tokamak can do, so people can get on the "right train"

In the first post you present the possibility to make an Hybrid machine, that's why I asked details and explanation about what you had in mind.
In the second you seem to indicate that we should prove Stellarator are actually better at doing what a Tokamak does, and that's where I indicated where a modern Stellarator design is already better than a Tokamak equivalent, overcaming many Tokamak limitations.

Now you post this:
Robthebob wrote:But seriously tho, despite all of the solutions to toroidal magnetic confinement, none of that matters, cus they ultimately can't make a low q net energy small and not complex toroidal magnetic confinement machine. The other paths, like polywell, is still better.

So, to understand, what's your position? To buil an hybrid machine with a mix of Tokamak and Stellarator features as you suggested or to drop any research in favour of the Polywell?

Because for me of course the Polywell idea is better than a Tokamak and a Stellarator, but there is no money nor research going on in Polywell now, almost all investments are in the Tokamak and Stellarator. For me I just care that one of them (or anything else) will reach a viable solution for a commercial reactor because that's the moment when there will be truckloads of money flooding into fusion research to verify the feasibility of all the idea out there in the aim to find a commercial advantage. And that will finally give the chance to the Polywell to be properly researched.
Look, stars!

Robthebob
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Re: Wendelstein 7-X

Postby Robthebob » Fri Dec 18, 2015 6:17 am

we should move this to another platform, like phone or skype. PM if you would like to continue the conversation, although, there's not much more we can talk about that I havent already covered.
Throwing my life away for this whole Fusion mess.

paperburn1
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Re: Wendelstein 7-X

Postby paperburn1 » Fri Dec 18, 2015 2:02 pm

As for no money going into polywell , with a little luck that may change. It has been no secret that Park is beating the bushes for investors, more importantly investors that can see this though to the end.
And now we have this tidbit out of the climate talks:
Gates will announce the creation of a multibillion-dollar clean energy fund on Monday at the opening of a Paris summit meeting intended to forge a global accord to cut planet-warming emissions, according to people with knowledge of the plans.
The fund is meant to pay for research and development of new clean-energy technologies. It will include contributions from other billionaires and philanthropies, as well as a commitment by the United States and other participating nations to double their budget for clean energy research and development, according to the people with knowledge of the plans, who asked not to be identified because they were not authorized to discuss the fund.
So maybe? :wink:
I am not a nuclear physicist, but play one on the internet.

ladajo
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Re: Wendelstein 7-X

Postby ladajo » Fri Dec 18, 2015 2:43 pm

Unfortunately, to date, US money is only interested in the subsidies leveraged returns on solar and wind. They see the argument as a profit margin one. Much more profit to be had when the government is pouring tax money into it to support investment returns.
If fusion ever sees similar support, then I predict the willingness of US investors to fund it will improve accordingly.
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)
What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

Giorgio
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Re: Wendelstein 7-X

Postby Giorgio » Sat Dec 19, 2015 3:17 am

Robthebob wrote:we should move this to another platform, like phone or skype. PM if you would like to continue the conversation, although, there's not much more we can talk about that I havent already covered.

If you feel that you already covered all your points than indeed there is not much more to talk about.
Unfortunately (for me) I didn't get them. Hopefully someone else who got your point will be willing to argue them and to keep the discussion going.
Last edited by Giorgio on Sat Dec 19, 2015 6:28 am, edited 1 time in total.
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Giorgio
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Re: Wendelstein 7-X

Postby Giorgio » Sat Dec 19, 2015 5:04 am

Solo wrote: They are hosting a conference in February, you should be able to find out more when they post the presentations online

Thanks. I placed a Google alert for it. Hopefully they will publish some papers at the end of the conference.
Look, stars!

Robthebob
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Re: Wendelstein 7-X

Postby Robthebob » Sun Dec 20, 2015 2:22 am

that's unfortunate, your loss tho.

What I meant to say is, I covered the points, but you didn't get them. But that's not correct either, I think you just didn't attempt to learn the points I made.

Happens a lot on the internet, complete arguments are cheer picked apart, while the rest never goes through. Not sure what I should do when I repeated all my points twice, lol... what should I do?
Throwing my life away for this whole Fusion mess.

Giorgio
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Re: Wendelstein 7-X

Postby Giorgio » Sun Dec 20, 2015 4:09 pm

Robthebob wrote:Happens a lot on the internet, complete arguments are cheer picked apart, while the rest never goes through. Not sure what I should do when I repeated all my points twice, lol... what should I do?


As a start you could reply to this question I asked:
Giorgio wrote:So, to understand, what's your position? To buil an hybrid machine with a mix of Tokamak and Stellarator features as you suggested or to drop any research in favour of the Polywell?
Look, stars!

crowberry
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Re: Wendelstein 7-X

Postby crowberry » Mon Feb 01, 2016 7:33 pm

The first hydrogen plasma on 3 February 2016 will mark the start of scientific operation of Wendelstein 7-X. 

You may care to pursue the event per livestream on 3 February 2016 at 2.45 p.m.:

http://www.ipp.mpg.de/livestream_e_16

http://www.ipp.mpg.de/4010488/livestream_16

AcesHigh
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Re: Wendelstein 7-X

Postby AcesHigh » Wed Feb 03, 2016 7:27 pm

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?

http://www.iflscience.com/physics/germa ... orld-first

"Germany's Fusion Reactor Creates Hydrogen Plasma In World First"

"Last December, the team managed to suspend a helium plasma for the first time in history, and they’ve now achieved the same feat with hydrogen. Generating a hydrogen plasma is considerably more difficult than producing a helium one, so by producing and sustaining one in today’s experiment, even for just a few milliseconds, these researchers have achieved something truly remarkable."

ladajo
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Re: Wendelstein 7-X

Postby ladajo » Wed Feb 03, 2016 7:39 pm

Was not WB6 and 7 tested with H2 gas? ie. Generated H2 plasma?
The development of atomic power, though it could confer unimaginable blessings on mankind, is something that is dreaded by the owners of coal mines and oil wells. (Hazlitt)

What I want to do is to look up C. . . . I call him the Forgotten Man. (Sumner)

Skipjack
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Re: Wendelstein 7-X

Postby Skipjack » Wed Feb 03, 2016 10:14 pm

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...


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