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PostPosted: Tue May 26, 2009 9:56 am 
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Art Carlson wrote:
The FRC is formed with a high velocity and then is shot into a confined space where it is brought to a halt.
OK. Sure, I can see that. A self-reacting field as the density increases. If it can remain stable then I guess it has 'a shot' at doing some useful fusion. I'm not confident it will remain stable though, like a big crowd trying to get through a small gate, they'll spread out as they approach the high density. Rotation might not help any, either - if you watch water down the plughole, that air in the middle of the vortex isn't very dense!!


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PostPosted: Tue May 26, 2009 10:29 am 
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chrismb wrote:
Art Carlson wrote:
The FRC is formed with a high velocity and then is shot into a confined space where it is brought to a halt.
OK. Sure, I can see that. A self-reacting field as the density increases. If it can remain stable then I guess it has 'a shot' at doing some useful fusion. I'm not confident it will remain stable though, like a big crowd trying to get through a small gate, they'll spread out as they approach the high density. Rotation might not help any, either - if you watch water down the plughole, that air in the middle of the vortex isn't very dense!!

There are two macroscopic MHD instabilities to worry about.

First, these babies tend to rotate around the axis. If they do that fast enough (which they do), then they tend to start bulging on two sides and get thinner on the other two sides, so the plasma looks elliptical when viewed end-on. Think of it as a Raleigh-Taylor instability. Fortunately, this instability can be brought to a halt at a small amplitude by putting multipole fields around the outside. (Sort of like a polywell in that the field is small on axis and increases as you move out.)

Second is the tilt instability. If you think of the FRC as a current ring in a magnetic field, it is pointing the "wrong way". The energy would be lower if it could flip over 180 degrees. Of course, if it did that, it would spill its guts. If the gyro-orbits and the length of the configuration are both big enough compared to the radius, then this doesn't happen. The configuration is stabilized by non-ideal MHD effects. Experiments have been surprisingly stable in this respect, but if you want to extrapolate an FRC to a reactor, this severely limits the available parameter space.

Another factor, I believe, is the size of the plasma relative to the chamber. An FRC in a uniform field without boundaries would flip over no matter what. It is important that FRCs are made in flux conserving cylinders and fill up a fair portion of the cross section. Keep that in mind before applying too simplistic ideas.

Transport - microscopic MHD instabilities, if you will - are another matter. But we can talk about that another day.


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PostPosted: Tue May 26, 2009 10:51 am 
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So basically your interpretation is that the FRC is a magnet facing the wrong way in a magnetic field, and the hope is it will stay pointing the wrong way in a perfect, meta-stable condition.

Having just built a magnetic assembly, that is SOME hope!!!

Having reviewed many approaches, 'clever invention/ideas' usually seem to forget and hope-beyond-hope that meta-stable condition can be balanced on a pin-head somehow and it all looks great whilst on that pin-head of stability and the equations all balance. And in experimentation it is sure to work.... if only it weren't for those pesky small perturbations which upset that balance, or put the system into oscillations. I have expressed the same concern over certain aspects of Polywell many times.

It's like people go looking JUST for a dy/dy=0 condition and say 'hey, stability!!! Let's test it!'. Even those that spot they need to also find d2x/dy2>0 (on both sides of the condition) then often appear to forget d2x/dt2=-kx!


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PostPosted: Tue May 26, 2009 11:36 am 
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chrismb wrote:
So basically your interpretation is that the FRC is a magnet facing the wrong way in a magnetic field, and the hope is it will stay pointing the wrong way in a perfect, meta-stable condition.

I agree, it looks like the first guy to make an FRC wasn't paying attention to elementary stability theory. But he tried it anyway and it worked. And it kept working. And then the theorists had to earn their keep by trying to figure out why it didn't self-destruct. In the meantime, the experimentalists and the theorists seem to agree that the plasma behaves itself as long as s/epsilon is greater than 0.4.


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PostPosted: Wed May 27, 2009 8:01 pm 
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Excuse my bad English. Hope you understand watt I want to say.

Its looks like this devise have a good chance for success.
Art Carlson want to make us into FRC fans. But there is terrible little info about this. For example the Wikipedia article is short and have no external links.

There are several questions about FRC. Some of them have been answered in this tread.

How do we make fusion from FRC? We have the helon concept, DPL and the sustained plasma in the tokamak way. Are there more ways to make fusion in a FRC?

Who invented the FRC?

What research is done on this?

Watt is the biggest critique of the FRC?

Can it be possible to burn D+D fuel in a FRC?

The FRC plasma is said to be stabile. How stabile? There from come this stability?

Can I make a FRC at home?

I have made a picture of the Helion concept.
http://i246.photobucket.com/albums/gg11 ... ELIONs.jpg
<a href="http://s246.photobucket.com/albums/gg111/Torulf2/?action=view&current=HELIONs.jpg" target="_blank"><img src="http://i246.photobucket.com/albums/gg111/Torulf2/HELIONs.jpg" border="0" alt="energy fusion nuklear green FRC,helion 3d"></a>
Image

And an animated gif.
http://i246.photobucket.com/albums/gg11 ... ion-a2.gif

<a href="http://s246.photobucket.com/albums/gg111/Torulf2/?action=view&current=Helion-a2.gif" target="_blank"><img src="http://i246.photobucket.com/albums/gg111/Torulf2/Helion-a2.gif" border="0" alt="energy fusion nuklear green FRC"></a>

Image


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 Post subject:
PostPosted: Thu May 28, 2009 3:44 am 
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That looks uncannily like a warp core.


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PostPosted: Thu May 28, 2009 6:34 am 
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An order of magnitude here. an order of magnitude there and suddenly you need 100 metre long tubes to accelerate the vortical plasmoids through (http://www.springerlink.com/content/g1504v484553nn47/) .... snake them all around the ship through the plasma conduits and hey presto ... a bona fide warp core.

My personal favourite is Moffat and Moore's rotational axisymmetric solution, Hill's spherical vortex with swirl ..... it's fundamental mathematical solutions that get us there, not cartoon engineering.
http://journals.cambridge.org/action/displayAbstract;jsessionid=4A7E09F1765AF13EF573D815B21962AE.tomcat1?fromPage=online&aid=450726


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PostPosted: Tue Jun 09, 2009 10:42 pm 
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Look at there new graphics.
http://www.helionenergy.com/


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PostPosted: Wed Jun 10, 2009 9:09 am 
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Torulf2 wrote:
Look at there new graphics.
http://www.helionenergy.com/


Torulf, I assume you are the guy who made the graphic for that website. Why isn't there any information there about who is involved in the project? It's so anonymous it has a high scam feel to it.


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PostPosted: Wed Jun 10, 2009 11:46 am 
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Go to "fusion engine" there is an animaion and there is the information.


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PostPosted: Wed Jun 10, 2009 1:26 pm 
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Wouldn't be cheaper to buy polar bears boats and teach them how to operate them? Or perhaps hire operators? GREEN JOBS!!!

Note: in an attempt to keep polar bear populations in check Canada is killing 800 a year.

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PostPosted: Wed Jun 10, 2009 2:03 pm 
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MSimon wrote:
Wouldn't be cheaper to buy polar bears boats and teach them how to operate them? Or perhaps hire operators? GREEN JOBS!!!

Note: in an attempt to keep polar bear populations in check Canada is killing 800 a year.


Simon, what does this have to do with the topic of the thread?

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PostPosted: Wed Jun 10, 2009 2:23 pm 
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Aero wrote:
MSimon wrote:
Wouldn't be cheaper to buy polar bears boats and teach them how to operate them? Or perhaps hire operators? GREEN JOBS!!!

Note: in an attempt to keep polar bear populations in check Canada is killing 800 a year.


Simon, what does this have to do with the topic of the thread?


You might want to take a look at

http://www.helionenergy.com/Helion_Pres ... n-Web2.pdf

there is a hint at the end.

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PostPosted: Wed Jun 10, 2009 5:07 pm 
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Torulf2 wrote:
Go to "fusion engine" there is an animaion and there is the information.


I went there. Nice animation. Pretty effects. No names listed though. Your site is very thin on details. Really thin. Anemic. I am left wondering who the hell is involved in this project and why they would tolerate a website that kept their identities secret like some mafia scam.


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PostPosted: Wed Jun 10, 2009 6:23 pm 
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IntLibber wrote:
Torulf2 wrote:
Go to "fusion engine" there is an animaion and there is the information.


I went there. Nice animation. Pretty effects. No names listed though. Your site is very thin on details. Really thin. Anemic. I am left wondering who the hell is involved in this project and why they would tolerate a website that kept their identities secret like some mafia scam.
It's probably just embarrasment. I mean, making a claim that '90% collision energy efficiency' - presumably that means 90% of the collision energy results in fusion events - the residence time of an ion at fusible energy must surely be several minutes, yet surely this is a flash-in-a-bottle stuff with almost no residence time for fusible ions, and thus a very low efficiency (not that that's necessarily a problem if the energy outputs are high enough, but it puts a question mark over the maths)?


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